This paper reports on a series of studies investigating the impact of the common analgesic ibuprofen on testicular function. Ibuprofen is a 'pain-killer' that has been available in Australia over-the-counter for many years.

While it has long been recognised that this class of medication can cause gastrointestinal upset and aggravate asthma, its link with impaired male hormonal function is not well established.

These investigators showed that when healthy young men took a moderate dose of ibuprofen, equivalent to three tablets of Nurofen per day, for six weeks, it impaired the function of two testicular cell types responsible for the production of testosterone and supporting sperm development.

Furthermore, the investigators reported that ibuprofen added to testicular cells in culture was capable of blocking the action of key enzymes involved in the production of testosterone.

Taken together, these results support the possibility that anti-inflammatory drugs like ibuprofen could result in lower testosterone levels if taken over several weeks.

Sperm quality was not assessed in the study, but as testosterone and Sertoli cell function play a key role in sperm production there is some theoretical concern that long term use of this drug could potentially negatively impact on male fertility potential.

However, it is presently uncertain if taking a couple of ibuprofen tablets with a headache would cause any significant impairment of testicular function. I believe it is highly unlikely to be the case.

He advised that men should be cautious and not take anti-inflammatory medication for long periods of time without consulting their doctor, especially if they were experiencing symptoms of low testosterone (fatigue, poor libido and mood) or infertility.