Evidence: Weak Taken before training: what counts is the amount in the serving you take.
In our pre-workout label study, 45 of 52 best-selling pre-workouts list l-citrulline and 27 reach the research dose.
Studies used 6–8 g of citrulline malate (2:1) 40–60 minutes before training. Shown here as the L-citrulline in that: two thirds, 4–5.33 g. The pooled effect is small and a strength meta-analysis found none, so the evidence is weak.
Sources
Gough LA, Sparks SA, McNaughton LR, et al. A critical review of citrulline malate supplementation and exercise performance. Eur J Appl Physiol. 2021;121(12):3283-3295.
Supports the research dose. Where: Abstract: "a single acute 8 g dose of CM ... has been the most common approach". Read the source, checked 7 Oct 2026.
Vårvik FT, Bjørnsen T, Gonzalez AM. Acute Effect of Citrulline Malate on Repetition Performance During Strength Training: A Systematic Review and Meta-Analysis. Int J Sport Nutr Exerc Metab. 2021;31(4):350-358.
Supports the research dose. Where: Abstract: "Supplementing with 6-8 g of CitMal 40-60 min before exercise increased repetitions". Read the source, checked 7 Oct 2026.
Citrulline supplements we've checked
16 citrulline supplements, each judged on how much a day its label's own directions give. See them all, ranked.