L-Glutamine: Stop Getting Sick

 

L-Glutamine is viewed increasingly as a potential tool to perhaps buffer the immune system under times of stress. There's not a ton of evidence, however, in terms of what's in the scientific literature supporting this and other statements, there is some and perhaps enough to maybe experiment with it.

L-Glutamine can be converted into many things. It can be an amino acid, it can be converted into intermediates that are used by mitochondria in the gut epithelial cells as an easy source of energy, and it can be converted into glutamate, a neurotransmitter. It turns out L-Glutamine is essential for the activation of immune cells. So there's a lot of pathways and different fates for L-Glutamine.

But these are all animal studies, so take the findings with a grain of salt. Animal studies are really important for understanding the mechanism behind why things work... but we need human studies as well. Looking at the totality of evidence is important, but remember it's the human studies that we're lacking.

In the literature, I came across one report where endurance athletes – people whose energetic expenditure was at a really high rate - who were experiencing a higher amount of respiratory tract infections, began taking a higher dose of L-Glutamine... like 30 grams... which resulted in a lower incidence of respiratory tract infections.

So I started using it myself as an experiment. I never used to get sick. Then all of a sudden I was getting sick three times a year... which was extremely concerning. So I started taking L-Glutamine.

Now, I take only 5 grams on a daily basis. But if my son is sick, if I have any excessive exposure or stress during cold season, or if I'm traveling a lot, I sometimes take up to 15 or even 20 grams... but not all at once, because it can be a little hard on the gut. So I don't do it all at once. I usually take it only 5 grams at a time. As a caveat, I also take a lot of creatine monohydrate as well. I don't know which one is impacting me most... or both.

But the net effect is that I really don't get sick anymore on this regimen... even if it's brought home to my house, I'm not getting sick. And maybe it's a placebo, but that's okay because a placebo works as long as I'm not getting sick.

I do think L-Glutamine is not something that I would feel comfortable recommending, because there's not a lot of evidence. But I do have confidence that it's improving gut health and it's improving immunity. It's going to help give your immune cells energy... particularly if they need to be activated upon exposure to any pathogen. But I would recommend that it's worth experimenting with. I'm not a medical physician. This is not a prescription. It's just my opinion. If I had cancer I probably would stop taking it, but I don't think it's going to cause cancer.

by Dr. Rhonda Patrick on YouTube @FoundMyFitnessClips on May 15, 2026