Consumption of Sutherlandia frutescens by HIV-Seropositive South African Adults: An Adaptive Double-Blind Randomized Placebo Controlled Trial

This was a two-stage, adaptive, double-blind, randomized, placebo-controlled trial in HIV-seropositive adults from KwaZulu-Natal, South Africa. In the 1,200 mg Sutherlandia frutescens arm, 54 participants were randomized and 49 completed; participants were adults 21 to 64 years old, largely female, with CD4 counts above 350 cells/μL and not receiving antiretroviral therapy.

Sutherlandia frutescens dried leaf powder was given as oral capsules at 1,200 mg twice daily for 24 weeks, for a total daily dose of 2,400 mg. The capsules were matched with placebo capsules in a double-blind randomized design.

Sutherlandia frutescens did not improve HIV disease markers and did not show a clear safety advantage over placebo. CD4 count and viral load declined over time in both groups, with no significant between-group interaction effects for CD4 (P = 0.632) or viral load (P = 0.829). The burden of infection was higher in the Sutherlandia arm, with mean BOI 9.0 versus 5.0 days for placebo (P = 0.045), and two serious adverse events occurred in the Sutherlandia arm. The main conclusion was that up to 2,400 mg daily did not meaningfully alter CD4 count or viral load, but a possible interaction with isoniazid preventive therapy may have increased infection burden and warrants further study.

The active-arm sample was modest and the treatment period was only 24 weeks, limiting power to detect smaller effects and longer-term safety signals. The population was restricted to relatively healthy HIV-seropositive adults with preserved CD4 counts and little or no antiretroviral exposure, which limits generalizability. The higher infection burden in the Sutherlandia arm raises concern for a possible interaction with isoniazid preventive therapy, but this signal needs confirmation.