How Much L-Glutamine Per Day? (L-Glutamine Dosage Guide)
L-Glutamine has been used by athletes and bodybuilders like Arnold for decades. But more recently, it has become one of the most popular supplements for people looking to support their gut health. Which is not surprising, since glutamine is the preferred fuel source of the cells lining your intestines. In other words, it is like protein powder for the gut or like spinach for Popeye - and can help it stay strong. Now one of the most popular questions we get here at Essential Stacks since we make one of the most popular L-Glutamine supplements is "How much L-Glutamine should you take per day?". And that's exactly what we'll answer in this ultimate guide to L-Glutamine dosage!
Table of Contents
So here’s the thing: if you are some crazy athlete or bodybuilder like Arnold or even Dwayne ‘The Rock’ Johnson and train like an animal, you might just want to mix an entire tub of glutamine into your morning smoothie…just kidding!
But what about the rest of us looking for gut support? How much glutamine should we take to support our digestive health? Let’s find out!
1. How much L-Glutamine is recommended?
Now the important thing for us to know is that there is no general recommended intake of glutamine per day. So while you might Google “daily recommended intake of Vitamin C" and get a clear answer:
- Men should take 90mg of vitamin C a day
- And women 75mg of vitamin C a day
You are not going to find the same thing for glutamine.
And that’s not surprising, given that the FDA has only issued daily intake targets for macronutrients like protein and fat, as well as vitamins like vitamin C and minerals like zinc.
So without any official guidelines in place, it means we have to go on a bit of a journey to work out the optimal range. And the good news of course, is that our research team at Essential Stacks has done all this hard work for you.
So to explain our answer to this question, we’re going to cover 4 things in the remainder of this article:
- First, we’ll look at how much glutamine we already get through our diet. This way we can see where our existing intake levels are.
- Then, we’ll look at whether this is enough glutamine by itself. That way we can see whether a glutamine supplement is actually necessary.
- Next, we’ll look at what supplemental l-glutamine dosages have been studied to be safe. That way we can establish a maximum dosage amount.
- Finally, we’ll look at what amounts of L-Glutamine health experts recommend for people looking to support their gut health. This will of course give us a better idea of the ideal amount, as opposed to the maximum tolerable amount.
And obviously, none of this is medical advice. So if you want to find the precise dose that works for you, please talk with your healthcare professional.
2. How much L-Glutamine do we get through diet?
Well, since L-Glutamine is an amino acid, it is found in protein-rich foods like beef, chicken, eggs and salmon. And while some plant based foods like spinach, nuts and lentils, may also contain some glutamine, it is minor by comparison.
This means unless you’re vegan, you are probably getting a decent amount of glutamine through your diet.
Unfortunately, it is hard to calculate the exact amount. You see, while food tracking apps may give you data on the basic macros like protein, fat and carbs, they are not so forthcoming with glutamine data. And so that’s why our research team had to dive into the scientific literature on this topic.
And when we looked through studies analyzing how much glutamine you’re likely getting through your food we found 2 interesting data points.
- First, a 2000 study by Harvard Medical School. They estimated that 4 to 8% of the amino acids in food proteins were in the form of glutamine. Of course, that type of geek speak doesn’t really help us. But thankfully, they also crunched these numbers to discover what that meant in terms of grams of glutamine per day. And by their calculations it meant “less than 10 g of dietary glutamine is likely to be consumed daily by the average person.”
- By contrast, in this 2008 research piece published in the Journal of Nutrition, the researchers revealed: “the normal daily intake of glutamine from dietary protein is 3 to 6 grams per day”. This was based on the idea that the average 70 kilogram individual will eat 0.8 to 1.6 grams of protein per kilogram of body weight per day.
So we can conclude from these 2 studies that the typical person will get anywhere from 3 to 10 grams of L-Glutamine a day from their diet, depending of course on how much protein-rich food they eat.
With that said, if you’re an athlete like The Rock, and eat a lot more, including a lot more protein - they will consume more glutamine than us. So their daily intake may be well in excess of 10 grams.
3. Is 3 to 10 grams of L-Glutamine enough?
So for most people it may well be enough to fuel their body, in particular their intestinal health. But as this research study published in Nutrition Reviews put it:
"During stress the body's requirements for glutamine appear to exceed the individual's ability to produce sufficient amounts of this amino acid.”
Which means for those of us who are exercising hard, experiencing stress, inflammation or immune system issues, or most commonly, poor gut health: well, then the 3 to 10 grams of glutamine you get through your diet, may not be enough.
And in these situations extra L-Glutamine, in supplement form, can be very helpful. But the big question of course is how much?
4. How much L-Glutamine is safe?
Well, as a starting point to working this out, let’s answer the question how much L-Glutamine is safe? In other words, what amounts have been studied and shown to be tolerable.
So in the 2008 research piece published in the Journal of Nutrition, which we looked at before, researchers concluded that:
"...intakes of glutamine of approximately 20-30 grams seem to be without ill effect in healthy adult humans.”
