A commonly used painkiller could lead to a loss of sex drive if used for long periods by men, a study warns.
Researchers found that ibuprofen affects the production of sex hormones.
People using the drug for long term pain relief could suffer muscle loss, lower libido and depression.
While use of the painkiller for an occasional headache is unlikely to cause a problem, many people take the drug for long term management of pain.
Sufferers of chronic arthritis and athletes with long-term injuries are two groups of people who rely on the drug for reducing pain.
People using ibuprofen for long term pain relief could suffer muscle loss, lower libido and depression, according to a new study
The study tested the effects of 600mg of Ibuprofen on volunteers – three tablets – as well as studying the effect on cells taken from testicles in the laboratory.
The authors warn that long term use of ibuprofen could lead to a condition called compensated hypogonadism.
The painkiller does not affect testosterone directly – but sex hormones that regulate testosterone’s production.
The authors warn ‘ibuprofen appears to be the preferred pharmaceutical analgesic for longterm chronic pain and arthritis.’
‘Therefore it is also of concern that men with compensated hypogonadism may eventually progress to overt primary hypogonadism, which is characterized
by low circulating testosterone and prevalent symptoms including reduced libido, reduced muscle mass and strength, and depressed mood and fatigue.’
Dr Allan Pacey of the University of Sheffield said that the effects of over the counter painkillers such as Ibuprofen has been of increasing interest in recent years.
Most of the research has been the effect on the developing male foetus if the pregnant mother takes the drug.
He said: ‘To my knowledge there has been very little research on how the use of painkillers might affect the testicle of a fully grown adult.’
‘The results suggest that long-term use (several weeks) of ibuprofen can affect the production of the male hormone by the testicles.
‘The authors speculate that this could have health implications for such men, given the known links between the disruption of such hormones and cardiovascular disease, diabetes and infertility.
‘However, this is currently speculative. So, for the time being, I would urge men who need to take ibuprofen to continue to do so. However, it is recommended that if men (or women) need to take it for more than three days consecutively then they should first consult their family doctor.’
Dr Ali Abbara, Senior Clinical Lecturer in Endocrinology at Imperial College London said the effects of the ibuprofen were ‘mild’ even after six weeks.
But he said: ‘If men are known to have impaired testicular function and take ibuprofen regularly, then it would not be unreasonable to consider other painkillers until more data is available to better inform this potential risk, although we must bear in mind that many alternative painkillers may also affect the reproductive axis.’
Dr Richard Quinton, Senior Lecturer in Endocrinology at Newcastle University, and member of the Society for Endocrinology, said: ‘In women pregnant with male foetuses, there are already data suggesting a potential long term effect on testicular function of the offspring of regular paracetamol taken during pregnancy.
He added: ‘Hitherto, most warnings regarding this family of painkillers have focused on limiting long term use in the elderly to prevent gastrointestinal, renal and cardiac adverse effects. This study should give pause for thought to sportsmen using them routinely for exercise-induced aches and pains.’