How Does Minoxidil Work?
Minoxidil was originally developed in the 1970s as a blood pressure medication. During clinical use, doctors discovered a surprising side effect: increased hair growth. This discovery led to the development of topical minoxidil, which was approved by the FDA for hair loss treatment in 1988. For a comprehensive application guide, read our article Minoxidil Application.
The exact mechanism of action is not yet fully understood, but several factors play a role. Minoxidil dilates blood vessels in the scalp, improving blood flow to hair follicles (vasodilation). It also extends the anagen phase, the growth phase of hair. Miniaturized follicles can produce larger, stronger hairs again through treatment. Additionally, minoxidil activates important signaling pathways and growth factors in hair roots.
Efficacy
Clinical studies consistently show positive results. At 48 weeks of use with the 5% solution, 45% of men showed moderate to dense hair regrowth. [2] The 5% concentration is approximately 45% more effective than the 2% concentration. The combination with finasteride is more effective than either ingredient alone. Start your online consultation now or learn about our treatment options.
Efficacy depends on an enzyme called sulfotransferase (SULT1A1), which converts minoxidil to its active form. About 40% of people have lower enzyme activity and therefore respond less well to topical minoxidil. [1] Minoxidil is particularly effective for androgenetic alopecia.
Application
For topical application, the scalp should be dry. Apply 1 ml solution or half a cap of foam to affected areas and massage gently for about 30 seconds. The product should be left on for at least 2 hours before washing your hair. Don't forget to wash your hands after application.
Oral minoxidil is used in low doses (0.25-5 mg) for hair loss. It is particularly suitable for people who don't respond to topical minoxidil, those with low SULT1A1 activity, or when simpler application is preferred. Oral use requires medical supervision and regular check-ups. [3]
Approved Uses
- Androgenetic alopecia (hereditary hair loss)
- Diffuse hair loss
- Post-hair transplant support
Drug Category
VasodilatorDosage
| Form | Strength | Frequency | Prescription Required |
|---|---|---|---|
| Topical (Solution/Foam) | 2-5% | 1-2x daily | No |
| Topical (Compounded) | 7-10% | 1x daily | Yes |
| Oral (Tablet) | 0.25-5 mg | 1x daily | Yes |
Side Effects
Common Side Effects
- Scalp irritation
- Dry scalp
- Initial shedding (temporary increased hair loss)
- Flaking
Uncommon Side Effects
- Increased facial hair growth (hypertrichosis)
- Contact dermatitis
- Headaches
Rare Side Effects
- Dizziness
- Rapid heartbeat (tachycardia)
- Fluid retention (edema)
- Weight gain
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Start nowNot suitable for
- Hypersensitivity to minoxidil or excipients
- Pregnancy and breastfeeding
- Pheochromocytoma
- Severe cardiovascular disease (for oral use)
Warnings & Precautions
Do not apply topical minoxidil to irritated, inflamed, or injured scalp
Regular monitoring of blood pressure and heart rate required for oral use
Initial shedding in the first 4-6 weeks is normal and not a reason to stop
Effects can only be assessed after 3-6 months of regular use
Hair loss returns after discontinuation
FAQs
References
- [1] Suchonwanit P, Thammarucha S, Leerunyakul K. (2019). Minoxidil and its use in hair disorders: a review. Drug Design, Development and Therapy. https://doi.org/10.2147/DDDT.S214907
- [2] Olsen EA, Dunlap FE, Funicella T, et al.. (2002). A randomized clinical trial of 5% topical minoxidil versus 2% topical minoxidil and placebo. Journal of the American Academy of Dermatology. https://doi.org/10.1067/mjd.2002.124088
- [3] Randolph M, Tosti A. (2021). Oral minoxidil treatment for hair loss: A review of efficacy and safety. Journal of the American Academy of Dermatology. https://doi.org/10.1016/j.jaad.2020.06.1009