Consumption of liquorice may result in decreased libido in men, according to Dr Decio Armanini (University of Padua, Italy) and colleagues. They evaluated the effect of liquorice on gonadal function in seven healthy men aged 22 to 24. The men were given 7g of liquorice daily, a common level of consumption, the researchers say, which contained 0.5g of glycyrrhizic acid, the active component.
During the period of liquorice consumption, the men's serum testosterone levels decreased. The authors say that liquorice inhibits two enzymes involved in testosterone production.
They conclude that men with decreased libido, sexual dysfunction or hypertension should be questioned about liquorice consumption (New England Journal of Medicine 1999;341:1158).