An anonymous reader quotes a report from The Guardian: Men who take high doses of ibuprofen for months at a time may be at greater risk of fertility issues and also other health problems, such as muscle wastage, erectile dysfunction and fatigue, scientists have found. Research on healthy young men who took the common painkiller for up to six weeks showed that the drug disrupted the production of male sex hormones and led to a condition normally seen in older men and smokers. The 18 to 35-year-olds who took part in the study developed a disorder called "compensated hypogonadism" within two weeks of having 600mg of ibuprofen twice a day. The condition arises when the body has to boost levels of testosterone because normal production in the testes has fallen. Doctors in Copenhagen who led the study said that while the disorder was mild and temporary in the volunteers, they feared it could become permanent in long-term ibuprofen users. This would lead to continuously low levels of testosterone, because the body could no longer compensate for the fall. Details of the study are published in the Proceedings of the National Academy of Sciences.