Minoxidil

What it is

Minoxidil is a medicine that widens blood vessels. It was first used as a tablet for high blood pressure. Applied to the scalp as a liquid or foam it is a standard treatment for male and female pattern hair loss. Taken as a low-dose tablet for hair loss, it is used off-label in many places, and an extended-release 8.5 mg tablet (VDPHL01) is in Phase 3 trials as a possible approved treatment [1].

What the research says

A 2025 meta-analysis of four randomised trials (279 people, 24 to 39 weeks) found oral and topical minoxidil gave similar hair density and hair diameter in androgenetic alopecia [2]. A 2024 trial in 90 men found 5 mg of oral minoxidil a day was not better than 5% topical minoxidil twice a day, although photographs favoured the tablet on the vertex [3]. A network meta-analysis of 23 studies estimated that 5 mg a day of oral minoxidil added about 30 terminal hairs per cm² at 24 weeks compared with topical minoxidil, but that is an indirect comparison [4]. A pooled analysis of 27 mostly uncontrolled studies (2,933 people) reported significant improvement in 35% of people [5].

In October 2026 the developer of VDPHL01 announced topline results from two Phase 3 studies in men (536 and 519 participants), with hair counts rising roughly 29 to 36 hairs per cm² at 6 months versus about 7 on placebo. These come from company announcements and have not been published or peer reviewed (see the registered trials).

Doses used in studies

Published studies used 0.25 mg to 5 mg a day, once or twice daily [1]. A meta-analysis of single-arm studies suggested benefit was clearer above 1 mg a day [5]. The investigational extended-release tablet is 8.5 mg, taken once or twice a day in the trials. These are doses used in research, not recommendations.

Safety and interactions

Common side effects. Hypertrichosis (extra hair growth on the face or body) is the most common; it was about twice as likely with oral as with topical minoxidil [2] and affected 22 of 45 men (49%) in one trial, along with headache in 14% [3]. Hypertrichosis led to about a third of discontinuations in a pooled analysis [6]. Postural low blood pressure is also reported [1].

Blood pressure and heart. At 5 mg a day or less, a meta-analysis found no significant change in blood pressure, a small rise in heart rate (about 2.7 beats per minute) and symptoms of low blood pressure in 5.0% of people; most studies lacked control groups [6]. The Phase 3 programme for VDPHL01 excluded people with uncontrolled blood pressure and certain heart or thyroid conditions, according to the trial registry.

Upper limits and interactions. The reviewed abstracts gave no upper intake limit and no interaction data. Because minoxidil lowers blood pressure, people taking blood-pressure medicines should ask a doctor first.

Pregnancy and breastfeeding. No data were found in the studies reviewed here. Ask a doctor.

Other conditions. No kidney or liver data were found in the studies reviewed here.

Caveats and open questions

Direct trials show no clear advantage over topical minoxidil, while the indirect network analysis suggests one, so the size of the benefit is uncertain [2][4]. Much of the oral evidence is uncontrolled [6][5]. The largest placebo-controlled results are unpublished company announcements covering 6 months of a 52-week study; 12-month safety data are expected later. A female pattern hair loss trial is still running (NCT07146022).