Research synthesisLow evidenceModerate effect3 studies · 2 beneficial · 1 neutral · 0 harmful
Across 3 studies, 2 reported beneficial moderate-sized effects of L-Arginine on reducing pain in clinical populations (sickle cell disease vaso-occlusive episodes and radiation-induced oral mucositis), while 1 meta-analysis found no significant benefit. The two beneficial RCTs used short-term dosing (100 mg/kg/dose three times/day in children or 5 g/day in adults) and showed effects within days to 7 weeks. The evidence base is small and includes a neutral meta-analysis, limiting the generalizability of the positive findings.
- Studied populations: patients with sickle cell disease experiencing vaso-occlusive pain episodes (children and adults) and head/neck cancer patients with radiation-induced oral mucositis
Caveats: Evidence base is small (only 3 studies) — conclusions should be considered preliminary. The largest study (meta-analysis of 830 sickle cell patients) found no significant effect on pain scores, while two smaller RCTs (n=20 and n=23) reported statistically significant benefits, suggesting possible population-specific effects or publication bias. Doses varied across studies and no form data were extracted, so optimal dose and formulation remain unclear.
Generated May 13, 2026