PeptoPro experience and review

Geschatte leestijd: 29 minutenPeptoPro is hydrolyzed protein whose long amino acid chains have already been partially broken down by enzymes, resulting in faster absorption. This means that the amino acids from PeptoPro are absorbed more quickly than those from whole proteins like whey, as well as faster than individual amino acids.

Table of Contents

• PeptoPro®
• Introduction of PeptoPro at the 2004 Olympics
• What is PeptoPro?
• Di- and tripeptides
• Hydrolysis of protein
  • Degree of hydrolysis
  • Molecular weight
• Official information on PeptoPro is difficult to obtain
• Faster absorption of amino acids from di- and tripeptides
• (Di- and tri)peptides faster than complete proteins and free amino acids
• Distinguishing di- and tripeptides and other short chains: peptide-carrier system
• In addition to faster absorption, more complete absorption from di- and tripeptides
• Contradictory sources on faster absorption of hydrolyzed protein
• Different measurement methods can lead to misleading results!
• Hydrolyzed protein and its role in insulin
• More insulin means more muscle mass?
• Faster recovery with hydrolyzed casein? Recovery of glycogen storage
• Recovery of glycogen storage in muscles
• Differences in amino acid profiles between whey and hydrolyzed casein.
• “Hydrolyzed casein reduces body fat”
  • “Hydrolyzed casein reduces body fat percentage more than full casein in mice.”
  • “Casein hydrolysate reduces body fat more than whey hydrolysate and promotes more muscle mass.”
  • Personal experience
    • Ease of use
    • Taste
    • Price of PeptoPro
  • “But it does work”
  • Would I buy PeptoPro®?
  • Summary and conclusion of PeptoPro
    • References:

  PeptoPro®

  As the first review of a supplement offered by Bodyenfitshop, I’m reviewing PeptoPro® from DSM. I haven’t exactly chosen the easiest product to write a review about.

  The name PeptoPro® is derived from peptides. Very short chains of amino acids in which protein has been broken down through the process of so-called hydrolysis. In the case of PeptoPro®, protein in the form of casein has been used for this purpose. These short chains are supposed to be absorbed faster than both individual amino acids and the complete, long chains of amino acids from which proteins are built. This faster absorption is said to have several benefits such as more muscle growth, higher fat burning, and faster recovery after intense exercise.

  So, PeptoPro® consists of hydrolyzed casein. However, not all hydrolysates are the same. The difficulty in evaluating PeptoPro® lies in finding relevant studies that have used similar hydrolyzed casein. Studies on PeptoPro® itself are very limited. Additionally, there are differences in the quality and conclusions of various studies, making a clear conclusion difficult, if not impossible.

  Finally, one may also wonder what a product like PeptoPro® should be compared to in a study. With casein? Yes, that is useful to know if the hydrolyzed version offers benefits compared to the non-hydrolyzed, “normal” casein. But when it comes to absorption speed, comparisons with individual amino acids, whey, and hydrolyzed whey, all known and popular for their rapid absorption, are more interesting. In the studies I mention for this article, different choices have been made by the researchers regarding what the hydrolyzed casein is compared with. This can make the studies themselves sometimes harder to compare.

  Finally, there are many studies that demonstrate the added value of hydrolyzed casein in general or PeptoPro® in particular, but do not compare them with other forms of protein or amino acids at all. I have largely ignored these studies. For example, it is of little added value to know whether you perform better with carbohydrates and PeptoPro® than with carbohydrates alone (the same applies to questions about the effect on muscle mass, fat burning, muscle pain, etc.). If this is not compared to other protein/amino acids, it mainly indicates the added value of protein in general, and you still don’t know to what extent other, cheaper, protein could have achieved the same result. It’s like praising the latest Ferrari without comparing it to other sports cars in the same segment.

  Based on various perspectives, I will discuss and compare as many relevant studies as possible, hoping that this will help you form a well-founded opinion on the added value of PeptoPro®.

  Introduction of PeptoPro at Olympic Games 2004

  PeptoPro® was introduced at the 2004 Olympic Games as the official sports drink of NOC*NSF (as part of the DSM sponsorship program for NOC*NSF), in the form of Total Recovery Drink. The downside at the time was that it was delivered in sachets of 37.5 grams of powder, of which only 12.5 grams was PeptoPro®. The rest consisted of simple carbohydrates. Although this was the recommended dosage of PeptoPro® after intense exercise, it meant that athletes had to carry a large number of these sachets with them.

  Furthermore, athletes complained about the taste of the drink, which was very bitter. DSM worked on this before introducing PeptoPro® in its current, pure powder form. Total Recovery Drink is still sold alongside it.

  What is PeptoPro?

