Bulbine natalensis Baker stem found to increase Testosterone by up to 350% in animal studies in 2 weeks. The dose with the optimum response was 25 and 50 mg/kg, with the most best effect at 50 mg/kg. LH and FSH production was increase but exact mechanism not discussed. Only abstract available here.
2 week animal study of Bulbine natalensis Baker stem found to decreased some wbc types. In this short study, it also decreased HDL and increased cholesterol and triglycerides.
Bulbine natalensis Baker stem extract found to increase LH and Testosterone in wistar rats in 7 days at doses of 25 to 50 mg/kg; this effect was not found at 100 mg/kg. The result was an increase in testes size, rate of mating, libido, and fertility.