How To Take L-Glutamine For Gut Health - The Ultimate Guide (2023)
If you're sitting at home with your beautiful tub of L-Glutamine in hand and wondering...how do I actually take it...then this is the ultimate guide for you! And that's because we're going to use the latest research to answer your 5 main questions about using a L-Glutamine supplement for gut health. We'll look at whether you should take it with or without food, plus the best time of day to consume it and which drinks to mix it with. Plus we'll even cover how much to use and which glutamine supplement is best for gut health. Let's go!
Table of Contents
Everything you need to know about using L-Glutamine
Glutamine is a remarkable amino acid for gut support. Not only can it help with bloating and digestion, but also leaky gut. In fact, this 2011 meta analysis of 86 different studies on glutamine and gut permeability, found
“Glutamine is considered the most important nutrient for healing of ‘leaky gut syndrome’ because it is the preferred fuel for enterocytes and colonocytes”.
But here’s the thing…
...L-Glutamine in supplement form can be a bit of a primadonna. Meaning, there is a right and wrong way to take it. And if you’ve read a few articles online, you might have seen all sorts of conflicting info on the best way to take L-Glutamine for gut health. At times it can feel about as confusing as watching season 2 of WestWorld!
And if that’s you, then this is the explainer guide you’ve been waiting for. Because here at Essential Stacks we make one of the most popular L-Glutamine supplements in the world, Gut L-Glutamine. And using our years of research in this field I’m going to answer your top 5 questions.
What we'll cover in this guide
- Should you take L-Glutamine with or without Food?
- When is the best time of day to take it?
- What is the best beverage to drink it with?
- How much L-Glutamine should you take?
- And of course which type of L-Glutamine powder is best?
Knowing this will make all the difference. Because if you are taking it incorrectly, you might be wasting your money, or worse…missing out on all the health benefits! Let’s go!
a) Should you take L-Glutamine with or without food?
Well, with most supplements we tend to suggest that you take it with food. And that is because most supplements are better absorbed when eating a meal. For example, vitamin D is a fat soluble vitamin / hormone. And so it is best taken with a meal containing some fat.
Meanwhile, other supplements are usually just better tolerated when taken with food. For example, fish oil tends to be gentler on our GI tract when it is taken with a meal, as opposed to on an empty stomach. Meaning no fishy burps.
But when it comes to gut health supplements things aren’t quite so simple. And these general directions aren’t necessarily the most suitable. For example, probiotics - should you take them with or without food? Well, the answer depends on:
- The probiotic strains being used
- The type of meal being eaten
- The encapsulation technology used
- And a host of other factors
In other words, it’s complicated! So much so we actually create a whole article on when is the best time to take probiotics.
Now for glutamine at least, things are a bit simpler. And it all has to do with absorption. Which I’ll explain now.
Photo: It is best to avoid taking L-Glutamine when eating high protein foods - hello steak dinner!
So the first thing you need to know is that high protein foods like meat and seafood have lots of amino acids in them. And the second thing is that L-Glutamine is ALSO an amino acid. And as you can imagine, our intestinal tract can only absorb so many amino acids at the same time.
Which means by consuming L-Glutamine with protein rich foods, you’re asking your intestinal wall to do too much. It simply won’t be able to absorb ALL the L-glutamine.
And therefore, if we want to give glutamine the best chance of being fully absorbed, it can help to take it WITHOUT proteins. That way we are not forcing our glutamine to compete for absorption like some sort of Amino Acid Hunger Games! So for L-Glutamine we suggest people take it without protein-rich foods.
Now given most meals contain some protein, our general guidance is to take it 1 or more hours before OR after a meal. So for example, if you eat breakfast at 7.30am you might take your L-Glutamine any time before 6.30am or any time after 8.30am.
b) When is the best time of day to take L-Glutamine for gut health?
Now in terms of the best time of day to take L-Glutamine, well, this is where things get simple! You see, while other supplements often need to be taken at specific times of day - hello magnesium my sleepy friend.
It doesn’t really matter when you take L-Glutamine.
With that said, taking it first thing in the morning is usually best as it is easy to remember, helps with compliance and gives your gut a great headstart for the day.
Photo: L-Glutamine is best taken away from food, generally first thing in the morning when you wake up.
Also, many people may opt to take L-Glutamine twice a day to give their gut extra support. And if that’s you, then it can be best to split your glutamine between the morning and early evening.
For example, you might take it first thing in the morning when you wake up…and then your second serving sometime before dinner.
a) What beverages can glutamine be mixed with?
When it comes to the best beverage to take your L-Glutamine with things get a little more complex. For example, should you go full Kim Kardashian and add it to your kale-spinach-blueberry smoothie? Or should you add it to your precious life-restoring morning coffee?
