From the Guidelines
For hair growth, oral minoxidil is typically prescribed at a low dose of 1 mg daily. According to the provided evidence, minoxidil is a direct vasodilator that can be used for hair growth, but the dose range listed is 5-100 mg/day for hypertension treatment 1. However, this dose range is not suitable for hair growth. Most dermatologists start patients at 1 mg daily and may gradually increase to 2.5 mg daily if needed and tolerated.
Key Considerations
- The medication should be taken consistently at the same time each day, and results typically take 3-6 months to become noticeable.
- Oral minoxidil works by widening blood vessels, which increases blood flow to hair follicles and prolongs the growth phase of the hair cycle.
- It's essential to be aware of potential side effects, including fluid retention, increased heart rate, unwanted body hair growth, and rarely, more serious cardiovascular effects.
Monitoring and Precautions
- Blood pressure monitoring is recommended, especially when starting treatment.
- This medication requires a prescription and should only be used under medical supervision, as the dose for hair growth is much lower than doses used for blood pressure treatment.
- If you experience dizziness, rapid heartbeat, or swelling, contact your healthcare provider immediately.
From the Research
Oral Minoxidil Dosage for Hair Growth
- The optimal dose of oral minoxidil for hair growth has not been fully established, but studies have investigated various dosages, including low-dose and high-dose regimens 2, 3, 4.
- A study published in 2020 found that oral minoxidil 5 mg once daily effectively increased hair growth in male patients with androgenetic alopecia, with a significant increase in total hair counts and hair diameter measurements 2.
- Another study published in 2025 evaluated the safety and efficacy of high-dose oral minoxidil (> 5 mg) for the treatment of androgenetic alopecia, and found that it resulted in an overall improvement in hair density, although with variable responses and a higher risk of adverse effects 3.
- A multicenter study published in 2021 found that low-dose oral minoxidil (≤ 5 mg daily) had a good safety profile, with infrequent systemic adverse effects and only 1.7% of patients discontinuing treatment due to adverse effects 5.
- A review of oral minoxidil as a treatment for hair disorders published in 2021 suggested that different dosing regimens have been utilized, varying from 0.25 to 5 mg daily, and that women may require lower doses (0.25-2.5 mg daily) while men may require higher doses (1.25-5 mg daily) for maximal efficacy 4.