Research synthesisLow evidenceSmall effect3 studies · 1 beneficial · 2 neutral · 0 harmful
Across 3 studies, 1 reported a beneficial moderate-sized effect of L-arginine (in combination with L-citrulline) on reducing diastolic blood pressure in middle-aged and elderly individuals, while 2 studies (including a systematic review in high-risk pregnancies and an RCT in healthy adults) found neutral small or nonsignificant effects. The overall evidence base is small and preliminary, and the beneficial finding came from a meta-analysis of combined supplementation rather than L-arginine alone.
- Studied populations: middle-aged and elderly individuals (beneficial effect seen), pregnant women (neutral), healthy physically active adults (neutral)
Caveats: Evidence base is small (only 3 studies) — conclusions should be considered preliminary. Many of the included studies did not reach statistical significance — effect may be smaller than the predominant direction suggests. The one beneficial finding was from a subgroup analysis of combined L-citrulline and L-arginine supplementation, not L-arginine alone, limiting direct applicability. Doses and study durations were inconsistently reported across studies.
Generated Jun 11, 2026