Real-World Safety of Oral Isotretinoin During Sunny Months

<h2 id="background">Background</h2><ul><li>Oral isotretinoin administration is commonly withheld during sunny seasons due to perceived photosensitizing effects, yet this practice lacks robust clinical evidence.</li></ul><h2 id="objectives">Objectives</h2><ul><li>To evaluate safety and efficacy of reduced-dose oral isotretinoin administered during sunny months (June- September) in a real-world clinical setting.</li></ul><h2 id="methods">Methods</h2><ul><li>Retrospective cohort analysis of acne patients receiving oral isotretinoin at an Acne Clinic (2014-2023) with exposure during high UV periods (UV index&gt;6).</li><li>Standard practice involved 50% dose reduction during sunny months.</li><li>Adverse event occurrence and treatment discontinuation rates were compared between sunny and non- sunny periods. Acne response was assessed relative to daily dosage.</li></ul><h2 id="results">Results</h2><ul><li>359(61.3% male; mean age 19.0±6.7 years) were analyzed.</li><li>Adverse events occurred in 39.2% and 28.3% of observations during non-sunny and sunny periods, respectively (p&lt;0.001) as shown in Table.</li><li>Treatment discontinuation rates were comparable between periods (p=0.999).</li><li>Acne severity reduction was dosage-independent.</li></ul><figure class="image"><img style="aspect-ratio:1132/280;" src="https://cdn.megawecare.com/GHBY/Internal-Images/oral-isotretinoin-daily-dose.webp" alt="Oral Isotretinoin Daily Dose, Adverse Events, and Treatment Discontinuation Rates During Sunny and Non Sunny Periods" width="1132" height="280"></figure><h2 id="conclusion" data-section="conclusion">Conclusion</h2><ul><li>Prophylactic dose reduction during high UV index months does not compromise isotretinoin efficacy.</li><li>Routine suspension or avoidance of oral isotretinoin during sunny seasons is not supported by clinical evidence.</li><li>Administration at modestly reduced dosage during sunny months is safe and therapeutically effective.</li></ul>

Dermatology Update   Issue 1   Jan 2026

<ul><li><a href="#background">Background</a></li><li><a href="#objectives">Objectives</a></li><li><a href="#methods">Methods</a></li><li><a href="#results">Results</a></li><li><a href="#conclusion">Conclusion</a></li></ul>

Real-World Safety of Oral Isotretinoin During Sunny Months

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