Can You Take L-Arginine and L-Ornithine Together?

Use extra care with this pair

The short answer

L-Ornithine and L-Arginine are both part of the urea cycle and share transporters. While they are sometimes combined for GH release, stacking high doses of both may overload the urea cycle, causing ammonia processing strain.

How to arrange timing

Research suggests using moderate doses when combining L-Ornithine and L-Arginine. Avoid exceeding a combined dose of 10g/day.

Reference

Reference noted for this combination: Sugino T, et al. L-ornithine supplementation attenuates physical fatigue in healthy volunteers. Nutr Res. 2008;28(11):738-743.

Important context

Whether supplements suit you together also depends on dose, product formulation, health conditions, and medication use. Ask a doctor or pharmacist first if you take medication, are pregnant or breastfeeding, or have a chronic condition.