  PeptoPro® from DSM consists of 85% casein protein, of which 7.5% is free amino acids, 8.5% is dipeptides, and 39% is tripeptides.

  To understand what distinguishes PeptoPro® from “normal” protein, it’s useful to know the terms di- and tripeptides as well as hydrolysis (in addition to the more commonly known terms amino acids and protein). Therefore, I’ll start with a somewhat technical story that I’ve tried to keep as simple as possible.

  Di- and Tripeptides

  Protein is formed by long chains of amino acids that are linked together by so-called peptide bonds (1). These are broken down into shorter chains of amino acids for further use by the body in the stomach and small intestine. Chains of amino acids can have various lengths:

  • Monopeptide: One amino acid
  • Dipeptide: Two amino acids with one peptide bond
  • Tripeptide: Three amino acids with two peptide bonds
  • Tetrapeptide: Four amino acids with three peptide bonds
  • etc. (pentapeptide, hexapeptide, heptapentide, octapeptide, nonapeptide, decapeptide)

  Chains of more than 10 amino acids are called polypeptides. A protein consists of one or more polypeptides. Some polypeptides are also called proteins and vice versa because there is no fixed rule for the number of amino acids a polypeptide can contain before it is called a protein. Sometimes, 50 amino acids are considered the upper limit for a polypeptide.

  Examples:

  Three individual amino acids (structural formulas)

  A tripeptide consisting of the amino acids Alanine, Glycine, and Phenylalanine (structural formula)

  A polypeptide (simplified representation with abbreviations of amino acids instead of structural formulas)

  Hydrolysis of Protein

  Hydrolysis of protein is the process by which the longer chains of amino acids that make up the protein are broken down into smaller chains. This occurs in the body by the protease enzyme (also called peptidase or proteinase). There are various types of protease, each breaking the bonds at different locations of the chain.

  DSM achieves this breakdown into smaller chains by a “patent-protected enzyme” that also reduces the bitter taste that is normally characteristic of pre-hydrolyzed proteins (2).

  Degree of Hydrolysis

  The degree of hydrolysis is the percentage of peptide bonds between the amino acids in the chain of a protein that have been broken by the enzymes (3). In other words, the higher the degree of hydrolysis, the greater the number of shorter chains into which the protein is broken.

  PeptoPro® has a degree of hydrolysis of 28%-30%. This is considered very high. Products with a higher degree of hydrolysis are often too bitter in taste to be appealing for sale.

  Each protein hydrolysate is a complex mixture of peptides of different chain length together with free amino acids, which can be defined by a global value known as degree of hydrolysis (DH), which is the fraction of peptide bonds that have been cleaved in the starter protein [3]. However, even the exact information on DH cannot tell us the whole story, as two protein hydrolysates made by different methods (e.g., oligopeptides/significant free amino acids vs. mainly dipeptides and tripeptides) may have a similar degree of hydrolysis even though their absorption kinetics are likely quite different. Consequently, all protein hydrolysates are certainly not created equal.
  A.H. Manninen, Manninen Nutraceuticals (2009)

  Molecular Weight

  A final, important characteristic of hydrolyzed protein is the so-called molecular weight. This is important because it affects the rate of absorption in the blood (4,5). It is expressed in Dalton, or kilo Dalton (kDa).

  For example, whey protein consists mainly (58%) of β-lactoglobulin, which has a molecular weight of 18,277 Dalton, or 18.277 kDa (6). In addition, whey consists of 20% α-lactalbumin with a molecular weight of 14,175 Dalton (7). In the image next to this, you can find these in the protein profile of whey (8).

  PeptoPro® has an average molecular weight of less than 1,000 Dalton. 60% of PeptoPro® even has a molecular weight of less than 500 Dalton. At least according to various sellers of PeptoPro® who claim to have obtained this information from DSM. I can only find information from DSM in the form of an interview with Stefan Steinbacht, Director Business Development, in which he talks about “the lowest molecular weight of all pre-digested protein (9).

  Regarding molecular weight, you would therefore expect that PeptoPro® ensures faster absorption of the amino acids it contains compared to regular, complete protein.

  Official Information on PeptoPro Difficult to Obtain

  I requested DSM to provide the official data on PeptoPro® three weeks before the publication of this article regarding degree of hydrolysis, percentage of amino acids, percentage of di- and tripeptides, and molecular weight. To date, I have not received a response. The official websites contain either marketing-oriented information in the form of spectacular statements about effectiveness or show a blank page. As a company proud of its products, it seems to me that you should make this information accessible. Whether this is a matter of poor website management or something else is unknown to me.

