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Finasteride, a common drug used to treat hair loss and enlarged prostate, may also help lower cholesterol levels and reduce the risk of heart disease. stefanamer/Getty Images
  • A new study has found that finasteride may be able to reduce cholesterol levels.
  • The drug is currently used for male pattern baldness and enlarged prostate.
  • Men taking the drug had lower cholesterol levels than those who didn’t.
  • Mice given finasteride had reduced cholesterol levels as well.
  • However, more research is needed to see if it is safe and effective.

The drug finasteride, available under the brand names Proscar and Propecia, is currently used for male pattern baldness and enlarged prostate in men.

Finasteride works by stopping testosterone from being converted into dihydrotestosterone (DHT). This slows down hair loss and prevents the prostate from growing too large.

However, a study published in the March 2024 issue of the Journal of Lipid Research suggests that there might be yet another application for this medication: lowering artery-clogging cholesterol.

In addition to being associated with lower cholesterol levels in men, the drug was also found to reduce cholesterol, delay atherosclerosis, and lower liver inflammation in mice.

The idea for the study first came about when the lead author, Jaume Amengual, PhD, became curious to learn about the long-term effects of finasteride.

After examining data from the National Health and Nutrition Examination Survey (NHANES) that was collected between 2009 and 2016, Amengual found, on average, that the men who were taking the drug had cholesterol that was about 30 points lower than those men who weren’t taking it.

Unfortunately, there was nothing in the data to tell him what dose the men had been taking or for how long. This led him to set up a study with mice.

In this study, mice were treated with four different amounts of finasteride: 0, 10, 100, and 1,000 milligrams per kilogram of food. The drug was given to mice that were genetically prone to developing atherosclerosis.

Additionally, the animals were fed a high fat, high cholesterol diet mimicking a typical Western diet consumed by humans.

After 12 weeks, the mice had their lipids tested and were examined for evidence of atherosclerosis. They were also tested for gene expression in the liver.

The researchers additionally looked at bile acid metabolism and tested the mice for steroids, triglycerides, and immune activity.

After performing the tests, they found that the mice that were given finasteride had lower cholesterol levels, both in their plasma and in their arteries.

They also had lower lipid levels and inflammatory markers.

Amengual did note in a press release that the amount needed to achieve this result was “incredibly high.” However, he explained, mice tend to be more resistant to drugs than humans are. This, combined with the fact that men in the NHANES database also saw reduced cholesterol levels, suggests that humans would respond to a lower dose than the mice did.

Rigved Tadwalkar, MD — a board certified consultant cardiologist at Providence Saint John’s Health Center in Santa Monica, California, who was not involved in the study — stated that there are a few potential ways that finasteride might benefit human cholesterol levels.

“One proposed mechanism suggests that finasteride could reduce monocyte activity and inflammation, thereby diminishing the number of monocytes, which are immune cells that are involved in the formation of arterial plaques,” he explained.

“Another avenue explored is the modulation of bile acid metabolism by finasteride, hinting at its potential to influence the production and excretion of bile acids, consequently impacting cholesterol metabolism.”

Tadwalkar additionally noted that the study delved into the possibility that finasteride changes hepatic gene expression.

These alterations might be able to extend to lipid metabolism and inflammation in the liver, he said.

Justin Manjourides, PhD — a biostatistician and Associate Professor of Biostatistics at Northeastern University who was not a part of the research — commented on the study, saying, “My initial thoughts are that this is a fairly well-done study.”

Although the key results are in mice, they are consistent with what was observed in humans, he pointed out.

“By motivating the observational portion of the study on the experimental mouse data, the authors sidestep the common ‘p-hacking’ critique where several exposure-outcome pairs are examined and only those reaching significance are presented.”

Further, reduced cholesterol levels were consistent across several potential effect modifiers, said Manjourides.

He went on to note that the NHANES portion of the study had several limitations, including the fact that it only included 155 men.

“With respect to finasteride, there are no measures of dosage, adherence, or duration of treatment,” he added.

“In a cross-sectional study, lacking information on duration of treatment or information on baseline outcome measures (pre-finasteride exposure) hinders our ability to establish a causal relationship between the exposure and outcome.”

Manjourides also remarked that there are potential issues with the underlying differences between those who used finasteride and those who didn’t.

“There is no way to tell in which direction a bias caused by lacking this information would be,” he concluded.

While these findings are promising, Tadwalkar said it’s too early to say how well finasteride might compare with other established cholesterol-lowering medications, such as statins, ezetimibe, and PCSK9 inhibitors.

These drugs have proven efficacy in lowering cholesterol and reducing cardiovascular risk, he said.

“While the study suggests a potential benefit of finasteride in delaying cardiovascular disease by improving the plasma lipid profile, the benefits should be considered in the context of existing interventions,” said Tadwalkar.

“More research is needed to determine its true efficacy, safety profile, and optimal role in managing cholesterol and cardiovascular disease risk.”

New research suggests that the drug finasteride, currently used to treat male pattern baldness and enlarged prostate, might also be able to reduce cholesterol, thereby reducing the risk for cardiovascular disease.

Men using the drug had lower cholesterol levels.

Finasteride was also found to reduce cholesterol levels in mice.

However, while the findings of the study are promising, it’s too soon to say how well it might compare with existing therapies. More research is needed to show whether finasteride is safe and effective for reducing cholesterol in humans.