I always break out around my jaw and chin

Sebaceous glands — the oil-producing glands responsible for most acne — are distributed differently across the face. The lower face has a high concentration, and these glands are particularly responsive to androgens.

Androgens stimulate sebum production. When androgen levels are elevated or when the skin has a higher sensitivity to normal androgen levels, the lower face responds first and most visibly. This is why jawline and chin breakouts are sometimes called "hormonal acne" — they're not just correlated with hormonal shifts, they're mechanistically caused by them.

In women, this pattern often flares in the week before menstruation, when oestrogen drops and androgens are proportionally more active. It can also appear during or after stopping hormonal contraception, during perimenopause, and post-natally.

It's not always about high androgens. Sometimes it's about the ratio. When oestrogen is lower than usual — through the luteal phase, during perimenopause, or in the years after stopping the pill — androgens that were previously balanced by higher oestrogen can become more active relative to their baseline.

This means the same absolute androgen level that was unremarkable before can produce more visible skin effects in a lower-oestrogen environment. The breakout pattern shifts without the underlying androgen level necessarily changing significantly.

Topical treatments — benzoyl peroxide, salicylic acid, retinoids — can reduce the active breakout but tend not to prevent the next cycle if the hormonal driver hasn't changed. This is the defining feature of hormonally-driven jaw/chin breakouts: they respond partially to topical treatment, then return predictably.

Dietary changes help some people, particularly reducing high-glycaemic foods that spike insulin (which in turn stimulates androgen production). But for someone with a strongly androgenic skin pattern, dietary adjustments alone tend to reduce severity without eliminating the cycle.