  Faster Absorption of Amino Acids from Di- and Tripeptides

  The main added value of PeptoPro® would lie in the high content of di- and tripeptides and the speed at which the amino acids in these are absorbed into the blood. After all, a faster availability of amino acids ensures that the muscles have the necessary building blocks to build tissue after training and prevents breakdown of muscle tissue (10,11).

  There are several studies that have compared the absorption rate of hydrolyzed protein with the absorption of complete protein. Of these studies, several concluded that specifically the di- and tripeptides (of both whey and casein) are absorbed more quickly (12,3,13,14,15,16,17,18).

  One study to which DSM itself seems to refer is that of Adibi and Morse from 1977 (19). At least, that’s the study referred to in the image on the right. In this graph, the absorption rate of four forms of amino acids is examined: Free amino acids, di-peptides, tri-peptides, and tetra-peptides. The graph as shown here does not appear in the study itself. This is the graph as DSM itself has drawn based on the graphs depicted in the study. Understandable because the original representation requires more explanation. However, the image is the same as shown in (right side of) the original graph below.

  Researchers from the University of Pittsburgh compared the speed at which glycine, the smallest of the 20 different amino acids in protein, was absorbed into the blood. In the image on the right, you can see two graphs. The difference between these is the amount of solution administered with the various peptides. In graph “b,” twice as much was administered as in “a,” making the differences larger and therefore clearer.

  You can see in the graph the different speeds at which glycine in the form of tetra-peptides, tripeptides, dipeptides, and as “free” amino acid (monopeptide) is absorbed into the blood. It is clear that di- and tripeptides are absorbed more quickly than tetra-peptides, and these in turn are absorbed more quickly than monopeptides.

  (Di- and tri)peptides faster than complete protein and free amino acids

  In practice, complete protein and free amino acids are very popular as dietary supplements. So, it’s the very long (combination of) chains or just the free amino acids that are sold.

  There are two reasons why free amino acids are popular. Firstly, with the purchase of free amino acids, you can determine the composition of the amino acids yourself (while they have a certain composition of the 20 amino acids of which the amount per amino acid depends on the type of protein). The other reason is the speed at which these amino acids enter the blood where they can do their work. For a quick recovery immediately after training, these are popular due to faster absorption.

  Common sense would probably lead you to believe that free amino acids are absorbed more quickly than amino acids from di- and tripeptides. However, as shown in the graph above (and other research), this is not the case (19,20).

  The rates of glycine uptake were always markedly greater from diglycine and triglycine solutions than from corresponding glycine or tetraglycine solutions…

  Siamak A. Adibi, University of Pittsburgh

  Distinguishing Di- and Tripeptides and Other Short Chains: Peptide Carrier System

  Although the graph also shows that tetra-peptides are absorbed more quickly than free amino acids, a clear difference can be seen between these and the di- and tripeptides. The researchers attribute this to the different ways in which di- and tripeptides are transported to the blood (19,13).

  Earlier research by the same researchers had already shown that di- and tripeptides are transported to the blood in a different way than free amino acids and longer chains (21,22). This so-called peptide carrier system has a few interesting properties including (21,22,23,24):

  • It does not transport free amino acids but does transport dipeptides and some tripeptides.
  • It has a higher maximum absorption rate than the transport system for free amino acids.
  • It is an important, if not the predominant, transport system for amino acids in protein.

  The researchers’ conclusion is therefore that chains longer than di- and tripeptides must first be hydrolyzed into di- and tripeptides, making them absorbed more slowly (

  19,25). Chains that are only slightly longer than di- and tripeptides are so short that despite the delay due to hydrolysis, they are still faster than the free amino acids following the other transport system. The threshold for this seems to be a chain of six amino acids (hexapeptide). For longer chains, the delay due to hydrolysis is such that the transport system for free amino acids is faster (19).

  …the rate limiting step in the uptake of glycine from tetraglycine or higher peptides is due to hydrolysis of these peptides to absorbable products. When the number of glycine residues was increased to hexaglycine, the phenomenon of a greater rate of glycine uptake from a peptide versus a free amino acid solution was no longer apparent.

  Siamak A. Adibi, University of Pittsburgh

  Besides Faster Absorption, Also Fuller Absorption from Di- and Tripeptides

  When amino acids are used in the form of di- and tri-peptides, they not only arrive faster, but also in greater quantity in the blood than when taken in longer chains or free amino acids (3,13,26).

  This has to do with the previously mentioned difference in the way free amino acids on the one hand and di- and tripeptides on the other hand are transported along the stomach, intestines, pancreas, spleen (referred to as portal drained viscera or PDV), and liver.

  The so-called first-pass extraction is the amount of amino acids that are “separated” by these organs and amounts to about 20 to 35 percent. This amount is therefore not available in the blood (26). In the case of hydrolyzed protein, the PDV would be “less efficient” in separating these amino acids, leaving more available in the blood, ultimately available for absorption by the muscles.

