Minoxidil: A Revolutionary Hair Loss Treatment

Many people know that minoxidil helps treat hair loss. But what was the treatment originally used for? And how did scientists discover it could regrow hair? We reveal all below.

Updated: Thursday 13 January 2022

Anyone who is familiar with Regaine will know it is used to treat hair loss. It contains the active ingredient, Minoxidil, a vasodilator. When applied to the scalp, the treatment widens blood vessels. This encourages blood flow to the hair follicles, which increases the size and the diameter of the hair shaft - encouraging hair to grow back thicker in areas where it was previously thinning.

The clinical efficacy of minoxidil is well-documented. More than two-thirds of men find the treatment effective when used properly, and it is most effective in people who have only recently started to lose their hair. Regaine may be used in combination with oral medications by men wishing to maximise hair regrowth. But minoxidil was not initially developed to treat hair loss at all. In fact, it would be years after its development when scientists and doctors realised minoxidil had the ability to regrow hair.

Humble beginnings

For many, a treatment that can actually promote hair growth might sound like something from a sci-fi novel (or an episode of the Simpsons). But minoxidil was actually discovered almost 60 years ago.

In the 1950s, the Upjohn Company - a pharmaceutical manufacturer that later became part of Pfizer - developed a new chemical compound intended to treat ulcers. But scientists’ hopes were quickly dashed. In animal trials, researchers found that the compound didn’t cure ulcers. They did, however, notice something else: the compound lowered blood pressure.

Upon discovering a new application for the drug, Upjohn synthesized more than 200 variations of the compound. Among these was minoxidil, which they synthesized and named in 1963. Upjohn took its findings to the US Food and Drug Administration (FDA), which granted the company permission to trial the drug as an oral treatment for high blood pressure.

Curious side effects

Around eight years after the FDA gave Upjohn the green light to trial minoxidil, one of the regulator’s consultants noticed something curious. In 1971, Dr. Charles A. Chidsey found that patients who had taken the treatment for hypertension had an odd side effect: hair growth. Intrigued, Dr. Chidsey asked two colleagues for advice: Dr. Guinter Kahn, and his medical resident, Dr. Paul J. Grant.

After examining the patients - amongst which was a woman growing hair all over her body - Dr. Kahn and Dr. Grant decided to investigate further. After administering minoxidil to other test subjects, they found the same result: more hair started growing on their bodies. Dr. Kahn was reported to have said right off the bat, “Boy, this would be great stuff if we could apply it to the top of heads.”

So that’s exactly what the two doctors set out to do. They immediately began working on converting oral minoxidil into a topical solution that patients could use directly on their scalps. But it was important that they get it right. Too little minoxidil in the solution would render the treatment ineffective. Too much could produce negative side effects.

With a stroke of luck, however, Dr. Grant and Dr. Kahn got the solution right pretty much straight away - and on 10 December, 1971, they travelled to Upjohn’s headquarters in Michigan, US to brief scientists and executives on their findings.

‘A gold mine’

In their meeting with Upjohn’s top brass, Dr. Kahn was enthusiastic about their discovery - even going so far as to call it a potential “gold mine”. The pair even demanded a 2-4% stake in all Upjohn products sold containing a topical minoxidil, but the company’s executives never directly answered them.

Around two and a half weeks later, Upjohn filed a formal patent application for minoxidil as a hair growth treatment - and named Dr. Chidsey as the sole inventor. The company informed the FDA that Dr. Kahn and Dr. Grant had experimented with minoxidil for purposes that hadn’t been approved by the regulator.

Upjohn, however, didn’t tell the doctors it had applied for a patent. Dr. Khan and Dr. Grant only found out about it two years later, when after testing minoxidil on a balding person to wondrous results, they tried to file one of their own. The FDA told them Upjohn had already applied to patent the same drug for the same purpose - to which the doctors responded that they were the ones who had informed Dr. Chidsey and the company of their successes before the patent was filed.

The two parties agreed to let the patent office decide on the issue. In the meantime, Upjohn settled the financial aspects of the dispute with Dr. Kahn and Dr. Grant, offering them substantial royalties alongside Dr. Chidsey.

The legal battle to change the patent, however, took much longer. It wasn’t until 1986 that the patent office agreed to add Dr. Kahn’s name to the patent - and even then, Dr. Grant’s name was still left off. Thankfully, Dr. Grant didn’t seem to mind very much. “I’d be much more upset if they took my name off the royalties,” he told the Miami Herald in 1988.

Upjohn ended up spending $100 million developing Regaine, which was approved by the FDA in 1988. Its patent expired in 1996, allowing other manufacturers to develop and sell minoxidil over the counter under other brand names.

Minoxidil was the first clinically-proven treatment for hair loss. At the time, it was revolutionary. In 1984, however, Merck patented finasteride, which was approved for medical use by the FDA in 1992. They both remain the only hair loss treatments clinically proven to stop male-pattern baldness, and in some instances even regrow hair.