L-glutamine
Glutamine peptide, Alanyl-glutamine, Endari, Sustamine, NutreStore
Forms: Free L-glutamine powder or capsules and dipeptides (alanyl-glutamine, 'glutamine peptide'); in the US a pharmaceutical glutamine powder (Endari) is approved for sickle cell disease.
An amino acid important for immune cells and the gut lining. The body makes its own, but blood levels fall during prolonged exercise and heavy training. Sold for recovery, gut and immune support.
Legal status: Sold freely as a supplement and not prohibited by WADA; in the US a prescription glutamine powder is also approved for sickle cell disease. Varies by country.
What it gives
What people use it for and what the sources report. Strength is a general category from the literature: mild, clear or strong.
Purpose
Used for faster recovery and less soreness, fewer infections in heavy training, gut-barrier support and as an 'anti-catabolic' for muscle. Well-controlled studies in healthy, well-fed athletes give these claims little support.
What people seek and what studies show
A meta-analysis of 25 trials in athletes found generally no effect on immune markers, aerobic performance or body composition, apart from a small drop in body weight. Keeping blood glutamine up after exercise did not prevent post-exercise immune changes. Some trials show better gut-permeability and muscle-damage markers, others none.
Effects
Evidence: Limited human data — some human studies, small or short
Sought effects by goal (as reported)
Possible side effects
Possible does not mean certain: whether they appear depends on dose, duration, individual response and monitoring. Below — what to watch for and how to notice it early.
2 possible side effects
level · how often it is reportedWhat the levels mean
Level: general category from the literature, not your personal risk
How often
- common
- reported often
- possible
- reported in some people
- rare
- reported occasionally
How to lower the risks
For 1 of 2 possible side effects there are specific ways to lower the chance: everyday measures, supplements and options a doctor may consider. For the rest — general advice. No measure removes a risk completely.
Low-level side effects
How each option helps (2)
- Working with a doctor — Assesses persistent vomiting or severe belly pain (possible pancreatitis or gallstones) and adjusts prescribed GLP-1 treatment when nausea persists.
- Pancreatin + dimeticone (Pankreoflat) — May ease heaviness and gas after meals; can cause nausea or diarrhea. Not for pork or cow's milk protein allergy (anaphylaxis reported) or early acute pancreatitis.
Check-ups and blood tests
Which tests and check-ups to do and when. This is a guide — agree the exact schedule with your doctor.
For women
The prescription form's label reports no data in pregnancy or breastfeeding, so benefits and risks there should be weighed with a doctor.
Myth & fact
“Does glutamine build muscle or stop muscle breakdown?”
Not in healthy, well-fed people. In a 6-week weight-training trial it added no strength or lean mass and did not lower a urinary marker of muscle breakdown compared with placebo.
Combinations
No specific combination notes for this substance yet. The stack check still adds up side effects that several substances share.
Sources
Possible side effects by body system, combinations, how to lower the risks and which tests to do — free.
Open the stack check