  Different Measurement Methods Can Lead to Misleading Results!

  In another study, the whey hydrolysate Optipep from Carbery Foods (also a supplier of the whey hydrolysate from Bodyenfitshop) with a degree of hydrolysis of 30% was examined (28). In terms of degree of hydrolysis, it is comparable to DSM’s PeptoPro®, although the amino acid profile differs somewhat (due to the difference between whey and casein). They looked at the rate of gastric emptying, the speed at which food leaves the stomach and enters the small intestine. These researchers also observed no (significant) difference in the rate of gastric emptying between whey and hydrolyzed whey. They took into account that this might be due to the intake being done on an empty stomach.

  In addition, they, like in the aforementioned study, looked at the increase in BCAAs in the blood. They also observed that after intake of complete whey, it increased slightly more than after intake of whey hydrolysate.

  Another outcome of the study was that the insulin level in the blood increased more after intake of the hydrolysate (28), but more on that later.

  Hydrolyzed Protein and its Role in Insulin

  I recently wrote about the anabolic properties of the hormone insulin. Insulin is used (among other things, in the treatment of diabetes) and abused (as doping) to take advantage of the signal it sends to the muscles to promote protein synthesis (muscle protein synthesis and thus muscle growth).

  The main regulator of insulin is glucose. Eating sugars/carbohydrates leads to conversion into glucose in the blood. To regulate the amount of glucose in the blood (the “blood sugar level”), insulin is produced, which instructs the muscles to take up glucose and store it as glycogen and to convert amino acids in the blood into protein in the muscles.

  Especially the amino acid leucine is said to have a stimulating effect on the production of insulin provided that the amount of glucose in the blood is increased (30). In the previously mentioned Dutch study, we saw that, among other things, leucine in the blood increased more after intake of casein hydrolysate than after intake of regular casein (29). So it’s not surprising that hydrolysates would lead to a greater increase in insulin than their normal counterparts (31,32,33,34,35).

  While earlier studies on hydrolysates have shown some differences in absorption rate, they often show the same results when it comes to the influence on insulin (28,29,36). Several studies have shown that hydrolyzed protein leads to a higher increase in insulin than “normal” protein.

  It’s unfortunate, however, that there are no studies comparing the effect of casein hydrolysate to whey hydrolysate, so one cannot form an opinion on which one increases the insulin level more.

  More Insulin Means More Muscle Mass?

  This seems to be an argument for hydrolyzed protein. According to some, the higher increase in insulin would also contribute to the synthesis of more muscle protein and thus promote muscle growth (31,37,38). However, studies in recent years have shown that while peak levels of certain amino acids in the blood contribute to more muscle growth, peak levels in insulin are not necessary for this effect (39,40). According to these studies, it seems that basal levels of insulin are sufficient to enable protein synthesis (muscle growth) and are enough to reduce proteolysis (muscle breakdown). However, the researchers still find it a complex issue and hope that further research will provide more insight.

  “Thus, can we say at this point that insulin is simply permissive for protein synthesis and suppressive for protein breakdown, but you don’t need much of it to see this effect?”

  S.M. Phillips

  Research from Japan shows a link between increased insulin levels and improved “net protein balance” (the result of muscle building and breakdown) and concludes that increasing insulin only leads to more muscle growth when it increases blood flow to (and delivery of amino acids to) the muscles (41). Strangely, in that study, low doses of local injections led to no change, higher doses led to more muscle protein synthesis without a change in breakdown, while the highest dose had no effect on synthesis and reduced breakdown. The moderate dose had the greatest effect on net protein balance.

  It was already shown in 1990 that insulin only leads to an improved net protein balance in the presence of sufficient amino acids (42). In the case of using PeptoPro® or hydrolyzed casein, this is not a problem because it provides the body with the necessary amino acids. It is therefore only a question of whether the degree of increase in insulin is not too much for the optimal promoting effect on muscle growth and the limiting effect on muscle breakdown.

  To make matters more complicated, there are also animal studies that showed that casein hydrolysate lowers insulin levels instead of increasing them (43). Given the greater number of studies in humans showing an increase in insulin, the assumption of an increase in insulin due to hydrolysates seems more plausible.

  In the case of insulin, more does not always seem to be better, but there must be enough present. Based on current research, it therefore does not seem possible to determine whether the extent to which hydrolysates increase insulin levels more than complete protein also contributes more to muscle growth.

  Faster Recovery with Hydrolyzed Casein? Glycogen Storage Recovery

  The main fuel for muscles is glycogen. However, glycogen is quickly depleted, even after 30-40 minutes of high intensity exercise (44). Glycogen is made from glucose that we get from eating carbohydrates.

