Oral minoxidil may be a viable alternative to topical treatment for male pattern baldness

Low-dose oral minoxidil demonstrates comparable efficacy to 5% topical minoxidil in the treatment of androgenetic alopecia in men, offering a viable option for those who prefer oral therapy or those who poorly tolerate topical treatment, as shown in a study.

After 24 weeks of treatment, participants who received oral minoxidil at 5 mg, once daily, saw improvements in terminal and total hair density, although these improvements were not necessarily better than those observed in participants who received 5% topical minoxidil.

For the frontal area, the mean change from baseline in terminal and total hair density differed by 3.1 hairs per cm² (95 percent confidence interval [CI], −18.2 to 21.5) and 2.6 hairs per cm² (95% CI, −10.3 to 15.8), respectively, between the oral and topical minoxidil arms (p=0.27 and p=0.32, respectively). [JAMA Dermatol 2024; doi:10.1001/jamadermatol.2024.0284]

For the vertex area, the corresponding differences were 23.4 hairs per cm² (95 percent CI, −0.3 to 43.0) for terminal density (p=0.09) and 5.5 hairs per cm² (95 percent CI, −12.5 to 23.5) for total hair density (p=0.32).

However, in hair count analyses from photographs, oral minoxidil showed superiority over topical minoxidil on the vertex scalp (24 percent, 95 percent CI, 0–48; p=0.04) but not on the frontal scalp (12 percent, 95 percent CI, −12 to 36; p=0.24).

As for safety, both oral and topical minoxidil were well tolerated. The most frequent adverse effects were hypertrichosis and headache, the rates of which were significantly higher in the oral minoxidil group (49 percent vs 24 percent and 14 percent vs 2 percent, respectively; p=0.02 and p=0.046). On the other hand, more participants in the topical minoxidil group experienced local effects such as itching on the scalp (2 percent vs 11 percent; p=0.09) and scalp eczema (2 percent vs 16 percent; p=0.02).

“There were no significant changes in heart rate and blood pressure in the oral minoxidil group, endorsing its negligible hypotensive potential for healthy individuals,” the investigators noted. [J Am Acad Dermatol 2023;88:436-437]

“Furthermore, it is known that minoxidil may cause transient hair loss in the first 2 months of treatment due to the early release of hairs in the telogen phase (premature teloptosis)… In our study, this happened in 16 percent of patients in the topical minoxidil group and only 9 percent in the oral minoxidil group,” they said, highlighting the importance of informing patients about the transient and self-limited nature of hair loss to prevent early treatment interruption.

In recent years, low-dose oral minoxidil has become a promising alternative to topical minoxidil for individuals with androgenetic alopecia. According to the investigators, the oral formulation addresses the issues associated with the topical formulation and reduces the risk of sexual side effects when compared with 5α-reductase inhibitors. [Hair Transplant Forum Int 2023;33:93-94; An Bras Dermatol 2020;95:271-277]

The findings of the present study are in line with that of a prior noncomparative prospective study, which showed that oral minoxidil 5 mg, once per day, helped increase hair density in men with androgenetic alopecia over 24 weeks. Specifically, nonvellus hair density increased by 35.9 hairs per cm² (23.6 percent), while total hair density increased by 35.1 hairs per cm² (19.2 percent) on the vertex region. [Dermatol Ther 2020;10:1345-1357]

The current study included 68 men with androgenetic alopecia (mean age 36.6 years). These men were randomly assigned to receive oral minoxidil 5 mg daily and topical placebo solution (n=33) or 1 mL of 5% topical minoxidil twice daily and oral placebo (n=35) for 24 weeks. Both groups were homogenous in terms of demographic data and androgenetic alopecia severity (Norwood-Hamilton scale grade 3V: 53 percent vs 60 percent, respectively).

“Further larger clinical trials with longer follow-up times are needed to compare different doses of oral minoxidil as well as its use with topical minoxidil or 5α-reductase inhibitors,” the investigators said.