Citrulline: Research · Nutrient Desk

Can it help with another repetition?

A 2021 synthesis of eight studies found a small increase in repetitions during strength training after citrulline malate. A broader 2026 analysis also found small, context-dependent performance benefits, with low to very low certainty. Reliable target populations and dosing remain unclear. 1 2

Strength TrainingMixed

A possible small performance benefit is different from established long-term gains in strength. 1 2

What about endurance?

A 2023 analysis of nine studies in young, healthy adults found no significant improvement in time to exhaustion or completion time after acute citrulline. The 2026 malate review found exploratory endurance signals that were not robust in sensitivity analyses. 2 3

Endurance and staminaMixed

The findings do not support a dependable endurance improvement across settings. 2 3

Does it lower blood pressure?

A 2025 review of middle-aged and older adults found lower blood pressure across trials of citrulline, watermelon, and combinations with arginine. Because interventions differed, the pooled result cannot be assigned to pure citrulline alone. 4

Blood pressureMixed

This is a promising circulation finding, with uncertainty about which preparation produces the benefit. 4

What is the evidence for erections?

In 24 men with mild erectile dysfunction, erection hardness improved more often during a month of 1.5 g daily L-citrulline than during the preceding placebo month. Everyone received placebo first, so the small, single-blind study needs confirmation with stronger controls. 5

Male Sexual PerformanceToo little evidence

The study concerned erection hardness, not sexual desire. 5

Effects by health goal

Open an effect to see the studies behind its rating. Bars show the size of the effect; the letter grades the evidence.