They also found:
“Doses of up to 0.65 grams per kilogram body mass of glutamine have been reported to be tolerated”
So if for example you are a 125-pound female, which is equivalent to 56.7 kilograms, it translates to roughly 37 grams of glutamine per day.
While for say a 175-pound male, which is equivalent to 79.4 kilos, it translates to roughly 52 grams of glutamine per day.
In other words, researchers found supplemental L-Glutamine can be tolerated even when taken in high doses.
Other studies have supported this, such as this 2020 study published in Nutrients. While other studies have suggested the maximum tolerable amount is a bit less, with this one suggesting it is just under 40 grams per day.
Probably even more interesting for us though, is that the FDA has in fact approved L-Glutamine at levels of 30 grams a day for both short bowel syndrome and sickle cell.
And what we can draw from that, is glutamine is seen as tolerable and safe at these levels.
Now with all of that said, before you go out and start taking 30 grams of glutamine a day, it’s important to remember what your health goals are.
Because for most of you who are not suffering from issues like short bowel syndrome, and are instead simply looking to support your gut health, you will likely be fine using a much smaller amount per day.
Not only will this be easier for you to consume, but it will also save you a lot of money.
5. How much L-Glutamine do experts recommend?
Well, the first place we wanted to show you is Examine.com.
And that’s because they are a supplement research group, with no actual ties to supplement products. And because of this, they are one of the most trusted expert voices in the dietary supplements world.
So if we look at their research piece on L-Glutamine supplements, we can see they recommend supplementation of L-Glutamine tends to be dosed at 5g or above.
And as they clarify further down this is sufficient for intestinal health reasons, meaning gut health support.
In other words, Examine suggests 5 grams or higher for people looking to support their gut health.
Next up, let’s look at what another leading expert voice in the nutritional sciences space has to say. Specifically, Dr Dominic D'Agostino, who you might have seen in a TED video, or several times on the Tim Ferriss podcast or even on Youtube.
In fact, when Dr D'Agostino talked with Dr Rhonda Patrick about the optimal dose of glutamine for gut health, he stated:
"The gut's going to be very greedy when it comes to glutamine. So I think just maybe 5 or 10 grams of glutamine to help repair your gut. We know that if your gut permeability is impaired, that can wreak havoc in your body as far as systemic inflammation."
So hopefully we start to get a good picture of how much glutamine per day makes sense for general gut support, especially for the intestinal lining.
And that number might be anywhere from 5 to 10 grams per day, depending on the individual.
The big takeaway here is that the serving size is at least 5 grams per day, which means 2 things:
- L-Glutamine in capsule form is probably not ideal, since you would have to swallow 8-10 capsules a day to hit just 5 grams. And even more if trying to take in 10 grams.
- Secondly, so-called 'Leaky gut supplements' that include glutamine, along with many other ingredients such as slippery elm and marshmallow root - typically only deliver just 1-2 grams of glutamine per serve. Which means they are arguably underdosing the main ingredient for intestinal health, being the glutamine itself.
All of this is to say, if your goal is to support your gut health, then your best bet is likely an L-Glutamine supplement in powder form.
6. What is the suggested use of L-Glutamine?
So now we get to the final part of this article, and look at the question: what is the suggested use amount for glutamine? Or in other words, how much do we, at Essential Stacks, believe is the optimal amount of glutamine?
And of course, this is not a recommended dose, as that is something only your healthcare practitioner can give you, but rather a suggested use direction.
Well, if you look on the back of the label of our Gut L-Glutamine - no surprises, we actually have the same serving size suggestion in line with the research carried out by both Examine and Dr Dagastino.
As you can see, it is 1 scoop of L-Glutamine powder, which is 5 grams - taken 1 to 2 times a day. Meaning 5 to 10 grams a day.
7. Our conclusion
So to sum everything up: we believe 5 to 10 grams per day is the optimal serving size for glutamine if you’re looking to support your gut health. And that’s because it delivers enough glutamine to feed and nurture your GI tract, but not too much to run the risk of tolerance issues popping up.
So if you’re looking to make glutamine a part of your daily supplement protocol, 5 to 10 grams - which is also in line with expert consensus - is the optimal amount.
Now that you know how much glutamine can make sense for gut health, you might find it interesting to learn How to take L-Glutamine, including with or without food, and to also know which drinks to mix it into.
For all of that check out the article we did on How to take glutamine.
And of course, if you would like to - you can try our L-Glutamine powder, which is made right here in the USA and 3rd party tested.
Now we want to hear from you:
How much L-Glutamine do you take and why?
Let everyone know by leaving a comment below.
An evidence hierarchy is followed to ensure conclusions are formed off of the most up-to-date and well-designed studies available. We aim to reference studies conducted within the past five years when possible.
- Systematic review or meta-analysis of randomized controlled trials
- Randomized controlled trials
- Controlled trials without randomization
- Case-control (retrospective) and cohort (prospective) studies
- A systematic review of descriptive, qualitative, or mixed-method studies
- A single descriptive, qualitative, or mixed-method study
- Studies without controls, case reports, and case series
- Animal research
- In vitro research