Well don’t worry, because I’ll explain now exactly which beverages glutamine goes best with, and which ones you should avoid.
But before I do, our research team found an interesting 2020 research piece from the CDC, showcasing the most consumed non-alcoholic beverages in America.
Water accounted for 51.2% of total nonalcoholic beverage consumption among adults on a given day in 2015–2018, followed by coffee (14.9%), sweetened beverages (10.2%), tea (8.7%), fruit beverages (5.6%), milk (5.5%), and diet beverages (3.8%).
And as a quick pop quiz how many of these beverages do you think would be okay to consume with L-Glutamine?
Obviously water would be fine. But what about the other 6 types of beverages?
Well, it turns out only 3 of the other beverages would be okay. And to find out why, let’s look at the 2 most important rules for choosing a suitable drink for your L-Glutamine.
b) Hot versus cold beverages
So first of all, in terms of hot versus cold drinks it is best to take L-Glutamine with cold or room temperature drinks. And that is because research as far back as the 1980s has shown amino acids like L-Glutamine, tend to only be stable up to 120 degrees fahrenheit or 49 degrees celsius.
Meaning, above these temperatures, heat can denature or damage the precious amino acids, including those in your L-Glutamine supplement.
You see, while your L-Glutamine will do fine in your body, which sits at a temperature of around 98.5 fahrenheit or 37 celsius, they might struggle in something like coffee or tea, which are usually consumed at 180 fahrenheit or 82 celsius.
By the same token, avoid mixing L-Glutamine with any gut nourishing broths like bone broth or even soups like miso.
c) Protein-based beverages
Next up, it is best to take L-Glutamine with drinks that do NOT contain lots of other amino acids. And this is because like taking it with foods, we don’t want our glutamine having to compete with them for uptake and absorption in your GI tract.
Now unless you moonlight as some sort of food chemist, you might not know which drinks contain significant levels of amino acids. Thankfully though our team at Essential Stacks have done the research for you. And we actually did some light reading of this book on Infrared Spectroscopy for Food Quality Analysis and boy what a page turner it was…move over Stephen King!
Anyways, the main drinks we found that are high in amino acids were:
- Protein rich beverages like milk
- As well as protein powder drinks
- And of course, sports recovery drinks that pack extra amino acids into them.
And although we found some fruit juices like orange juice may contain 0.3% amino acids, most contain almost none, meaning they are not a high source of amino acids.
So now you know cold drinks without too many amino acids are ideal let's look at the best drinks to mix your L-Glutamine with, in order from most ideal to least…
Photo: L-Glutamine powder is best taken with water, but you can also take it with other drinks, which we cover below
7 best drinks to mix L-Glutamine with (ranked from best to worst)
- So first up water. It is the perfect delivery vehicle for your precious amino acids and it is without doubt our favorite beverage for glutamine. Our suggested use directions are to mix 1 scoop or 5 grams of L-Glutamine powder, with 8 fluid ounces or 240 mils of water. Of course, if you don’t love the light naturally fermented flavor of glutamine, then you can mix it with flavored beverages and I’ll run through them now.
- So the best flavored beverage would be homemade flavored water. In other words, you can infuse or squeeze fruits like lemon, lime or berry into your water. And yes I know this sounds really hippy…like something Gwyneth Paltrow might force you to drink on the beaches of Malibu…but this is the next best thing after plain ol’ water.
- The next best beverage to mix your glutamine with would be vegetable juice such as tomato juice, beet juice, or if the self loathing is strong you could even try taking it with green juice!
- Now understandably if that doesn’t have you salivating to try glutamine, then you can try taking it with low sugar fruit juice or fruit juice diluted with water. This is a great way to enjoy some flavor, without too much sugar. And whether you go for apple juice, freshly squeezed orange juice or even low sugar coconut water, as long as you dilute it enough, you’ll enjoy a gut nourishing and glutamine rich drink.
- Now, another great option would be lightly sweetened homemade ice tea. Which tastes so refreshing, especially in summer.
- Or even another type of cold tea, being kombucha. Which is a fermented black & green tea drink.
- You can of course, also try mixing your L-Glutamine into a protein & dairy free fruit smoothie. Which is always going to taste great.
So as you can see…you have a lot of options for drinking your glutamine.
How much L-Glutamine per day?
Well, this is an extremely complicated question to answer, since there is no recommended dose from the FDA for gut health support.
So to answer this question, our research team at Essential Stacks had to dive into the scientific literature, as well as gather consensus opinion from functional health experts in the space.
