Dear Lyle,
I’ve read a number of differing opinions as to the correct amount of glutamine to take, anywhere from 2 grams a day to 15 grams a day. Some opinions are that more then 2 grams a day lowers growth hormone production, whereas other opinions are that anything less then 15 grams consumed at once won’t even have an effect. What is the scoop? How much should I take and when should I take it?
A: Glutamine is an odd compound to say the least. There’s no doubt that it is involved in many processes in the body including immune system modulation and potentially muscle growth. The problem is that most oral glutamine tends to get used by the intestines and very little gets into the bloodstream and into the muscles (this is called the glutamine paradox).
To get around the glutamine paradox, you have two options.
- Megadose: I imagine this is the idea behind the 15 gram number you have. The idea is that if you put enough glutamine into the system at once, some of it will get into the bloodstream (and to the muscles) because not all of it will be used by the intestines. Along these lines Dan Duchaine has recommended dosing l-glutamine right after training in high dosese to replace any glutamine lost from the muscles (glutamine, along with alanine are used to make glucose in the kidney and liver respectively). The problem with this approach is that it’s a very cost ineffective way to do things. You’re using a TON of glutamine but only a little is getting into the bloodstream and to the muscles where you want it.
- Take small doses throughout the day: a study a year or two ago found that 2 grams of oral glutamine, raised growth hormone and did get into the bloodstream. The researchers posited that the small doseage used prevented the intestine/liver from going into ‘absorb all glutamine’ (sounds like a cool sci-fi movie) mode. An interesting (and unanswered) question is how much glutamine you could consume without activating uptake by the intestines/liver. In my mind, if you’re discplined enough to do it, this strategy makes more sense to me. So instead of taking 15 grams of glutamine at once, and only getting some portion of it into the bloodstream (and I’m not sure how much makes it), take 2-3 grams multiple times throughout the day (at least one doseage would be before training and another immediateley after in your post-workout drink) perhaps with each meal. This might allow better uptake and absorption while minimizing cost.
FWIW, my training partner was given some l-glutamine mixed in DMSO (thae solvent that carries anyting you put in it through the skin and into the bloodstrem) by a chiropractor friend of his and swears it helped his recovery when he rubbed it directly onto the bodypart he had just trained. Just FYI.
About the author
Lyle McDonald+ is the author of the Ketogenic Diet as well as the Rapid Fat Loss Handbook and the Guide to Flexible Dieting. He has been interested in all aspects of human performance physiology since becoming involved in competitive sports as a teenager. Pursuing a degree in Physiological Sciences from UCLA, he has devoted nearly 20 years of his life to studying human physiology and the science, art and practice of human performance, muscle gain, fat loss and body recomposition.