Citrulline

Evidence ratingModerate

A non-essential amino acid that acts as a nitric oxide precursor, promoting vasodilation and improving blood flow and oxygen delivery to muscles. Has comparatively strong evidence as a pre-workout. Most research uses the citrulline malate complex.

An ingredient with growing research

Buy

(PR)

View on Amazon View on iHerb

The links below include affiliate links (PR).

Effects reported in research

Improved muscular endurance (increased repetitions confirmed in research)

Reduced post-exercise muscle soreness (DOMS)

Enhanced pump sensation through vasodilation

Support for high-intensity anaerobic performance

Dosage & timing

6–8 g as citrulline malate, or 3–6 g as L-citrulline.
Take 30–60 minutes before exercise.

Cautions

•No serious side effects currently reported.
•If taking antihypertensive medication, consult a doctor as blood pressure may drop excessively.

Supporting research

Randomized controlled trial

Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness

Journal of Strength and Conditioning Research, 2010

An RCT examining a single 8 g dose of citrulline malate during bench press to exhaustion in trained males. Versus placebo, repetitions increased by an average of 52.92%, post-exercise muscle soreness (DOMS) fell by 40%, and perceived fatigue was significantly lower. It demonstrates a single-dose pre-workout effect, but the design is short-term with a relatively small sample.

View study details

Last checked: 2026-06-23