Three Drugs Repurposed for Treating Hair Loss and Erectile Dysfunction

Medical discoveries do not always follow their initial intended path, as some drugs developed for specific diseases have later been found to be more effective in treating entirely different conditions. This approach, known as "drug repurposing," has contributed to providing effective and more affordable treatments for various health issues.

In men's health, three drugs exemplify this phenomenon by shifting from their original uses to become common treatments for erectile dysfunction and hair loss: sildenafil, finasteride, and minoxidil.

From Chest Pain Treatment to Erectile Dysfunction Medication

In the early 1990s, researchers were testing sildenafil as a treatment for angina pectoris, a condition caused by reduced blood flow to the heart muscle. The drug works by relaxing blood vessels and improving blood flow through inhibition of an enzyme called phosphodiesterase type 5 (PDE5).

Although sildenafil's results in treating angina were not as promising as hoped, clinical trial participants reported noticeable improvements in erectile function. This unexpected finding led to the development of the first oral treatment for erectile dysfunction, launched in 1998 under the brand name Viagra, which became one of the most well-known drugs worldwide.

Sildenafil is now also used to treat pulmonary arterial hypertension, a rare disease affecting blood vessels in the lungs. Its side effects are generally mild, including headache, facial flushing, and nasal congestion, but it may interact with certain heart medications, necessitating medical consultation before use.

Prostate Medication That Stimulates Hair Growth

Finasteride was originally developed to treat benign prostatic hyperplasia, a common condition in aging men characterized by prostate enlargement. The drug reduces levels of dihydrotestosterone (DHT), a hormone that stimulates prostate growth.

During clinical trials, researchers observed that some patients experienced reduced hair loss and even new hair growth. This discovery prompted further testing of finasteride for treating male pattern baldness, eventually making it one of the most widely used treatments for hair loss.

Finasteride helps protect hair follicles from hormonal effects that cause gradual shrinkage, aiding in hair preservation and stimulating growth in some users. Despite its effectiveness, it may cause uncommon side effects such as decreased libido or erectile difficulties, and some users have reported psychological symptoms like depression.

Blood Pressure Drug Repurposed for Hair Loss Treatment

Minoxidil was initially used in the 1960s to treat severe hypertension. During its use, doctors noticed hair growth in some patients, including in areas where hair typically did not grow.

This effect attracted researchers' attention, leading to the development of a topical form of minoxidil applied directly to the scalp, which was later approved for treating hair loss.

Minoxidil is believed to stimulate hair follicles by improving blood flow and extending the normal hair growth phase, increasing hair density in some individuals. Some users may experience a temporary increase in hair shedding during the first weeks of treatment, which is generally a normal sign of a new hair growth cycle starting.

Today, minoxidil is among the most common treatments for hair loss in both men and women, with side effects typically limited to scalp irritation or dryness.

Researchers suggest that major medical discoveries may not always stem from creating new drugs but rather from identifying new uses for existing ones. Many medications may still hold untapped potential awaiting discovery.

This report was prepared by Deepa Kamdar, Senior Lecturer in Pharmacy Practice at Kingston University.