58
SCORE
L-Ornithine
Sleep · Ammonia detox · Exercise recovery
Tier 3 — Trending
What it is
An amino acid involved in the urea cycle that helps your body clear ammonia, a metabolic waste product. Small trials show it improves sleep quality when taken before bed and reduces fatigue during prolonged exercise. Often combined with L-arginine for growth hormone release, though the GH effect is modest and short-lived. Very safe with no serious side effects reported in clinical studies.
Efficacy
2/5
Safety
4/5
Research
2/5
Onset
3/5
Cost
3/5
Drug-int.
5/5
Dose
400–800 mg before bed for sleep or 2–6 g before exercise for recovery
Time of day & tips
For sleep, take 400–800 mg on an empty stomach 30 min before bed. For exercise, take 1–2 hours before training. Best with water, not a high-protein meal.
Compare or learn more
Compare with another supplement →
Browse by symptom →
Open the full interactive view →