A Randomized, Placebo-Controlled Trial of Gamma Linolenic Acid as an Add-on Therapy to Minocycline for the Treatment of Rosacea

BACKGROUND: A recent study suggested a possible role of skin barrier dysfunction in the pathogenesis of rosacea, which leads to irritation symptoms. Gamma linolenic acid (GLA) is an essential omega-6 fatty acid that is known to restore defective epidermal skin barrier. GLA supplementation has not previously been performed in rosacea patients. OBJECTIVE: To investigate the efficacy and safety of adding GLA to minocycline compared to minocycline alone in rosacea patients. METHODS: This prospective, double-blind, randomized, placebo-controlled trial enrolled 31 rosacea patients. They were randomly assigned to receive 320 mg/day of GLA (Evoprim®) (n=16) or placebo (n=15) in addition to 100 mg/day of minocycline for 8 weeks. Investigator's global assessment (IGA) and patient's global assessment (PGA) were used to assess clinical severity at weeks 0, 4, 8, and 12. Biophysical parameters including melanin index, erythema index, transepidermal water loss (TEWL), lipid concentration, and stratum corneum hydration were measured. RESULTS: In the GLA group, a higher proportion of patients achieved treatment success (IGA≤1) at week 8 (68.75% vs. 33.33%) and patient satisfaction (PGA≥3) at weeks 8 (75.0% vs. 40.0%) and 12 (81.3% vs. 46.6%). Both groups, throughout 12 weeks of treatment, revealed a trend toward improvement in erythema index, melanin index, TEWL, and stratum corneum hydration. Particularly, there was a significant difference in TEWL and stratum corneum hydration over time between the two groups (p=0.033, p=0.003, respectively). No serious adverse event was observed in both groups. CONCLUSION: GLA is beneficial as an additional therapeutic option for rosacea patients treated with minocycline.