Sildenafil (Viagra) is promoted as a drug for the treatment of erectile dysfunction, but that is not the only benefit users gain. According to a research study published in the FASEB Journal, the ED drug helps change white fat to brown fat, increasing the likelihood of weight loss.

Cyclic GMP plays an important part in the process of fat storage. The function of cyclic GMP in controlling blood flow and blood pressure is well established, but recent research suggests it also plays a part in the type of fat the body chooses to store. Sildenafil stops the breakdown of cyclic GMP, which increases the likelihood the body will store more brown fat. Brown fat pulls energy (calories) from white fat. Storing more brown fat increases the number of calories needed per day; therefore, increasing brown fat stores can increase calorie burn, resulting in weight loss.

The study, completed by the Federation of American Societies for Experimental Biology, was performed on mice. This is not the first brown fat study, but it is the first to reveal a connection between the ED drug sildenafil and brown fat storage. Researchers hope to complete a study on the impact of the drug on human weight, weight loss and body fat composition in the near future.

Taking sildenafil for ED is not without risk. Side effects associated with the drug include irregular heartbeat, swelling of extremities, changes in vision, headache, trouble remembering, back pain and upset stomach. Sildenafil can cause an erection. If an erection lasts more than four consecutive hours, patients should seek medical attention as damage to penile tissue can occur.

The editor of the FASEB Journal chimed in on the study, “Clearly, size matters when it comes to our weight. Numerous studies show that obesity is a risk factor for virtually every human disease and that obesity is epidemic. The finding that [sildenafil] and similar drugs can change our body fat composition has major implications.”

Source: Michaela M. Mitschke, Linda S. Hoffmann, Thorsten Gnad, Daniela Scholz, Katja Kruithoff, Peter Mayer, Bodo Haas, Antonia Sassmann, Alexander Pfeifer, and Ana Kilić. Increased cGMP promotes healthy expansion and browning of white adipose tissue. FASEB Journal. April 2013 27:1621-1630; doi:10.1096/fj.12-221580.