Research synthesisModerate evidenceModerate effect5 studies · 3 beneficial · 2 neutral · 0 harmful
Across 5 studies, 3 reported beneficial effects of L-arginine on systolic blood pressure, with effect sizes ranging from moderate to large (one moderate, one large, one moderate). The remaining 2 studies found neutral effects. Evidence is strongest for pregnant women and elderly populations, but results are mixed: a meta-analysis in pregnant women (2028 participants) showed a moderate reduction (MD -5.64 mmHg, very low certainty), while another systematic review in high-risk pregnancies found no statistically significant difference. One study in middle-aged/elderly individuals reported a large reduction (-10.44 mmHg) when combined with L-citrulline. Doses and durations were not consistently reported across studies.
- Studied populations: pregnant women, elderly individuals
Caveats: Evidence is mixed: two neutral studies (one in high-risk pregnancies, one in healthy young males) suggest L-arginine may not be effective in all populations or contexts. The beneficial effect in pregnant women comes from a meta-analysis rated as very low certainty, and the largest reduction was observed with combined L-arginine and L-citrulline, not L-arginine alone. Doses and forms were largely unspecified, limiting generalizability. No publication-bias flags were triggered (beneficial proportion 60%, significant proportion 60%).
Generated Jul 13, 2026