Keto completely cleared my adult acne — anyone else?

This is well-documented and the mechanism is understood. Acne has strong links to insulin and IGF-1 (insulin-like growth factor). Here's the chain:

High carbohydrate intake → blood sugar spikes → insulin spikes → elevated IGF-1 → increased sebum (oil) production → increased keratinocyte proliferation (skin cell turnover) → clogged pores → acne.

Keto breaks this chain at the insulin step. When insulin stays chronically low, IGF-1 drops, sebum production decreases, skin cell turnover normalizes. Many people see dramatic acne improvement, especially adult acne that hasn't responded to topical treatments (which target the symptom, not the cause).

This is also why high-glycemic-index foods have been linked to acne in multiple studies — bread, sugar, milk, white rice — they all cause insulin spikes. Keto eliminates all of them.

Same experience. Adult cystic acne for 12 years. Dermatologist visits, prescription retinoids, antibiotics, everything. Keto cleared it in about 8 weeks. My dermatologist was actually interested when I told her — she said she'd been seeing this in several patients and was starting to recommend low-glycemic diets for acne patients.

The dairy question: some people find that eliminating dairy as well (full elimination keto — no cheese or cream) clears residual acne that keto alone didn't fully address. Dairy has its own IGF-1 stimulating properties independent of carbohydrate content. Worth trying for a month if you still have some breakouts.

My experience too — not acne exactly but skin was dull, had some rough patches. On keto it became notably clearer and more evenly-toned over about 2 months. I put it down to less inflammation systemically, which shows up in skin. The anti-inflammatory effect of keto seems to extend to skin outcomes beyond just acne.

The frustrating thing is that dermatology as a field has been slow to incorporate diet because "diet doesn't affect acne" was dogma for decades (based on flawed early studies). This is slowly changing, but most people still get prescribed topicals and antibiotics before anyone mentions that eliminating sugar and refined carbs might help.

Congratulations on your clear skin — and on 22 lbs! Sometimes the side effects of keto are more meaningful than the primary goal.

I genuinely cried the first morning I looked in the mirror and my skin was clear. 15 years of dealing with this and the answer was apparently to stop eating bread and sugar. I'm not even angry about the years of antibiotics and topicals — I'm just grateful to have finally found something that works. Thank you for the science explanation, it completely makes sense.

Adding: for anyone reading this with acne who hasn't tried dietary changes, this is one of the most commonly reported non-weight benefits of keto. Give it 8-12 weeks of strict compliance and see what happens to your skin. Many people who started keto for weight loss found the skin clearing was the result they cared about most.