L-Glutamine and Creatine Together

Quick answer

No source we read says L-glutamine and creatine interfere. In one 8-week trial of 29 athletes, creatine with 4 g of glutamine a day beat placebo, but the report does not show glutamine adding to creatine. Creatine has strong grades for strength, while glutamine's are early and untested near the 3.15 g in our scoop.^1,2,3

Key facts

Glutamine is not among the three amino acids the body uses to make creatine, which are glycine, arginine and methionine.⁴
In an 8-week trial of 29 athletes, creatine with 4 g of glutamine a day and creatine alone each beat placebo for lean mass, with no added gain from the glutamine described.¹
The trials with positive results for glutamine used about 15 g or more at a time, mostly in people under medical care or in extreme exercise.^3,5
In a 6-week resistance training trial, almost 45 g of glutamine a day added no strength or lean mass over placebo.⁶
A position review places glutamine in the little to no evidence group for muscle building and performance.⁷

Two amino acid supplements with different stories

The liver and kidneys make about 1 g of creatine a day from three amino acids: glycine, arginine and methionine.⁴

Adults take in about 3 to 6 g of glutamine a day from protein foods, and the body makes more.^3,8

So glutamine is not an ingredient in creatine, and the body does not need a glutamine supplement to make it. The body makes glutamine itself, mainly from the BCAAs, and it is the most abundant amino acid in muscle and blood. What the two have in common is shelf space and the sports trials that tested them, not a shared pathway.^3,4

How the evidence grades compare

This is a lopsided pair. Creatine has a deep trial record behind it, and glutamine's two claims are graded early because the fuel role is established physiology while a benefit from a supplement has not been shown at everyday amounts.^2,9

Supports muscle strength during resistance training*^2,4,10

Strong evidence

A 2025 meta-analysis of 69 randomized trials (1,937 people) found that creatine plus resistance training added about 1.4 kg to bench or chest press and 5.6 kg to squat strength over placebo. Strength gains were seen at maintenance doses of 8 g a day or less and were clearest in younger adults, men and people who already train.

Amount studied: 3 to 8 g a day, with or without a loading phase

Supports gains in lean body mass when combined with resistance training*^2,4,11

Moderate evidence

A meta-analysis of 35 randomized trials (1,192 people) found that creatine added about 1.1 kg of lean body mass when combined with resistance training, and nothing measurable without exercise. Men gained about 1.5 kg; the gain in women (about 0.3 kg) was not statistically significant, and part of the early gain is water held in muscle, so the grade is moderate.

Amount studied: 3 to 5 g a day with resistance training, often after a loading phase

Adds to the body's own glutamine during very heavy training, when blood levels can dip; a benefit is unproven*^3,9,12

Early evidence

Prolonged, exhausting exercise is linked to a fall in blood glutamine. But a meta-analysis of 25 trials in athletes concluded that glutamine generally has no effect on immune measures, aerobic performance or body composition, and the NIH says research does not support taking glutamine alone to improve performance. One trial in 16 adults found less soreness and faster strength recovery at about 0.3 g per kg of body weight a day, roughly 21 g for a 70 kg person.

Amount studied: About 0.3 g per kg of body weight a day in the soreness trial, roughly 21 g for a 70 kg adult; up to about 45 g a day in others

Supplies glutamine, a fuel for cells of the gut lining; a benefit from 3 g a day is unproven*^5,13,14,15

Early evidence

The fuel role is established physiology. But a 2024 meta-analysis of 10 trials (352 adults, mostly people under medical care) found no overall effect on gut permeability, with an effect only at more than 30 g a day. In 10 men running in the heat, single doses of about 15 to 54 g lowered a marker of gut permeability, while about 20 g did not help in another trial of 10 men. None of these tested a dose near 3 g.

