About Sutherlandia
South African traditional medicine plant used for immune support. Only 2 human RCTs exist, both safety-focused with no demonstrated efficacy. The HIV trial (Johnson 2015, n=107) showed no change in CD4 count or viral load, and a concerning signal of increased infection burden in the treatment group. The primary bioactive compound (L-canavanine) was undetectable in human plasma at 800mg/day (Tai 2007), raising serious bioavailability concerns. A 2025 critical review in Planta Medica characterized the research base as 'promotional.' Significant drug interaction potential with CYP3A4 substrates and antiretrovirals.
What Sutherlandia supports
- Traditionally used as an immune modulator in South African medicine
- No human RCTs have demonstrated immune efficacy; the only immune-relevant trial showed no benefit
How much Sutherlandia to take
The RDA prevents deficiency. The effective range is what clinical trials used to actually move the outcome.
Effective
400–1200
mg
Based on doses used in the only two human safety trials (Tai 2007: 800mg/day leaf powder; Johnson 2015: 800-2400mg/day). No efficacy dose established — these are safety-trial doses only. Extract equivalence is unstandardized.
Clinical evidence
Limited clinical evidence. Only 2 human trials exist, both safety-focused with no demonstrated efficacy; bioavailability concerns
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