In a 10-week, randomized, controlled trial, 45 participants with mild to moderate acne, participants were given either Omega-3 fatty acids (2,000 mg EPA/DHA), borage oil (400 mg LA), or placebo. In the supplemented groups, both non-inflammatory and inflammatory lesions decreased along self-assessment of disease severity.

Jung JY, Kwon HH, Hong JS, Yoon JY, Park MS, Jang MY, Suh DH. Effect of dietary supplementation with omega-3 fatty acid and gamma-linolenic acid on acne vulgaris: a randomised, double-blind, controlled trial. Acta Derm Venereol. 2014 Sep;94(5):521-5. PMID: 24553997.