From the Research
Oral minoxidil is a highly effective treatment for androgenic alopecia, acting as a potassium channel opener that dilates blood vessels in the scalp, increasing blood flow to hair follicles, and promoting hair growth. This improved circulation delivers more oxygen and nutrients to the follicles, prolonging the anagen (growth) phase of the hair cycle and shortening the telogen (resting) phase. The medication converts inactive hair follicles to active ones and increases the diameter of existing hair shafts, as supported by a systematic review evaluating the use of oral minoxidil for all types of alopecia 1. Typically prescribed at low doses of 0.25-5mg daily, oral minoxidil also stimulates prostaglandin synthesis and increases expression of growth factors like VEGF, promoting hair growth 2. Results typically appear after 3-6 months of consistent use, with maximum benefits seen around 12 months. Side effects may include increased body hair growth, fluid retention, and rarely, cardiovascular effects like tachycardia or hypotension, especially at higher doses, as reported in a multi-center, retrospective analysis 3. Regular monitoring by a healthcare provider is recommended, particularly when starting treatment. Some key points to consider when using oral minoxidil for androgenic alopecia include:
- The strongest evidence exists for androgenetic alopecia and alopecia areata, with 61-100% and 18-82.4% of patients demonstrating objective clinical improvement, respectively 1
- Oral minoxidil is a safe and successful treatment of androgenic alopecia, with practical advantages over topical minoxidil stemming from improved patient compliance 1
- A probable efficacy ranking, in decreasing order, is dutasteride, finasteride, and minoxidil, with oral minoxidil predominantly causing hypertrichosis and cardiovascular system symptoms/signs in a dose-dependent manner 2
- The average plasma half-lives of minoxidil, finasteride, and dutasteride are ∼4 h, ∼4.5 h, and ∼5 weeks, respectively, with minoxidil acting through multiple pathways to promote hair growth, including as a vasodilator, an anti-inflammatory agent, a Wnt/β-catenin signaling inducer, and an antiandrogen 2.