"We normally see this condition in elderly men, so it raises an alarm", Jégou said.
The study involved 31 men (ages 18 to 35) who were randomly assigned to take ibuprofen (two doses of 600 mg each) or a placebo every day for six weeks.
The human brain compensates for testosterone deficiency by producing luteinizing hormone (LH), which sends a signal to the testicles to produce more testosterone.
Within just two weeks, it seems that the testosterone-producing hormones in the subjects became linked to the amount of ibuprofen in their blood.
"This repression results in the elevation of the stimulatory pituitary hormones, resulting in a state of compensated hypogonadism, a disorder associated with adverse reproductive and physical health disorders". The condition arises when the body has to boost levels of testosterone because normal production in the testes has fallen. "Using a unique combination of a randomized, controlled clinical trial and ex vivo and in vitro approaches, we report a univocal depression of important aspects of testicular function, including testosterone production, after use of over-the-counter ibuprofen", the paper reads.
Men who take ibuprofen for long periods of time could be putting their fertility at risk.
To avoid these side-effects, doctors caution against taking Ibuprofen for more longer than ten days in a row, per the FDA's warning.
This resulted in hypogonadism, which is associated with infertility and increased risk of cardiovascular diseases like stroke and heart failure. That number rose to a 23 percent decrease after 44 days.
The drugs are considered "anti-androgenic", which means they lower the amount of hormones present in males.
The study comes as several studies show that infertility rates are on the rise in several areas of the world.
However, for men, it could compromise their ability to procreate, a new study suggests. So not only is the shrinking of your balls concerning on a personal level, it could also suggest you're going to die earlier.
For now you don't need to worry unless you're a daily user of ibuprofen, and even then, more research will be needed before everyone's shouting about the dangers of painkillers. But researchers are concerned about long-term use among athletes.