Across 3 studies, all reported beneficial effects of spirulina on reducing body mass index (BMI), with effect sizes ranging from small to moderate. The most recent meta-analysis (2025) found a statistically significant moderate reduction (WMD: -0.58 kg/m², P=0.001). Evidence is strongest in adults with metabolic syndrome, though dose ranges were inconsistently reported (20 mg to 6 g daily).
Caveats: Evidence base is small (only 3 studies) — conclusions should be considered preliminary. Available evidence is overwhelmingly positive — clinical literature in this area is subject to publication bias (null-result studies are less likely to be published or indexed). Doses varied widely (20 mg to 6 g daily) with no clear convergence.
BMI; WMD: -0.58 kg/m²; P = 0.001
This seaweed pigment can reduce obesity, body mass index (BMI), hypertension, hyperglycemia, and dyslipidemia.
Spirulina supplementation significantly reduced ... body mass index (BMI) (WMD: -0.40; p = 0.025)