Minoxidil forms compared

Key takeaways

• Topical 5% is the proven, cheap default for men and women. In men 5% beat 2% in 393 men (Olsen 2002); in women a Cochrane review found no 2% versus 5% difference (van Zuuren 2016).
• Foam versus solution: foam is propylene-glycol-free, so it causes less itch and flaking. Once-daily 5% foam matched twice-daily 2% solution in 322 women (+23.9 versus +24.2 hairs/cm2), though the non-inferiority margin was narrowly missed (Blume-Peytavi 2016).
• Higher strengths do not help: 10% was no better than 5% and more irritating in 90 men (Ghonemy 2021).
• Oral is not clearly better. Every direct trial found no significant density difference, including 90 men (Penha 2024), and a 2025 meta-analysis of four RCTs (279 people) found about double the hypertrichosis risk on oral (Sobral 2025).
• Dose: in 100 men, 2.5 mg matched 5 mg over 24 weeks with fewer side effects (Carvalho 2025).
• Sublingual 5 mg matched oral 5 mg in 110 men, with fewer palpitations (0% versus 9.3%) (Sanabria 2025); a phase 3 finished in May 2026 with no results posted.
• Extended-release oral (VDPHL01) was reported by its company to give +30 to +33 versus +7 hairs/cm2 at 6 months in men; it is not peer reviewed (trial record).
• Compounded capsules carry dosing-error risk: twelve severe reactions among about 1,700 prescriptions, one stroke after 1,000 mg instead of 1 mg (Moreno-Arrones 2022).
• Stopping reverses the benefit for every form (Price 1999).

The science

Choosing by profile

• Men, crown thinning: topical 5% foam or solution; add finasteride for more. The combination improved 94.1% of 450 men versus 80.5% on finasteride and 59% on minoxidil (Hu 2015).
• Women: 5% foam once daily or 2% solution twice daily; facial hair is the main limit. Women develop hypertrichosis on oral minoxidil at lower doses than men, and pregnancy and breastfeeding rule it out.
• Hairline and temples: minoxidil can thicken miniaturised hairs but cannot regrow follicles that are gone; the US men's label covers the vertex only (label).
• Curly, coily, thick or dry hair: solutions can leave residue and itch; foam or a lightweight vehicle may suit. No hair-type-specific trials were found.
• Scalp irritation or dandruff: patch testing usually implicates propylene glycol rather than minoxidil, so propylene-glycol-free foam is the usual switch.
• Cat owners: topical minoxidil is toxic to cats; 8 of 62 symptomatic cats died in a poison-centre series (Tater 2021).

What it means by hair profile

See "Choosing by profile". Scalp type, curl pattern and porosity were not stratified in the trials found.

Myths and facts

• Myth: oral minoxidil is far stronger than topical. Fact: direct trials show similar density gains.
• Myth: more minoxidil, faster results. Fact: the US labels say using more will not improve results (label).
• Myth: the initial shed means it is not working. Fact: temporary shedding in the first weeks is common.
• Myth: a SULT1A1 test or booster guarantees results. Fact: the evidence comes mostly from the company that sells them, and tretinoin adds irritation without proven benefit.

Practical recommendations

• Give any form 4 to 6 months before judging it: the men's label says 2 to 4 months for first results, and the women's foam label says some women need at least 6 months (label).
• Use it consistently. Weighing oral minoxidil is a decision for a prescriber: it is off-label, and a 2025 consensus lists contraindications (past pericardial effusion, heart failure, pregnancy) and recommends low starting doses (Akiska 2025).

Bottom line

Start with topical 5% (foam if your scalp itches). Oral, sublingual and extended-release forms mainly offer convenience, not stronger regrowth, and add heart-rate, swelling and body-hair trade-offs. Discuss with a doctor before using oral minoxidil. See minoxidil for the full evidence.