  Recovery of glycogen stores is important for various reasons. Think of it as refueling an electric car. Whether it takes 8 hours or 4 hours for your batteries to be fully charged makes a big difference if you have a long journey ahead on the same day. As fuel for the muscles, better recovery of glycogen ensures that you are able to perform again more quickly.

  By ingesting carbohydrates together with protein after exercise, glycogen recovers faster than when you only ingest carbohydrates, as was shown in research from 2002 (45). It is therefore not surprising that researchers were curious whether the type of protein ingested with the carbohydrates could also make a difference.

  In a study from Japan in 2009, the influence on glycogen storage in muscles of whey, whey hydrolysate, BCAAs, and hydrolyzed casein from DSM was compared (46). Because the product from DSM

  was used in this study, you know that it concerns casein hydrolysate with a high degree of hydrolysis, just like PeptoPro® (31). The researchers used 0.8 grams of protein per kilogram of body weight. Subjects did a cycling workout of 90 minutes at 70% of their maximum oxygen uptake (VO2max), followed by six 1-minute sprints. Immediately afterwards they ingested the drink (carbohydrates and protein) and again two hours later. The results can be seen in the figure below.

  

  The researchers found that muscle glycogen recovery was highest in the first two hours after exercise with the hydrolyzed casein. However, it turned out that three hours after exercise there was no difference in glycogen storage between the various protein groups.

  It is therefore not the case that casein hydrolysate ensures faster recovery of glycogen stores, but it can ensure a faster start of glycogen recovery. The researchers suggest that the higher insulin level in the blood may play a role in this. This would ensure that more glucose from the blood is transported into the muscles.

  So, it is not the case that casein hydrolysate ensures faster recovery of glycogen stores, but it can ensure a faster start of glycogen recovery. The researchers suggest that the higher insulin level in the blood may play a role in this. This would ensure that more glucose from the blood is transported into the muscles.

  And because of the short duration of this high level of insulin (30 minutes after intake), there would be less risk of excess glucose being stored as fat.

  Casein Hydrolysate and its Effect on Fat Mass

  Not only muscle growth is important, but fat loss as well. A higher increase in insulin in the blood not only leads to more protein synthesis in the muscles, but also to a lower breakdown of fat. A high level of insulin ensures that the body stores glucose as glycogen in the muscles and liver, and that the body stores fat. This can be desirable for athletes who need to gain weight (such as football players who need to maintain their weight during a tournament), but less desirable for athletes who need to lose weight (such as cyclists who have to climb mountains).

  It is therefore not surprising that research shows that people who have a higher insulin level after a meal have a higher fat percentage (47). Studies have also shown that whey protein can lead to more fat loss than other proteins. This is attributed to the higher increase in insulin (48,49,50). Whether this also applies to hydrolyzed protein is unknown, as there are no studies on this topic yet.

  However, there are already studies that suggest that casein hydrolysate may lead to a reduction in fat mass (51,52,53,54). It is not known exactly how this works, but it may be that the higher increase in insulin increases the fat-burning hormone adiponectin (55).

  So, if your goal is to gain weight, you can use casein hydrolysate as a protein source because it can increase fat storage. If your goal is to lose weight, you might want to avoid it. However, further research is needed to confirm this.

  Conclusion

  Casein hydrolysate (like PeptoPro®) ensures faster recovery of glycogen stores than other proteins. This is because it ensures a faster start of glycogen recovery. Whether this is also the case with whey hydrolysate is unknown, because there are no studies on this topic.

  Casein hydrolysate ensures a higher increase in insulin in the blood than other proteins. This can contribute to more muscle growth and less fat loss. Whether this is actually the case is not known, as there are no studies comparing casein hydrolysate to other proteins. Hydrolysates can also lead to a more sustained increase in insulin than the complete protein, but it is not known whether this contributes to more muscle growth.

  So, it is not the case that hydrolysates always lead to more muscle growth. Whether this is the case depends on how much the hydrolysates increase insulin compared to other proteins, how much they increase it compared to their complete protein, how much they increase it compared to the amount of amino acids they deliver, and how long the increase in insulin lasts.

  So, to say that hydrolysates are always better for muscle growth than complete proteins is an oversimplification. There are many factors that play a role in this.

  So, the debate about hydrolysates will continue for some time to come, I suspect. If you have any questions or comments, please let me know below.

  “Hydrolyzed Casein Reduces Body Fat”

  Whether you recover faster with hydrolyzed protein in general and hydrolyzed casein in particular has not been unequivocally proven with the mentioned studies. Let’s continue and see if PeptoPro® has an added value when it comes to reducing your body fat percentage and what most of us are concerned about: Building muscle mass.