Amount studied: Single doses of about 15 to 54 g before exercise, and more than 30 g a day in trials of people under medical care

What the trials that gave both found

Lehmkuhl 2003: 29 college track and field athletes took creatine alone, creatine plus 4 g of glutamine a day, or placebo for 8 weeks of training. Both creatine groups gained more body mass and lean mass than placebo and raised their early power output on a cycle test. The abstract does not describe the glutamine group beating the creatine-only group.¹
da Silveira 2014: 32 military police officers took creatine, glutamine or placebo over three months of training, and the abstract reports no difference between groups. The two supplements were given to separate groups, so this is not a test of the pair.¹⁶

Both were small studies in young, active people, and we read only their abstracts. They fit the broader picture in NIH's summary: the research does not back taking glutamine alone for performance, and about 45 g a day for 6 weeks did not raise strength or lean mass.^3,6

Amounts, side by side

What the sources describe and what one of our servings gives^1,2,3,4,6,17
	Creatine	L-glutamine
Typical intake from food	1 to 2 g a day with meat in the diet	3 to 6 g a day from protein foods
Amounts used in studies	3 to 5 g a day, or 20 g a day for 5 to 7 days when loading	About 21 g a day for soreness, almost 45 g a day for 6 weeks of training, 4 g a day in the pairing trial
Tolerable upper intake level	None set	None set
One serving of ours	5 g of creatine monohydrate	3.15 g of L-glutamine

The one place a scoop of ours matches a study is the pairing trial, which used 4 g of glutamine a day against the 3.15 g on our label. The glutamine trials that reported a result for gut or soreness measures used far more, from about 15 g to 54 g.^1,5,17

Timing and mixing

A 2026 review of exercise studies counted 11 human trials that gave glutamine before exercise, 2 that gave it after exercise and 1 that gave it both before and after. Trials that compare before with after directly are extremely limited, so the review does not name a best time.¹⁸

Trials that gave creatine just before or just after weight training found similar gains in strength. In one 32-week trial in adults aged 50 to 71, strength rose about equally with either timing, and the group taking it after training gained more lean tissue than the placebo group.^19,20,21,22

With no tested best time for either, the practical point is the drink. The prescription glutamine label says to mix it into a cold or room-temperature drink and not a hot one, and dissolved creatine breaks down faster in warm or acidic liquids. One cool glass suits both powders.^23,24

What's in ours

What’s in ours

Creatine: Creatine Monohydrate, 5,000 mg per serving, from the label
Creatine + Electrolytes: Creatine Monohydrate, 5,000 mg per serving, from the label

What’s in ours

BCAA 2:1:1: L-Glutamine, 1,000 mg per serving, from the label

Our L-Glutamine gives 3.15 g a scoop. Our BCAA 2:1:1 also carries 1 g of L-glutamine in each serving, so using it alongside the single-ingredient powder brings the day's total to 4.15 g. That is still far below the amounts in most of the glutamine studies.^1,5

Who should ask first

Glutamine is broken down to ammonia, and a safety review says high intakes are inappropriate for people with liver or kidney impairment.¹³

Researchers note that very large single doses taken before exercise, about 0.9 g per kg of fat-free mass, are often poorly tolerated, while about 20 g was well tolerated in their trial.¹⁵

A small rise in blood creatinine on lab tests, without a change in estimated kidney filtration²⁵

The prescription L-glutamine label says there are no data on its use in pregnant women, and no data on glutamine in human milk or on its effect on a breastfed infant.²³

Ask a doctor first about glutamine if you have liver disease, a urea cycle disorder, kidney disease or cancer, or are in cancer treatment, because glutamine is broken down to ammonia.¹³
Ask a doctor first about creatine if you have kidney disease or reduced kidney function, or take medicines that affect the kidneys.²⁵
Ask first about either one if you are pregnant or nursing or are under 18, and tell a doctor about both before a kidney blood test.^8,26

Questions people ask

Does glutamine help creatine work better?

No source we read says so. In the one trial we found that gave creatine with 4 g of glutamine a day, both creatine groups did better than placebo, and the abstract does not describe an added gain from the glutamine. Creatine's own record is strong without it.^1,2

Should you take L-glutamine and creatine at the same time?

No source we read says to separate them or to combine them. Trials of glutamine timing are too few to name a best time, and creatine gave similar strength gains just before or just after training. A cool or room-temperature drink suits both.^18,19,20

Does L-glutamine reduce soreness?

One trial of 16 young adults found lower soreness ratings after hard leg exercise at about 0.3 g per kg a day, roughly 21 g for a 70 kg person. Our scoop has 3.15 g, and no trial we read tested an amount near it.^3,17

Can the two upset your stomach?

They can in large servings. A 10 g creatine serving caused loose stools more often than two 5 g servings in a trial of 59 soccer players, and very large single doses of glutamine are often poorly tolerated. Ask a doctor first if you have kidney or liver problems.^15,27

See what we make

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See the Full Measure line Creatine + Electrolytes Creatine BCAA 2:1:1

Sources

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.