When you think of testosterone you might think of fast cars, tackle football, and hot wing eating competitions. Although present in both men and women, testosterone is the dominant sex hormone in men. There are many associations between testosterone and traditionally "manly" things. But this hormone is in charge of much more. For example, new research presented at the European and International Congress on Obesity found that men with low testosterone were able to reverse weight gain with testosterone shots.

Even before someone is born, testosterone is at work driving genital formation. It is testosterone that causes facial hair and muscle growth in the teenage years. This is also around when testosterone production peaks, and levels of the hormone slowly decline after that. According to the National Institute of Health testosterone is important for sex drive, muscle strength, facial hair and sperm production, as well fat distribution and bone mass.

Low Testosterone Can Cause Weight Gain – and More

Studying men with clinically low testosterone, researchers from Germany and the United Arab Emirates looked almost 800 men with low testosterone levels in their blood, finding that over half were obese. Of this group, a little over half opted to get testosterone injections. The men who received the testosterone treatment lost inches off their waistlines. Over the course of the 11-year study, these men lost about 50 pounds. The men not receiving testosterone gained, on average, a little over 13 lbs.

There was more than a cosmetic change too. None of the men receiving testosterone treatment had heart attacks during the study, while a quarter of the men not getting the hormone did. Although patients in both group died over the 11-year period, the number of deaths in the testosterone group was a third of the number of untreated men. Most deaths were due to traffic, sport accidents and post-surgical infections, according to a press release about the research.

The men in both groups were obese at the start of the study and about half in each group had type 2 diabetes. By the end of the study, almost all the untreated patients had type 2 diabetes, while there had been no new cases in the testosterone group.

Not a Miracle Cure

Testosterone is not a miracle cure for aging and should not be taken without your doctor’s advice. In 2014 the Food and Drug Administration issued a warning that testosterone therapies might increase the risk of stroke, heart attack and death. Other reported side effects of using testosterone include:

  • An increase the number of total red blood cells, which can cause blood clots
  • Sleep apnea, new or worsening
  • Acne and other skin issues
  • Enlarged breast tissue
  • Shrinking of testicles and reduced sperm production

When properly administered by a doctor, testosterone might have benefits in reversing weight gain and avoiding serious health conditions that can be caused by obesity, but without a doctor’s supervision, the side effects can be serious. Until more research has been done, especially for those without clinically low testosterone, talking to a doctor and making good lifestyle choices might be the safest road to weight loss.