The Benefits and Risks of Low Dose Oral Minoxidil are Dose Dependent:

Increasing the Dose of Oral Minoxidil Brings A Greater Chance of Success - and Greater Chance of Side Effects.

Low dose oral minoxidil is increasing used to treat various types of hair loss. Typical doses range from 0.25 mg to 5 mg. Generally speaking, any dose under 5 mg is considered low dose oral minoxidil.

Gupta et al 2022

Authors of a new study set out to determine whether to determine whether the safety and efficacy of oral minoxidil is related to the prescribed dose.

 To do so, the authors performed systematic searches in PubMed and Scopus. They found six studies were eligible for quantitative analyses and then conducted meta-regressions.  The authors found that after six months of use in patients with AGA, increasing the dosage of LDOM by 1 mg/day was  significantly associated with:

1) a sex-adjusted increase in hair diameter of 1.4 um (p=0.013)

2) an increased in total hair density of 47.1 hairs/cm2 (p = 0.007)

3) an increase in terminal hair density of 9.1 hairs/cm2 (p = 0.001)

In terms of side effects, the authors found that after six months of use in patients with AGA, increasing the dosage of LDOM by 1 mg/day was associated with:

1) a risk of hypertrichosis by 17.9%, (p = 0.006)

2) a risk of cardiovascular adverse events like hypotension, edema, increased heart rate, palpitation, and abnormal EKG by 4.8% (p = 0.004).

Conclusions:

 All in all this study showed that benefits and risk of oral minoxidil are dose dependent. Increasing the dose increases the likelihood that there will be improvement in density and hair diameter and increases the likelihood that there will be hypertrichosis and cardiovascular side effects too.

REFERENCE

Gupta AK et al. There Is a Positive Dose-Dependent Association between Low-Dose Oral Minoxidil and Its Efficacy for Androgenetic Alopecia: Findings from a Systematic Review with Meta-Regression Analyses. Skin Appendage Disord. 2022 Sep; 8(5): 355–36