Topical minoxidil is an FDA-approved treatment for male and female pattern hair loss, also known as androgenic alopecia (AGA). Despite its popularity, most people who start on Minoxidil will quit this medication six months after starting due to a poor response rate.
Is Minoxidil the best treatment for male pattern hair loss? We take a look at the science.
What is Minoxidil
Minoxidil was originally approved by the FDA as an anti-hypertensive. Its discovery for the treatment of hair loss was accidental due to reported unwanted hair growth.
How does Minoxidil work?
The exact mechanism of Minoxidil for the treatment of hair loss is still uncertain. It is thought that minoxidil works by stimulating blood flow and improving circulation by opening potassium ion channels.
What are the side effects of Minoxidil?
The nuances of Minoxidil are more likely to be seen with oral Minoxidil compared to topical Minoxidil. However, systemic absorption can also occur with topical Minoxidil at high concentrations. Some of the reported adverse effects from Minoxidil include:
- Mood changes and reduce zest for life - Minoxidil is found to increase the hormone prolactin. Prolactin has the opposite effect of dopamine.
- Gynacomastia - Although rare, Gynacomastia (man boobs) can also be associated with oral Minoxidil if serum levels are high enough. Gynacomastia is a result of high levels of Prolactin. In very rare cases, milk let down can occur (now this is serious stuff and you need a second opinion if this happens for a guy).
- Dizziness, hypotension and ankle swelling
- Irritation and dryness of the scalp from topical formulation
Please note, the side effects for oral minoxidil listed above appear serious but they are extremely rare.
What is the response rate of Minoxidil?
The response rate of topical Minoxidil is found to be approximately 40-60%. Response rate is defined as the percentage of people who tried Minoxidil and saw an improvement in hair count or reduction in hair shedding versus placebo (no drug).
Minoxidil is administered as a pro-drug and requires an enzyme called Sulfotransferase to convert inactive Minoxidil to its active form. This enzyme is found in the hair follicles and also in the liver. Replicated studies confirmed the presence of Sulfotransferase activity in plucked hair follicles predicts treatment response to Minoxidil with 93% sensitivity. The study also reported that for almost half of the people who tried topical Minoxidil, there was little response due to a deficiency of the enzyme Sulfotransferase.
Is Minoxidil the best treatment for hair loss in men?
When comparing the side effect profile of Minoxidil against other prescription medications, topical Minoxidil posses to be a good starting point for male pattern hair loss. If Minoxidil didn't work for you, there are several reasons including:
1. Lack of ability to convert Minoxidil to its active form
Minoxidil is a pro-drug and only becomes active once it comes into contact with an enzyme present in the hair follicle called Sulfotransferase. A study found that approximately 50% of the population do not make enough of this enzyme to see appreciable improvements with Minoxidil.
2. Hormone Imbalance
High levels of DHT causes hair follicles to miniaturise with each new cycle. Minoxidil works by stimulating blood flow to the scalp area to stimulate new growth and does not have any effect on DHT levels. Therefore, you may experience new growth with Minoxidil but the hair strand can remain looking thin.
Studies have also shown micro-needling can improve hair thickness as well as hair count. When used in conjunction with Minoxidil, the results are superior compared to either therapy alone.
3. High alcohol content
Traditional topical Minoxidil formulations contain 30% to 75% alcohol. This can cause scalp dryness and irritation with regular use. The hair strands can also become dry and brittle and break easily.
How long does the effect of minoxidil last?
Studies have found Minoxidil can improve hair weight and hair count by 20-30% from baseline over 52 weeks. This modest increase in hair count is described as cosmetically significant in the eyes of the users. Note the key term is cosmetically significant. In cosmetic clinical studies, it is important to look at the results on a microscopic level and also through the visual lens of the person.
What is Our Experience with Minoxidil
Topical Minoxidil is an effective treatment for androgenic alopecia in men and women. Topical formulations have the benefit that they produce a good response rate with less side effects compared to oral minoxidil. Choosing a formula without alcohol is key especially when considering Minoxidil as a long term treatment.
Author: Dan Atkinson B Pharm
- American Academy of Dermatology. “What is Male Pattern Hair Loss and can it be Treated?” News release Updated December 13, 2022. Last accessed June 5, 2023.
- Olsen, E et al. (2002). "A randomized clinical trial of 5% topical minoxidil versus 2% topical minoxidil and placebo in the treatment of androgenetic alopecia in men." Journal of the American Academy of Dermatology, 47(3), 377 385.
- Roberts, J et al (2014). "Response to Topical Minoxidil in Female Androgenic Alopecia." Journal of Dermatologic Therapy. Jul-Aug;27(4):252-4