  “Hydrolyzed Casein Reduces Body Fat More Than Full Casein in Mice.”

  The title of the first study I mention in this regard is certainly encouraging (43).*

  (Unfortunately, this is the study that, as one of the few, showed a decrease in insulin after ingestion of casein hydrolysate. If you disregard those results as unlikely (given the other studies), then you are quite selective in accepting research data when you do accept positive results regarding fat burning from that same study.)

  Danish researchers gave mice full casein or hydrolyzed casein. They observed, among other things, that the so-called respiratory exchange ratio (the ratio between the oxygen you inhale and the carbon dioxide you exhale) was lower when casein hydrolysate was consumed. This is an indication that the body starts burning more fat instead of carbohydrates. This and other effects of the hydrolysate resulted in less body fat in the mice.

  The physiological changes induced by hydrolyzed casein ingestion translated into decreased body and adipose tissue masses. We conclude that chronic consumption of extensively hydrolyzed casein reduces body mass gain and diet-induced obesity in male C57BL/6J mice.

  H.H. Lillefosse, University of Copenhagen

  “Casein Hydrolysate Reduces Body Fat More Than Whey Hydrolysate and Increases Muscle Mass”

  “Nice for those mice,” you might rightly think, “but what about humans?” Although this type of research with animals is predominantly done to draw conclusions that can be applied to humans, established results in humans themselves are more convincing.

  American researchers looked at the effects of a 12-week diet with a) calorie restriction (80% of calorie requirement), b) calorie restriction with training and whey hydrolysate (1.5g/kg body weight), and c) calorie restriction with training and casein hydrolysate (1.5g/kg) (50). This is one of those few studies where the hydrolysates of whey and casein were compared, making it much more interesting.

  Their subjects were overweight police officers. Now please, no lame jokes like, “Are we going from mice to rats?” “Did they have to hide the protein in donuts?” or “Overweight American officers, isn’t that a pleonasm?” (you know, like wet rain, white snow). The researchers specifically chose police officers as “ideal subjects” because they form a fairly homogeneous group in the sense that they do work with similar activity levels and rotating schedules that quickly lead to eating carbohydrate- and fat-rich foods (so those donuts after all). At the same time, good physical condition is important for their work, and they would be motivated.

  The results are shown next. All three groups a, b, and c decreased in weight over the 12 weeks (an average of 2.5 kilograms), and the body fat percentage decreased on average from 27 to 25 percent, but there were significant differences. In the group using casein hydrolysate, the average decrease in body fat percentage was 8% (from 26 to 18 percent). In the group using whey hydrolysate, this was “only” half, namely from 27 to 23 percent. The researchers also found that the fat-free mass (mainly muscle mass) in the casein hydrolysate group had also increased twice as much as in the whey hydrolysate group, namely an average of 4 kilograms compared to 2 kilograms. Finally, the same pattern was observed when looking at the increase in strength. This had increased in the casein hydrolysate group by an average of 59% compared to 29% in the whey hydrolysate group. In both reducing body fat percentage, increasing muscle mass, and strength, casein hydrolysate literally worked twice as well as whey hydrolysate.

  We also demonstrated the significant impact of a casein hydrolysate on the rate of decrease in fat and increase in lean mass.

  R.H. Demling, Brigham and Women’s Hospital, Boston

  Unfortunately, this is the only study I could find that really looked at the ultimate result of casein hydrolysate and compared it to another popular alternative, whey hydrolysate. It is also the study that most strongly supports hydrolyzed casein.

  It’s nice to know what casein hydrolysate in particular and protein hydrolysate in general means for the speed and extent of amino acid uptake, glycogen recovery, and insulin increase. Ultimately, however, many of us mainly want to know what this effectively does to fat-free mass. Not strange considering few of us are judged on our performance in the 100-meter freestyle, and many are judged on the presence of a six-pack and muscle mass.

  Personal Experience

  The most fun part of writing reviews for Bodyenfitshop is of course receiving the supplements to be reviewed. Because it is not scientifically justified to evaluate the effectiveness of a supplement based on the experiences of one person (what about the other conditions such as rest, nutrition, and training), I mainly evaluate aspects such as ease of use and taste. Of course, I also mention effectiveness if I seem to notice something remarkable, but in this regard, you have more benefit from the numerous studies I have mentioned here. After all, these are conducted among more humans/animals and (mostly) under better controlled conditions.

  Convenience

  PeptoPro® is a very fine powder that dissolves very easily. No hassle with lumps. Because more amino acids are absorbed from it than from normal protein, the required dosage is lower, namely 10-12 grams. This seems very little compared to the doses of 20 to 30 grams of protein that most people will throw into a shake. However, you have to consider what you use PeptoPro® for, namely optimal timing of amino acids. You only use it after training and can choose to mix it with normal protein that is absorbed more slowly and/or carbohydrates to speed up transport.

