Oxytocin may offer hope for male sexual dysfunction

By Dr. Ananya Mandal, MDApr 10 2012

The hormone oxytocin that is also called the “love hormone” since it plays a role in the bond between a mother and baby may also improve sexual function - at least in men with Asperger’s syndrome - according to a published case report.

Doctors at the San Diego Medical Center discovered this side effect of the so-called love hormone while treating a 32-year-old father of three who had been diagnosed with ADHD and fit the criteria for Asperger’s, a high-functioning form of autism. Medication for the ADHD and treatment with antidepressants for his social anxiety had failed, the latter resulting mainly in sexual dysfunction that was not relieved by medications. Since some research suggests that oxytocin can improve social functioning, the patient agreed to an “off label” trial of the drug, which can be administered as a nasal spray.

Oxytocin, a naturally occurring hormone, is thought to be critical in helping form the bonds that unite monogamous mammals - both humans and animals - and parents and their offspring. In humans, it has been shown to increase trust and the ability to read social signals, and it is currently being tested for the treatment of depression, schizophrenia and Asperger’s.

Neither the doctor nor the patient was expecting a change in sexual function. In the current case study, published in the Journal of Sexual Medicine, the drug produced small but noticeable improvements in the patient’s social behaviour that were remarked upon both by colleagues at work and by the man’s wife. She reported that “he wants to be closer,” which led to more intimacy. The man experienced a 46% improvement in sexual function, as measured on a standard scale, including more desire, more arousal, improved erectile function and even better orgasms. The spray also produced emotional benefits. The man said he found it easier to be affectionate towards his wife, while she said he wanted to be closer to her and was more tactile.

When he occasionally forgot to renew the prescription, these effects disappeared.

Researchers suggest more studies to prove the theory. Many drugs look effective before being subjected to placebo-controlled trials, and subjective experiences like sexual function are particularly prone to placebo effects.

Further, it’s possible that oxytocin’s benefit would apply only men with Asperger’s whose sexual relationships may be affected by their social problems. Lead author Dr. Kai MacDonald, assistant clinical professor of psychiatry at the University of California, San Diego, notes that oxytocin doesn’t improve social skills much in those who are already socially proficient, and the same may be true with regard to sex. “Research indicates that oxytocin elevates a low floor to average, but does not take you higher,” he says.

Mike Wyllie, one of the team of scientists that discovered and developed Sildenafil citrate for pharmaceutical giant Pfizer, said that for some men who have had surgery, the little blue pills can work in as few as 10 per cent of cases. Dr Wyllie said that a drug based on oxytocin could have “blockbuster potential”. However, he warned that drug watchdogs may be cautious about approving a medicine that has emotional as well as physical effects.

Consequently, the authors call for more research. Since MacDonald’s group is presently funded to study only conditions like schizophrenia, depression and addictions, the researchers are observing the sexual effects of oxytocin only as side effects for now.