One of the underlying cause of PCOS is elevated levels of male hormones or androgens. While a female body also produces androgens, their levels are usually very low.
However, in PCOS, there is an overproduction of androgens. This causes a lot of the PCOS symptoms like excessive hair growth, called hirsutism (especially on the face, arms, legs, chest, and back), thinning of hair (male pattern hair loss from the head) and acne.
Acne in PCOS is usually prominent on the jawline and is of the painful kind. It is also emotionally disturbing. Anything that reduces the levels of androgens helps immensely in resolving many of these symptoms, including acne. You can read more about natural treatments for PCOS acne in this article.