Advanced Supplement Guide 1: PeptoPro®

Peptopro is a product that has been around for a few years now, and with recent research showing that complete protein sources may be more beneficial for promoting muscle growth than their branch chain or essential amino acid supplement cousins, it is a supplement that is increasing in popularity as part of many peoples peri-workout nutrition.


When we talk about peri-workout nutrition we are fundamentally talking about the periods in and around our training, including pre, intra and post workout.  During resistancetraining it has been shown that complete protein sources have positive effects on supporting protein synthesis and preventing muscle protein breakdown, helping to support muscle growth. However there is conflicting information about what protein sources are best during these periods and this stems from research focussing on different feeding strategies at different times. For example, if we look at whey supplementation as a post-workout supplement there is plenty of evidence to suggest that this promotes muscle growth compared to other protein sources due to acute elevations in our protein synthesis. However the idea of an ‘anabolic window’ is still debated because the influence of protein intake before training is not taken into consideration with some studies showing that supplementation before training has a comparable effect and this might also be influenced by the protein source… this may mean there is some form of anabolic window but this might stretch further in both the pre and especially the post-training window than is often reported (Tipton et al., 2005 & 2007).  It has also been suggested that this requirement for feeding within a window might be dependent on several factors such a person age, and their training experience (Tipton and Phillips, 2011).


I guess what I’m trying to say is that fundamentally stimulation of muscle growth from training will require feeding consistently throughout the day with quality, whole food protein sources, however there might be some benefit in targeting windows in and around training that might make some differences. I also think that in those who have inconsistent eating patterns that they can make up for SOME of their nutritional short falls by really targeting their nutrition in and around training.  For those of us wanting to guarantee the best possible approach, there is a trade-off between using supplements that might offer us some benefit (no matter how small) versus the high cost of some supplements. PeptoPro is one of those supplements that might give you the '1%' you need each day or week, which over time adds up to help build the physique you want. Whether that is important to you, is something that only you can decide and as a product it certainly won’t make up for poor nutritional habits. So now we’ve set the scene, let’s take a look at what PeptoPro is and how it can be beneficial.


PeptoPro is manufactured from casein which is known typically as a slow digesting and slow release protein, which through a process called hydrolysis is broken down from full chains of amino acids that make up the casein proteins into smaller di and tri peptides. Di and tripeptides are chains of two and three amino acids and this makes them require virtually no digestion and are small enough that they can absorbed rapidly into the blood stream to be delivered to the muscle. Obviously coming from a complete protein source this provides all the amino acids required to build muscle and it is also highly soluble in water which means it is easy to drink and it doesn’t ‘feel’ like a conventional protein shake. It is for these reasons that PeptoPro is gathering popularity, particularly as an intra-workout supplement.


So is there any benefit to using PeptoPro over other whey supplements?  Pennings et al. (2011) showed little difference between whey and hydrolysed casein in terms of insulin response and provision of essential amino acids in older men during periods of inactivity, however leucine appearance was quicker in whey which generated an increase protein synthetic response (meaning more protein was being made). However a study on chronic obstructive pulmonary disease patients showed that hydrolysed casein generated more protein synthesis than whey, but whey reduced protein breakdown leading to a comparable effect on net protein balance (Jonker et al., 2014). From the limited studies that are (let’s be honest) not very applicable to a healthy, active population and timed around training, it is difficult to draw meaningful conclusion as to which is better, but it is likely that both will have positive effects on muscle growth as they are complete proteins that support anabolism.  This means that PeptoPro offers many comparable benefits to whey but it cannot be considered ‘better’ in these regards with the current data.


In summary hydrolysed casein may offer greater benefits than branch chain amino acid formulations as an intra workout supplement due to provision of a complete amino acid profile. In comparison with whey, from an anabolic perspective it appears to have similar benefits. One possible advantage of hydrolysed casein over certain types of whey is the reduction in lactose sugars and other potential allergens, making it suitable for those with intolerances and dietary sensitivities. There is certainly evidence that in isolation PeptoPro is an effective muscle building tool, however more research in healthy, resistance trained, people needs to be performed across the board with different proteins at different timings to truly elucidate their benefits and to guide our understanding on how to optimise our peri-workout nutrition and supplementation.

Dr P.



Jonker, R. Deutz, N., Erbland, M., et al. (2104) Hydrolyzed casein and whey protein meals comparably stimulate net whole-body protein synthesis in COPD patients with nutritional depletion without an additional effect of leucine co-ingestion. Clinical Nutrition. 33: 211-220.

Pennings B, Boirie Y, Senden JM, et al. (2011) Whey protein stimulates postprandial muscle protein accretion more effectively than do casein and casein hydrolysate in older men. Am J Clin Nutr. 93:997–1005.

Tipton KD, Elliott TA, Cree MG, et al. (2007) Stimulation of net muscle protein synthesis by whey protein ingestion before and after exercise. Am J Physiol Endocrinol Metab. 292:E71–E76.

Tipton KD, Rasmussen BB, Miller SL, et al (2001) Timing of amino acid-carbohydrate ingestion alters anabolic response of muscle to resistance exercise. Am J Physiol Endocrinol Metab. 281:E197–E206.

Tipton, K.D. and Phillips, S.M. (2011) Dietary Protein for Muscle Hypertrophy. Nestlé Nutr Inst Workshop Ser: 76:73–84.