How Much Leucine Is In 1 Serving of Mag-10?


I thought that there was a thread on this forum where Chris mentioned that a serving of Mag-10 had 5 grams of leucine, but I can’t find it. The label describes di- and tri-peptides from hydrolyzed bioactive casien, but “regular” hydrolyzed casien would not have 5 grams of leucine per 20 grams of total amino acids (regular hydrolyzed casien only gets about 8% of it’s amino acid content from leucine which would be about 1.5 grams per 20 gram serving).

With BCAA structured peptides, the leucine content is on the label, and there is an explanation of how the leucine content is bumped up.

I want to be sure that a serving of Mag-10 has enough leucine to spike levels (somewhere around 5 grams). Can that be confirmed? and if so, why not put it on the label since it would be a major selling point setting it apart from other hydrolyzed casien products that only contain small amounts of leucine.

I want to know this primarily because I also use BCAA structured peptides, and if Mag-10 is not around 5 grams of leucine per serving I might bump up the leucine accordingly for days that I pulse feast.

As a side question, is the protein in Plazma the same amino acid/peptide breakdown as in Mag-10?


I see a conversation here Leucine Content and adding leucine is not recommended. I am pretty sure that one of the contributors did write that Mag-10 had 5 grams of leucine per serving though, but what this conversation shows is that Surge has 5, and that Mag-10 is “better”.


I’m not sure I said that, because I don’t know that. I did say in the other thread that Surge Workout Fuel has 5g, as listed on its label.

Spike levels of what? Mag-10 was designed to be a fast-absorbing, highly efficient protein source. The combination of protein and carbs in its formula achieve that goal.

Plenty of people have done the pulse feast with textbook guidelines, using “just” Mag-10 and no added leucine. If you want to experiment, go for it, but it works perfectly fine as-is.

As I’ve mentioned before, questions about product label info is best handled by shooting an e-mail directly to Biotest Customer Service ( or giving them a call (800-525-1940).

I believe they use the same protein.


Spike levels of Leucine. There is a lot going around in sports nutrition circles that you need estimated amounts ranging from 3.5-5.0 grams of in one leucine pulse to maximally activate mTOR. The term “leucine pulse” is now common in various journals of metabolism, endocrinology and physiology and most of the research points to the 3.5-5.0 gram range, though speed of absorption may make up for some of that.

Since Mag-10 has been featured in articles about “protein pulsing” and protein pulsing basically is derived from research on leucine pulsing, it looks at face value like Mag-10 is intended (at least in part) as a way to spike leucine levels to get the mTOR activation effect. In fact, I would submit that protein pulsing is only effective because of the spike in leucine levels and without somewhere near that 5 gram level there is some empirical evidence that the spike in leucine levels are not optimal. Hydrolyzed casien and whey both tend to be about 10% leucine by amino acid unit, so I’d expect that a serving of hydrolyzed casien with 20 grams of protein would have around 2 grams of leucine.

If you were to search the internet now for leucine 5 grams, or leucine how much, you would see a bunch of newer stuff posted within the last 6 years pretty much universally calling for a 5 gram bolus of leucine to maximize mTOR activation.

I’d like to add that I really appreciate the having the Mag-10 formula available. Most hydrolyzed casien and whey are only partially hydrolyzed to produce some degree of pre-digestion. This also results in mild allergic response from me since there are still large milk proteins present in normal hydrolyzed milk proteins (I get sinus congestion) but I get no congestion from Mag-10 or Plazma and I attribute that to a greater degree of hydrolysis, down to di- and tri-peptide levels. I also can afford as much as would be beneficial for me so I would be fine with taking larger doses but taking leucine levels above 5 grams per dose just takes longer to clear out, so MORE is not necessarily better. I also have BCAA structured peptides which gets about 25% of its amino acids from leucine, and is also at least 90% hydrolyzed to di- and tri-peptides (based on the label description). Unfortunately, Metabolic drive will cause some sinus inflammation for me, probably due to the larger polypeptides that still retain the ability to cause sensitivities.


This early article on “Pulse Fasting” says that Mag-10 is “spiked” with leucine, suggesting to me that it is not just casein hydrolysate, but that it has undergone a process similar to BCAA structured peptides that enhances the leucine content by cutting polypeptides at certain spots and filtering certain sizes.

Granted, the article was from 2010, and I didn’t start seeing people put empirical numbers on the leucine needed to produce a pulsing effect until early 2013, where studies showed that “as little as 2.5 grams of leucine could activate protein synthesis.” Later studies arrived at optimal levels ranging from 3.75 to 5.0, the later one playing it “on the safe side”.

Many of the early studies also used a standard dose of 25 grams of whey isolate, which would have just about 2.5 grams of leucine. Whey isolate should be somewhat slower to spike leucine levels than hydrolysate, which should also be slower than a di- and tri-peptide formulation (current research shows that the blood largely transports di- and tri-peptides, not needing to have them broken down to single amino acids, and di- and tri-peptides actually absorb even faster than individual amino acids). The fast absorption could get the leucine level up faster allowing a smaller dose to work, which would be great because it would allow more frequent pulsing. Here

you can see that 25 grams of mere whey isolate maximizes total amino acid concentration in the blood at 60 minutes with levels about 3/4 of the way to baseline by 3 hours. (Other research shows that amino acids from a normal meal typically clear completely in 4 hours-protein mildly raises insulin levels for 4 hours). Mag-10 should raise the levels faster though would not likely be faster than mono- and di-saccharides which peak in the blood at about 30 minutes. More recent work has strongly suggested that it is the leucine levels, and not the total amino acid levels that turn on protein synthesis, so plausibly, someone could consume low leucine protein throughout the day to prevent catabolism, but still pulse leucine levels over the levels of total amino acids with a high leucine source. Anyway, as of this time, a nutritional protocol should only be called “pulsing” (a term that now has a specific meaning in published research) if it provides at least 2.5 grams of leucine-the minimum amount shown in literature to produce a pulsing effect-or if research demonstrates a leucine spike on a lower dose with a faster absorbing product like Mag-10.