Some men have testosterone so low that it's a medical problem.

But how low is too low? And how many men really need a pharmaceutical version of the hormone to replace the testosterone that they might be missing?

Answering those questions isn't so easy. Testosterone levels can vary. And symptoms attributed to low testosterone, such as fatigue and a drop in libido, can be caused by plenty of other things, like depression and, gasp, normal aging!

Doctors who specialize in hormone-related illnesses came up with a guidelines a few years back that urges a careful approach, saying a diagnosis of problems that require treatment should only be made in "men with consistent symptoms and signs and unequivocally low serum testosterone levels."

But the hasn't stopped drugmakers from touting the benefits of testosterone therapy and mounting awareness campaigns that aim to get men talking with their doctors about treatment.

Now there's a study in JAMA Internal Medicine that suggests the marketing campaigns have had an effect. Prescriptions for testosterone to men 40 and older rose threefold over the decade ending in 2011 — from 0.81 percent to 2.91 percent of men in the study group. The data analyzed covered nearly 11 million men across the country.

And it turns out, contrary to the specialists' recommendations, a quarter of men who got testosterone prescriptions hadn't even had a proper testosterone test beforehand. Lead author of the study, Jacques Baillargeon, called that concerning in a video describing the work.

There are side effects from testosterone treatment, including increased risk for heart disease and some cancers. The evidence for benefits isn't clearcut.

Two companion commentaries in the journal describe the marketing of low testosterone, or so-called Low T.

One piece comes from a medical writer who has been directly involved, sometimes as a ghostwriter. The sales of testosterone are being driven by "a sophisticated marketing effort to define low testosterone as a disease for which the treatment is [testosterone-replacement therapy]," writes. "I know this because, as a professional medical writer, I have helped craft that message for transmission in a range of media to both physicians and consumers."

Drs. Lisa Schwartz and Steven Woloshin, who work at the Veterans Affairs Outcomes Group and Dartmouth's med school, say the "Low T campaign provides a template for how disease awareness campaigns" are used to boost drug sales. They lower the bar for diagnosis, raise the stakes for intervention and spin the evidence to support that course of action:

"There are a lot of American men. Some are grumpy. Some are tired. Some may not even be interested in sex at the moment. And all of them are aging. This is the intended audience ... ."

And here's something you don't see every day, Schwartz and Woloshin managed to sneak a bit about Low T on The Colbert Report into an academic journal to make a point about the marketing message:

"A man on TV is selling me a miracle cure that will keep me young forever. It's called Androgel ... for treating something called Low T, a pharmaceutical company–recognized condition affecting millions of men with low testosterone, previously known as getting older."

AbbVie, formerly part of Abbott Labs, is the maker of Androgel and the marketer behind the website.

Company spokesman Greg Miley defended AbbVie's approach in a statement emailed to Shots:

"Disease state awareness initiatives serve an important role by enhancing awareness of health conditions, educating patients about treatment alternatives, and referring consumers to qualified health care practitioners. This is why the [Food and Drug Administration] encourages drug and device manufacturers to develop them.

AbbVie's low testosterone efforts follow FDA's guidance and were developed to educate men who may be at risk for, or have, low testosterone, so they can have the appropriate dialogue with their physician to determine if testing and treatment may be appropriate."

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