Minoxidil vs Finasteride: Do Either Really Work?

Search for information about hair loss drugs and you’ll see two options mentioned frequently: minoxidil and finasteride.

Both drugs have been around for decades and both are widely used to treat hair loss. But do either of them work? If so, which of them is the most effective?

In this post, we’ll look at how minoxidil and finasteride work, how effective they are when used properly, and how each drug compares to the other. We’ll also compare their effects, since both drugs have a slightly different effect on hair loss and the growth of new hair.

Minoxidil vs Finasteride: What’s The Difference?

Minoxidil and finasteride are two of the most popular hair loss treatments on the market. Both are pharmaceutical medications, and both are available either as prescription medicine or as over-the-counter treatments in most countries.

Both minoxidil and finasteride are proven to be effective at preventing hair loss. However, the two drugs work in completely different ways.

How Minoxidil Works

Minoxidil is a vasodilator. This means it widens the blood vessels and increases blood flow in certain areas of the body. Put minoxidil on your scalp and it will relax the muscle walls of the blood vessels, making it easier for blood to flow to your scalp and hair follicles.

This vasodilating effect causes more nutrients and oxygen to flow through your blood to your hair follicles, potentially promoting growth.

Technically, minoxidil doesn’t stop hair loss. Instead, it actively promotes the growth of hair by causing hairs in a resting state (known as the telogen phase) to shed and replacing them with new hairs in the growing (or anagen) phase.

Because of this, one of the most common side effects of minoxidil use is rapid hair loss. This is a temporary effect that happens as your resting hairs shed. Once they’re replaced with hairs in the anagen phase, minoxidil can produce a noticeably thicker head of hair.

Minoxidil is available as a spray, as a liquid, and as a topical foam. It’s also available in a variety of concentrations, letting you apply a heavy or light dose of minoxidil to the areas of your scalp that are affected by hair loss.

How Finasteride Works

Finasteride is a 5α-reductase inhibitor. It prevents hair loss by stopping testosterone from being converted into dihydrotestosterone -- the powerful androgenic hormone that causes damage to hair follicles in men.

The process by which DHT affects hair is quite complicated. If you’d like to learn more, give our Guide to DHT and Male Hair Loss a read -- it explains how DHT is formed and how it causes irreversible damage to male hair follicles.

Finasteride acts like a barrier, preventing your body’s testosterone from converting into DHT. By blocking testosterone from converting into DHT, it reduces your body’s DHT level and stops the hormone from binding to your hair follicles and causing damage.

Because it takes quite a lot of time for DHT to damage your hair follicles, finasteride can even cause mild regrowth in patches of hair that are starting to thin.

Meanwhile, minoxidil exclusively acts as a growth agent, helping your hair grow thicker, faster and better than it normally would. Unlike finasteride, minoxidil has no known effect on DHT or other hormone production.

Do Minoxidil and Finasteride Work?

Put simply, yes. Both minoxidil and finasteride have been scientifically proven to help either stop hair loss or promote hair growth.

Finasteride has been proven to work in numerous studies. A 1998 study from the Journal of the American Academy of Dermatology shows that finasteride produces a measurable increase in hair growth on the scalp, with an average increase of over 15% after two years.

Other studies show a reduction in hair loss and a noticeable increase in hair growth over a year of use. There are even five-year studies showing durable improvements in scalp hair over long periods of time.

There are also numerous studies showing that Minoxidil is effective at promoting hair growth. In a four-month study, 74% of men judged that minoxidil improved their hair density, with 93.8% of study participants judging minoxidil as very effective, effective or moderately effective at stimulating new hair growth.

There is no shortage of hair loss treatments out there built on hype instead of results. However, countless studies show that finasteride and minoxidil are real hair loss treatments that produce real results, especially when taken long term.

Are Minoxidil and Finasteride Safe to Take Together?

Studies show that minoxidil and finasteride are safe to take together. In fact, many studies have been conducted using finasteride and minoxidil together to prevent hair loss while fueling new growth of healthy hair.

A 2015 study in the Indian Dermatology Online Journal shows that use of both finasteride and minoxidil together helps maintain a good hair density level. Interestingly, this study uses topical finasteride instead of the more common oral finasteride tablets.

Finasteride and minoxidil work through different mechanisms -- minoxidil as a vasodilator and finasteride as a 5α-reductase inhibitor that targets DHT. Since they target different parts of the body, there’s no risk in taking them together.

You should always check drug interactions before beginning any hair loss treatment. If you take any other medications, it’s worth talking to your doctor to make sure that they can’t interact with either minoxidil or finasteride.

Minoxidil vs Finasteride: Which is Better?

Minoxidil and finasteride are different medications designed for different purposes. While both prevent hair loss and encourage hair growth, one does it at the topical level while the other is a hormonal medicine that stops hair loss at its source.

Because finasteride stops DHT production, most hair loss doctors will recommend it as a first course of action before using minoxidil. Both drugs are also commonly used together to get a stronger, more noticeable effect.

At the end of the day, the best option for hair loss depends on your personal needs. If you’re interested in stopping your hair loss using finasteride or minoxidil, complete an online consultation with our expert hair loss doctors to learn more about your options.

Article reviewed by Brendan Levy, MD.