  Taste

  The latter is also recommended, if only for the taste. As mentioned, DSM found a way to limit the bitter taste following the experience of the Olympic athletes in 2004. I have never drunk Total Recovery Drink, but given the current taste and the fact that it has apparently improved, I can only conclude that it must have been really disgusting back then. If you don’t mix it, it’s not exactly neutral in taste, but very bitter.

  However, this is somewhat of an advantage. DSM could have chosen to add certain flavorings to improve this. However, they have (in my opinion rightly) chosen to leave it in its pure form. You can then decide for yourself whether you accept the taste, or mix it with other products that do contain flavorings (such as normal protein, carbohydrates, or just fruit juice). The taste is not so bad that the more you mix it, the more unpleasantness you have to swallow as was my experience with creatine ethyl ester malate (5 grams in a 500ml shake and you had to drink half a liter with your nose pinched). In my experience, it is not at all so bad that it makes you vomit, as someone on an American forum indicated. Moreover, everything eventually gets used to, especially for athletes and bodybuilders in particular who are used to eating what they should eat instead of what they want to eat.

  What I do take into account is that mixing it with other protein can slow down the rate of absorption. I have no reason for this in terms of studies because as far as I know there are none. In itself not remarkable because there are also very few studies, for example, looking at what happens to the speed of regular whey when you mix it with casein (as in or with milk). I recently described about MCT oil (which leads to faster absorption than fats from longer chains) that absorption is delayed when taken together with fats from longer chains. So I take into account that it can, but I have no reason for it in terms of studies. If you want to play it safe, you take PeptoPro® immediately after training and your other protein half an hour later.

  Price of PeptoPro

  PeptoPro® is, like all hydrolyzed proteins, more expensive than normal protein, but also more expensive than some other hydrolysates.

  You pay at Bodyenfitshop €28.50 for 500 grams. For comparison: For the Whey Hydrolysate from Bodyenfitshop you pay just over €9 for 500 grams (converted, sold per 2kg). For “normal” whey, you pay around €7.70 for 500 grams (converted from 2270 grams). Although I am already comparing with the cheapest prices in the market, it is clear that PeptoPro® is much more expensive.

  There are a few big “buts” here. Firstly, the PeptoPro® at Bodyenfitshop is cheaper than elsewhere. I have put a few next to each other for comparison with prices, possibly converted to 500 grams.

  Various prices PeptoPro® 500 grams (only mentioning “fixed” prices per 11-11-’13 and no offers)

  • Bodyenfitshop       €28.50
  • MDYshop               €56.24 (€44.99 for 400 grams)
  • XXL Nutrition         €29.96€ (€44.95 for 750 grams)
  • Proteinshakes.nl  €33.30 (€49.95 for 750 grams)
  • Bodylab                  Not in assortment
  • Perfectbody.nl       €56.13  (€44.90 for 400 grams, PeptoPro® under MDY label)

  Secondly, as mentioned, you use much less of PeptoPro® daily than of “normal” protein. Although various shops recommend different dosages, the maximum is still 15 grams. This is because proportionally more amino acids are absorbed, so you need to take less of it. Moreover, you only use it after training because then the fast absorption is important. This means for most people that they will use it between 3 and 5 times a week. Even if you take 15 grams as a dose and train five times a week, you will almost do it with a pot of 500 grams for almost 7 weeks. That is longer than most people will do with 2 kilos of whey (often a little longer than a month). Seen in this way, PeptoPro® is actually cheaper than normal whey.

  Here I must emphasize that I do not see PeptoPro® as an alternative to or replacement for “normal” protein because, of course, you also need to provide your body with protein for the rest of the day and many, if not most, cannot achieve this from food alone. It’s nice if PeptoPro® immediately after training ensures more protein synthesis in the muscles and thus more muscle growth. However, for the rest of the day, you also need protein to prevent breakdown. PeptoPro® is therefore more of an addition and with the many choices of supplements, it is questionable whether you see a greater added value in PeptoPro® than in other supplements that must come out of the same limited wallet alongside “normal” protein.

  “But it works”

  Again, what I have personally experienced in terms of muscle growth, strength, etc. is not very interesting as it may not mean much. However, I do want to mention something here.

  I have been using PeptoPro® for about a month during which my diet was downright poor due to circumstances. Apart from the regular shakes in the morning, after training, and before bedtime, I made a bit of a mess of it. Nevertheless, over the past month, I have broken through some plateaus that I had been struggling with for a while.

