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• Posted February 22, 2024

Could Hair Loss Drug Finasteride Help Men's Hearts?

The common hair-loss drug in Propecia and Proscar might lower men's risk of heart disease by lowering cholesterol levels, a new study suggests.

Finasteride is used to treat male pattern baldness, and it's also been shown effective in treating an enlarged prostate, researchers said in background notes.

But men who use finasteride also have substantially lower cholesterol levels, according to data gathered by a federal health survey between 2009 and 2016.

"When we looked at the men taking finasteride in the survey, their cholesterol levels averaged 30 points lower than men not taking the drug,"said lead researcher Jaume Amengual, an assistant professor at the University of Illinois Urbana-Champaign.

"I thought we'd see the opposite pattern, so it was very interesting,"Amengual added in a university news release.

Researchers then replicated this finding in lab mice. Mice getting high doses of finasteride had lower cholesterol, less hardening of the arteries, reduced liver inflammation and other related health benefits.

Finasteride works by blocking a protein found in hair follicles and the prostate gland that activates testosterone, researchers said in background notes.

Because heart disease is far more common in men than women, scientists have long suspected that testosterone plays an important role in clogged arteries, researchers said.

"It was just my own curiosity, based on the fact that hormone levels are known to have an effect on atherosclerosis, hair loss and prostate issues,"Amengual said. "So, we decided to dig into it."

Researchers first analyzed data from the National Health and Nutrition Examination Survey.

Although the results suggested an association between finasteride and lower cholesterol, only 155 men out of nearly 4,800 survey respondents reported using finasteride.

"This was not a clinical study in which you can control everything perfectly,"Amengual said. "It was more of an observation that led us to say, 'Okay, now we've seen this in people. Let's see what happens in mice.'"

So researchers started administering varied levels of finasteride to male lab mice who were put on a high-fat, high-cholesterol "Western"diet for three months.

"Mice that were given a high dose of finasteride showed lower cholesterol levels within the plasma, as well as in the arteries,"said researcher Donald Molina Chaves, a doctoral student at the University of Illinois Urbana-Champaign. "There were also fewer lipids and inflammatory markers in the liver."

However, the effects in mice were only significant at the highest dose of finasteride, a dose that Amengual called "outrageous"for humans. 

Humans take 1 milligram of finasteride a day for hair loss and 5 milligrams daily for an enlarged prostate. By comparison, the mice that showed significant benefits were taking 1,000 milligrams for every kilogram of food they ate.

But the fact that a clear pattern showed in men taking recommended doses for hair loss and enlarged prostate suggests that people don't need the sort of megadoses tested in mice.

The new study was published Feb. 21 in the Journal of Lipid Research.

The next step will be for physicians to start tracking cholesterol in finasteride patients, or to conduct a clinical trial to directly test the potential benefits, the researchers said.

It might be particularly important to understand how finasteride affects transgender individuals, Amengual said.

"Over the past decade, doctors have started prescribing this drug for individuals transitioning either from male to female or female to male,"Amengual said. "In both cases, the hormonal changes can trigger hair loss."

"The interesting thing is that transgender people are also at a higher risk of cardiovascular diseases,"he noted. "So, this drug could have a potential beneficial effect to prevent cardiovascular disease not only in cis[gender] men, but also in transgender individuals."

More information

The U.S. National Institutes of Health has more about finasteride.

SOURCE: University of Illinois Urbana-Champaign, news release, Feb. 20, 2024