In the April 2003 edition of PlantLife I questioned the conventional wisdom that chewing the fresh leaves and buds of Catha edulis (Vahl) Forsk. ex Endl. (Celastraceae) decreases libido by pointing out that Xhosa users at Bolo, Stutterheim regard igqwaka or ikambi as a sexual analeptic. (Hirst 2003) The claim that qat decreases libido is above all contradicted by the genealogies of Xhosa chewers.

According to the BBC, it is now official that laboratory researchers at King's College, London have found a chemical in the Catha edulis shrub that could boost the power of men's sperm. The study was recently presented at the conference of the European Society of Human Reproduction and Embryology in Berlin. Researchers say their findings could lead to new products to help couples conceive. (King's College Press Release 2004)

Researchers from the Centre for Reproduction, Endocrinology and Diabetes at King's College examined the effect of cathine, an oxidation or degradation product of one of the principal stimulants in Catha edulis, cathinone, on mouse sperm. They found that cathine accelerated the development of sperm, so it reached the stage when it was fertile more quickly. It then remained in the fertile stage for longer than normal. Early tests on human sperm suggest it is affected by cathine in the same way. The Professor of Reproductive Biology at King's College, Lynn Fraser, told BBC News Online: "It might be relatively easy to develop products." Professor Fraser said if the research on cathine improving sperm production was proven: "We could give it to men to improve sperm production, and to women because it is in the female reproductive tract that the sperm go through this process to become fertile. And the amount that's required isn't that high, so it's not a question of taking very high doses and therefore becoming over stimulated." She said Catha-based products could be used to help couples having trouble conceiving naturally, and in clinics as additives to sperm used in IVF or artificial insemination.