Hair Loss in Patients With Acne: Low vs High Dose Isotretinoin

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The frequency of hair loss in patients with acne vulgaris on a low vs higher daily dose of isotretinoin is assessed.

Among patients with acne vulgaris treated with isotretinoin, fewer patients on a low-dose suffered hair loss than patients on a higher dose, according to study findings published in the Journal of The American Academy of Dermatology International.

Hair loss is a known side-effect of isotretinoin and potentially troubling for teenage patients, the most likely recipient of the treatment, the investigators wrote. Understanding of the factors surrounding this potential side-effect—dose dependency, occurrence rate, reversibility of hair loss—could help clinicians with patient counseling and decision making.

To accomplish this, in July 2020 they conducted a systematic review of 22 studies found in Embase and MEDLINE, that reported hair loss for patients treated with oral isotretinoin. The studies included 565 patients with acne (mean age, 22 years; 63.7% men) treated with isotretinoin therapy less than 0.5 mg/kg/d, and, 3375 patients with acne (mean age, 22.4 years; 60.7% men) treated with isotretinoin therapy 0.5 mg/kg/d or greater.

In the low dose cohort, the mean weight-based dose was 0.24 mg/k/d, administered for an average of about 4 months, and 3.2% of patients reported hair loss. In the higher dose cohort, the mean weight-based dose was 0.59 mg/k/d, administered for an average of about 6.5 months, and 5.7% of patients reported hair loss.

Study limitations included a statistical analysis not being feasible to compare the 2 cohorts; also, most of the 22 studies used were not randomized, limiting the comparison of negative effects. Also, there was a lack of data for comparisons between male and female hair loss and for confounding variables. Finally, most outcomes were self-reported and not clinically documented.

Researchers concluded that lower dosing isotretinoin (<0.5 mg/kg/day) led to 3.2% frequency of hair loss and higher dosing isotretinoin (≥0.5 mg/kg/day) led to 5.7% frequency of hair loss. They suggested, “Physicians should consider counseling patients about the risk of telogen effluvium prior to drug initiation, as is commonly done for other side effects. The potential trend of increased hair loss frequency at a higher daily dosing warrants further investigation using higher-quality research.”


Lytvyn Y, McDonald K, Mufti A, Beecker J. Comparing the frequency of isotretinoin-induced hair loss at <0.5-mg/kg/d vs ≥0.5-mg/kg/d dosing in acne patients: A systematic review. JAAD Int. Published online February 10, 2022. doi:10.1016/j.jdin.2022.01.002