The warning label for Propecia, a popular anti-baldness drug, already lists loss of libido as one possible side effect. However, more and more men are complaining of persistent disinterest in sex.
April 11, 2012: The U.S. Food and Drug Administration (FDA) announced today that it will be updating the label information for Propecia, after the FDA received hundreds of adverse event reports from men who were injured by this drug. The new labels will include more warnings about the risk of persistent sexual side effects. Propecia labels will now warn about the possible risk of libido disorders, ejaculation disorders, and orgasm disorders, problems which often do not resolve when Propecia is discontinued. While taking Propecia, the FDA warns that men may also suffer fertility problems and poor semen quality.
Propecia is a medication that is used by millions of men to reduce hair loss caused by genetic male pattern baldness. Propecia contains 1 milligram of finasteride, a drug that was initially developed to reduce enlarged male prostate. Finasteride works by inhibiting 5-alpha reductase, which is an enzyme that converts testosterone into dihydrotestosterone (DHT). Inhibiting 5-alpha reductase reduces DHT by 75-80%. This hormonal imbalance can lead to an increased amount of estrogen, which can cause severe sexual side effects. In addition to loss of libido, sexual side effects of Propecia can include erectile dysfunction, decreased semen volume, gynecomastia (growth of male breast tissue), and more.
What is Loss of Libido?
Though there is no clear definition of loss of libido, it typically means a lack of interest in sex that lasts for months or years. It is not necessarily a lack of sex in general — many things other than loss of libido can get in the way of having sex, but the desire is still there. Men with loss of libido have minimal or no desire for sex.
Men who are suffering from loss of libido typically exhibit similar symptoms. They have no interest in touching their partner outside the bedroom, they do not have feelings of connection after sex, they do not look forward to sex, they do not have sexual fantasies about their partner, and sex occurs less than once per month. When sex does occur, it is mechanical and routine, and one partner is the initiator and the other is pressured into having sex.
Loss of libido can cause severe psychological distress for a man. Men often link their sexuality to their masculinity. One study found that only 23% of men who suffered loss of libido said they still feel happy about life in general. If the psychological problems lead to depression, this can also reduce interest in sex.
Other Propecia side effects can exacerbate loss of libido. Many men taking Propecia suffer from erectile dysfunction, physical changes such as gynecomastia, or other problems that can cause performance anxiety and self-consciousness.
Studies of Propecia and Loss of Libido
A study by Dr. Michael Irwig examined data from men who were participating in an online forum. The men were all suffering from persistent side effects of Propecia. Of the men who were participating in the study, 92% had decreased arousal. Furthermore, men reported that they had a decreased number of sexual episodes per month.
The study was published in the Journal of Sexual Medicine in June 2011.