Intermittent Daily Isotretinoin Matches Alternate-Day Regimen in Grade 2 Acne Trial
Key Takeaways
- In a randomized, single-blinded non-inferiority trial, intermittent daily isotretinoin (30 mg daily for 1 week per month) was non-inferior to continuous alternate-day isotretinoin (20 mg every other day) for grade 2 facial acne vulgaris.
- Significant clinical response rates were similar between regimens (93.3% vs 96.7%), with comparable adverse event profiles and no relapse to pretreatment acne scores during follow-up.
- The intermittent daily regimen was associated with lower treatment cost, suggesting a potentially more economical low-dose isotretinoin strategy for moderate acne.
A randomized controlled trial published in the Indian Journal of Medical Research found that an intermittent daily isotretinoin regimen was non-inferior to a continuous alternate-day regimen for the treatment of grade 2 facial acne vulgaris, while also offering lower treatment costs.¹
Researchers Chingshubam Bikash, Shikha Verma, and Anita Marak conducted a randomized, single-blinded, non-inferiority trial involving 60 patients aged 18 years and older with grade 2 facial acne. Participants were randomized to receive either isotretinoin 20 mg on alternate days (Group A) or isotretinoin 30 mg daily for 1 week each month over a 4-month treatment period (Group B).¹
Fixed-Dose Isotretinoin Regimens Show Comparable Efficacy in Moderate Acne
Both treatment groups experienced substantial reductions in acne burden. Mean acne load decreased from 22.60 ± 10.0 to 5.63 ± 4.87 in the alternate-day group and from 28.70 ± 18.10 to 5.63 ± 4.87 in the intermittent daily group.¹
The proportion of patients achieving a significant clinical response was 96.7% in the alternate-day cohort and 93.3% in the intermittent daily cohort (P = 0.28), meeting predefined non-inferiority criteria. Investigators reported a progressive reduction in acne load over the course of treatment, with increasing effect size as therapy continued. No relapse to pretreatment acne scores was observed during the study period.¹
Adverse events were comparable between groups, and no major differences in tolerability were identified. However, treatment costs were significantly higher among patients receiving the alternate-day regimen.¹
Study limitations include the relatively small sample size and single-center design, which may affect generalizability. Longer follow-up studies will be needed to better characterize relapse rates following treatment discontinuation.
“The daily intermittent regimen is non-inferior to alternate day regimen at fixed dosages in significantly improving grade 2 facial acne vulgaris with similar side effect profiles,” the authors wrote. “The daily intermittent regimen, also with a lower cost, is thus preferrable.”¹
Reference
- Bikash C, Verma S, Marak A. Continuous alternate day vs intermittent daily fixed doses of oral isotretinoin in grade 2 acne vulgaris. Indian J Med Res. 2026;163(6):731-737. doi:10.25259/IJMR_2458_2025