Bulbine natalensis is a South African medicinal plant traditionally used as an aphrodisiac and to enhance male sexual function. Its popularity has grown in supplements marketed for erectile dysfunction (ED) and testosterone boosting. There is some scientific evidence supporting its use: animal studies have demonstrated that Bulbine natalensis extracts may increase serum testosterone, luteinizing hormone, and improve sexual behavior parameters in male rats. For example, a 2010 study by Yakubu and Afolayan reported improved penile reflexes and increased mounting frequency in rats, along with elevated testosterone levels after administration of Bulbine natalensis extract. These effects are hypothesized to be due to saponins and other phytochemicals present in the plant.

However, there are limitations. The available evidence is almost entirely preclinical, with a lack of robust, peer-reviewed human clinical trials assessing efficacy or safety for ED. Some animal studies have raised concerns about potential toxicity at higher doses, particularly regarding liver and kidney function. Human data are limited to anecdotal reports or traditional use.

In summary, while there is scientific interest and some supportive animal data regarding Bulbine natalensis for erectile dysfunction and androgenic effects, the evidence is preliminary and rated low (2/5) due to the lack of clinical trials. More rigorous human studies are required before its use can be recommended for ED.