Photo: We designed our L-Glutamine powder to be taken in a serving size of 5 grams and you'll find a scoop in each container to measure this precisely. If you haven't tried it yet, you can buy it on Amazon or direct from us
And we actually created a whole article on L-Glutamine dosage. But if you just want the quick answer here’s a short extract from that article:
We believe 5 to 10 grams of L-Glutamine 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.
4) Buyer's guide
L-Glutamine capsules vs L-Glutamine powder supplements
Photo: L-Glutamine capsules are convenient, since you can take them without mixing up a drink. But you might need to take quite a few to get your ideal dose of 5 grams for gut support. So we tend to prefer L-Glutamine in powder form.
In terms of which type of L-Glutamine supplement is best to take, well, you can either look for L-Glutamine in capsule or powder form.
The powder form will be more convenient to take, since 1 scoop of powder mixed in a drink is easier to consume than 5 to 10 capsules.
Best L-Glutamine powder - 5 things to look for
When it comes to L-Glutamine powders, there are 5 main things to look for in a high quality supplement…
- The first thing would be that it contains no competing amino acids or other ingredients. Which means you only want to see 1 ingredient on the Supplements Facts panel, being L-Glutamine. And zero other ingredients.
- Next up, make sure it offers 5 g of glutamine per serving, as this is the IDEAL amount for gut support, as we just saw before.
- Obviously, check that it is free of allergens like gluten, dairy and soy.
- Even better, find one that has been independently 3rd party tested for this.
- Contains no animal products and is vegan friendly.
- And lastly, but perhaps most importantly, you should make sure your L-Glutamine is made in the USA. And that’s really important, since MOST glutamine supplements are actually made overseas - commonly in China or Brazil - where quality standards can vary. And the easiest way to tell where a glutamine supplement comes from is to look on the label or on the company’s website: do they mention something along the lines of "Proudly made in USA" or is the company silent on country of origin? If it is silent, chances are it comes from overseas.
Photo: Whether you buy our L-Glutamine or another company's, make sure it ticks these 6 boxes
Now, while most L-Glutamine supplements struggle to meet these standards our very popular Gut L-Glutamine, which we make here at Essential Stacks, of course meets and exceeds these quality standards. And that’s why it has become one of the most popular premium L-Glutamine supplements on the market.
So to wrap up this article, let’s take a quick look at this summary table on how to best take L-Glutamine.
With or without food?
Without protein-rich foods
1+ hours before OR after eating
Best time of day?
Any time - as long as away from food
First thing in morning is best for compliance & head-start for your gut
Best beverage to drink it with?
Any cold beverage that does not contain significant protein / amino acids
E.g. water, homemade flavored water, vegetable or fruit juice, ice tea etc
How much L-Glutamine?
For gut support
Which L-Glutamine powder?
Powder easier than capsules
As you can see, we should take it WITHOUT protein-rich food. Either 1 or more hours before OR after eating. We can take it any time of day, but first thing in the morning is often the easiest to remember and helps with daily compliance and gives your gut a great head-start on the day.
In terms of beverages to take it with, water is best. But other cold drinks that don’t contain competing amino acids like flavored water or low sugar juices can also work.
Meanwhile, 5 grams taken once or twice a day is an ideal amount of glutamine to support your gut. And finally, as we just saw, the best type of L-Glutamine supplement is a powder that meets the 6 quality standards above.
Now we want to hear from you…
What’s your favorite beverage for L-Glutamine?
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
- Weder JK, Sohns S. Model studies on the heating of food proteins. Amino acid composition of lysozyme, ribonuclease and insulin after dry heating. Z Lebensm Unters Forsch. 1983;176(6):421-5. doi: 10.1007/BF01042554. PMID: 6412475.
- Martin CB, Wambogo EA, Ahluwalia N, Ogden CL. Nonalcoholic beverage consumption among adults: United States. 2015–2018. NCHS Data Brief, no 376. Hyattsville, MD: National Center for Health Statistics. 2020.
- Lenders CM, Liu S, Wilmore DW, Sampson L, Dougherty LW, Spiegelman D, Willett WCEvaluation of a novel food composition database that includes glutamine and other amino acids derived from gene sequencing dataEur J Clin Nutr.(2009 Dec)
- Michael Gleeson, Dosing and Efficacy of Glutamine Supplementation in Human Exercise and Sport Training, The Journal of Nutrition, 2008; 138: 2045S–2049S.
- Ziegler TR, Benfell K, Smith RJ, Young LS, Brown E, Ferrari-Baliviera E, Lowe DK, Wilmore DW. Safety and metabolic effects of L-glutamine administration in humans. JPEN J Parenter Enteral Nutr. 1990 Jul-Aug;14(4 Suppl):137S-146S.