  For instance, since I started training in a different gym, I couldn’t dip with 80kg between my legs anymore. This was probably due to different distances between the bars of the dipping bar. I was stuck at 70kg and had just managed to reach 75kg again with only a few repetitions. In the past month, however, I have dipped with 80kg three times already, with 4-6 repetitions.

  Additionally, I noticed more ease and energy in other exercises.

  Now, I will be the last one to try a supplement and immediately attribute enormous results to it. I have tried too many supplements with too little results for that. Just because my diet was otherwise so poor, it surprised me that I had still gotten stronger and hadn’t decreased in dry mass.

  I see this experience reflected in other, normally critical, users who report this on forums (52,53). In those same forums, it is often mentioned that people who have difficulty with free amino acids (in the sense that they experience stomach problems), have no trouble digesting PeptoPro®.

  Would I Buy PeptoPro®?

  For this article, I have read many studies that demonstrated the benefits of hydrolyzed proteins over regular protein. However, when it came to the type of hydrolysate, whey or casein, there were only two studies and they contradicted each other.

  In rats, the recovery of glycogen was examined, and whey hydrolysate was found to have the greatest added value compared to glucose, while casein hydrolysate had no added value.

  However, among American police officers, casein hydrolysate was found to lead to significantly more fat burning, muscle mass, and strength than whey hydrolysate.

  Although as a hobby builder, I find the latter more interesting than glycogen storage, I do not find one study convincing enough to determine the difference between the two hydrolysates.

  However, I am convinced of the advantage of hydrolysates in general, given the many studies demonstrating the rapid absorption of di- and tripeptides. However, I am hesitant about whether to buy the cheaper whey hydrolysate, of which the degree of hydrolysis and percentage of di- and tripeptides are not known, or the more expensive PeptoPro®, of which more is known about the degree of hydrolysis. I am currently inclined to choose whey hydrolysate, but that is also the crisis speaking. As a competitive bodybuilder training towards podium performances, I would probably choose PeptoPro®.

  Summary and Conclusion PeptoPro

  The difficulty with evaluating PeptoPro® is that there are very few studies that have specifically used PeptoPro®. Many conclusions have to be drawn from studies conducted with hydrolyzed casein, the comparability of which is questionable. The limited information from DSM itself does not make this any easier. My clearest conclusion is therefore that more research needs to be done, particularly comparing it with other types of protein, especially whey (hydrolysate), and free amino acids.

  That said:

  In terms of molecular weight, you might expect PeptoPro® to lead to faster absorption of amino acids and di- and tripeptides, which would ensure faster and more complete transport of amino acids to the blood. Although some studies contradict this, it seems confirmed given the vast majority of studies that support it and the way they are designed.

  Furthermore, several studies have shown that hydrolyzed protein increases insulin levels in the blood more than non-hydrolyzed protein. Unfortunately, the difference in this between casein hydrolysate and whey hydrolysate has not been studied. More importantly, it is unclear whether this increased rise contributes to extra muscle mass.

  Regarding glycogen replenishment, I have only found one relevant study. This study found that hydrolyzed casein with glucose replenished glycogen slower than whey hydrolysate with glucose and even regular whey with glucose. In fact, there seemed to be no added value of hydrolyzed casein with glucose compared to glucose alone.

  German researchers found that if performance had to be delivered for two consecutive days, performance was better when PeptoPro® was consumed after the exertion on the first day. However, the design of the study was not good and there was no comparison with other types of protein or free amino acids. The same applies to a study showing that endurance increases when PeptoPro® is consumed in between.

  The story becomes much more positive when we look at actual effects on body composition. Both from an animal study and from a study among American police officers, it appeared that hydrolyzed casein lowered body fat more and increased muscle mass more than hydrolyzed whey.

  One of the differences between whey and casein, and thus also between the hydrolysates of both, is the amino acid profile, the degree to which the various amino acids occur in the protein. However, there are no major differences in this (except for proline), especially when it comes to the most important amino acids for muscle growth.

  My personal experience is that PeptoPro® is easy to use. The taste is still very bitter, but easily improved by combining it with other supplements or adding it to fruit juice. My personal experience in terms of effectiveness is very positive even though I did not expect any directly observable results.

  In terms of price, PeptoPro® seems expensive, but considering the size of the doses and the frequency with which you use it, this is not too bad. This also depends on where you buy it and under which label. In some places, PeptoPro® is almost twice as expensive as at Bodyenfitshop.

  I do see an added value for PeptoPro® in my personal supplement arsenal, although I doubt whether whey hydrolysate can’t mean the same at lower costs.

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  51. community.myprotein.com/supplements-formulas/28576-PeptoPro®-my-experience.html
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  53. intensemuscle.com/archive/index.php/t-46143.html