More than a million men have smeared testosterone gels on their bodies in recent years, hoping it would rejuvenate them, energize them, and increase their libido. But until now, there has never been a rigorous study asking if there were any real benefits to testosterone therapy for healthy men with so-called low T.
The first results of such research were published Wednesday in The New England Journal of Medicine. Although it found at best modest benefits, mostly in sexual functioning, it is a landmark study, said Dr. Eric S. Orwoll, a professor of medicine at Oregon Health and Science University, because it provides the first credible data on testosterone’s effects on some of the problems it is thought to resolve.
Some doctors said they hoped the modest results might bring some sanity to the testosterone frenzy of recent years. “Frankly,” said Dr. Sundeep Khosla, a dean at the Mayo Clinic College of Medicine, “there is a lot of abuse.” Men lured by advertisements seek the drug, and Dr. Khosla said he had heard of doctors who prescribed it without first measuring the man’s testosterone levels to see if they were low.
“What I hope is that this will bring a more conservative approach,” Dr. Orwoll said. “There is a lot of prescribing out there, and it doesn’t look like, for the average man, it will have a big effect.”
The study, led by the Perelman School of Medicine at the University of Pennsylvania and funded by the National Institutes of Health and AbbVie, the maker of the testosterone gel AndroGel, involved 790 men 65 and older with low testosterone levels for their age.
Testosterone levels normally fall as men age, but these men had levels on the low end — below 275 nanograms per deciliter of blood. Some of the men said they had lost their sexual drive, others said they were walking much slower than they used to, and others said they just felt blah, as if they had lost their zest for life. The men were randomly assigned to use AndroGel or a placebo for a year.
As expected, the men who used AndroGel ended up with markedly higher testosterone levels — those of men 19 to 40. But the question the researchers wanted to know was: Did they feel or act any differently?
Men who had said their sexual functioning had been flagging reported moderate increases in their interest in sex and in their performance, although when it came to erections, a drug like Viagra or Cialis would be more effective, the researchers reported. Those who said they felt blue reported a small improvement in mood. But the drug had no discernible effect on vitality or walking speed in men with those complaints.
The study was too small and short-term to address another longstanding question about testosterone gels: whether using them increases the risk of heart disease and prostate cancer and other conditions. And that, said Dr. Richard J. Hodes, the director of the National Institute on Aging, was deliberate.
