SupplementsAmino acidsPerformanceBlood flow
Citrulline is a “pump” and endurance supplement that, unlike arginine, survives digestion well and raises blood arginine effectively.
Key takeaways
- Citrulline is converted to arginine → nitric oxide, widening blood vessels and improving blood flow.
- It raises blood arginine more effectively than arginine itself, which is largely destroyed in the gut and liver.
- ~6–8 g citrulline malate before exercise may add a few reps and reduce soreness — evidence is mixed and modest.1
- Well tolerated, with little GI upset.
What it is
L-citrulline is a non-protein amino acid (found in watermelon) that the kidneys convert to arginine, the substrate for nitric oxide. “Citrulline malate” adds malate, an energy-cycle intermediate.
The evidence
A critical review found that acute doses (commonly 8 g citrulline malate) produce equivocal but sometimes positive effects on resistance-exercise reps and high-intensity performance; benefits are real but small and inconsistent between studies.1
Dose & how to use
6–8 g citrulline malate (or ~3–4 g pure L-citrulline) about 60 minutes before training.
Safety & who benefits
Safe and gentle on the stomach (unlike high-dose arginine). Most relevant for resistance training and repeated high-intensity efforts.
References
Adult research summary for education, not a prescription. These are food supplements, not treatments for disease.
- Gough LA, et al. A critical review of citrulline malate supplementation and exercise performance. Eur J Appl Physiol 2021. pmc.ncbi.nlm.nih.gov
This article summarises nutrition and exercise science for education. It is not a substitute for individual medical advice; consult a professional before starting a supplement, in pregnancy, or alongside medication.