12
Acne.org. Hormones and Acne – Testosterone and Estrogen.
13
V Goulden et al., J Am Acad Dermatol. Prevalence of facial acne in adults. 1999 Oct;41(4):577–80.
14
Acne.org. Accutane (Isotretinoin). Everything You Need to Know About Isotretinoin.