Oral minoxidil:
what the research shows

Why it is used by mouth

Topical minoxidil is the approved form for hair loss, and it must be applied twice a day. A 2021 review gave as the rationale for oral use that many patients follow topical treatment poorly, because of the twice-daily application, hair texture and scalp irritation. Oral use is therefore a second option, not a first-line one.

What the published series show

A 2021 review in the Journal of the American Academy of Dermatology found 17 studies with 634 patients using oral minoxidil as the main treatment for hair loss; androgenetic alopecia was the most studied condition. The authors called it effective and well tolerated for healthy patients. A 2025 systematic review pooled 27 studies with 2,933 patients: 35% had significant improvement, 47% some improvement and 26% stable hair. It has no control group, and its authors concluded that the benefit appeared particularly at doses above 1 mg a day and that more research is needed.

Head to head with topical minoxidil

A 2024 randomized trial enrolled 90 men with androgenetic alopecia; 68 completed 24 weeks of oral minoxidil 5 mg once daily or topical minoxidil 5% twice daily. In the frontal area, terminal hair density differed by 3.1 hairs per cm² (95% CI -18.2 to 21.5, P=.27), which is not significant. On photographs, oral minoxidil was superior on the vertex (24%, 95% CI 0 to 48, P=.04), but not on the other measures; the authors did not find oral superior overall.

A 2025 randomized trial from India compared low-dose oral minoxidil, topical minoxidil and platelet-rich plasma with topical minoxidil in 75 people; 60 completed 32 weeks. A one-grade improvement occurred in 25% on oral and 10% on topical minoxidil (P=0.62). The median increase in terminal hair density was 47.5% on oral and 48% on topical. These differences were not significant.

Safety in the largest series

A retrospective multicenter study of 1,404 patients on low-dose oral minoxidil for at least three months (67.2% women, mean age 43) recorded hypertrichosis in 15.1%, which led to withdrawal in 0.5%. Systemic effects were less common: lightheadedness 1.7%, fluid retention 1.3%, tachycardia 0.9%, and 1.2% stopped for systemic effects. No life-threatening events were recorded. The study had no control group, so it cannot compare the risk with no treatment.

What this does not say

• Oral minoxidil is not approved for hair loss; the trials above are off-label.
• The largest safety series has no control group, and the 2025 pooled analysis is single-arm. Neither shows that it works better than no treatment.
• Most randomized evidence is small and short: 24 and 32 weeks in the two trials above.
• The catalog's combination with biotin was not tested as such; the trials were of minoxidil alone.

Sources

1. 1.Randolph M, Tosti A. Oral minoxidil treatment for hair loss: a review of efficacy and safety. J Am Acad Dermatol 2021;84(3):737-46. Journal of the American Academy of Dermatology
2. 2.Vañó-Galván S et al. Safety of low-dose oral minoxidil for hair loss: a multicenter study of 1404 patients. J Am Acad Dermatol 2021;84(6):1644-51. Journal of the American Academy of Dermatology
3. 3.Liu C et al. Efficacy and safety of oral minoxidil in the treatment of alopecia: a single-arm rate meta-analysis and systematic review. Front Pharmacol 2025;16:1556705. Frontiers in Pharmacology
4. 4.Oral minoxidil vs topical minoxidil for male androgenetic alopecia: a randomized clinical trial. JAMA Dermatol 2024;160(6):600-605. JAMA Dermatology
5. 5.Janaani P et al. Analysing efficacy of low-dose oral minoxidil, topical minoxidil, and platelet-rich plasma with topical minoxidil combination in patients with androgenetic alopecia. Arch Dermatol Res 2025;317(1):421. Archives of Dermatological Research