Cited skincare — every flag names its source, no upsell.
Re

Resorcinol

Resorcinol · Hexylresorcinol · ButylresorcinolActive

Phenolic tyrosinase-inhibitor used in OTC and Rx brightening products. Less potent than hydroquinone, no rebound concern.

What it does

Resorcinol and its derivatives (hexylresorcinol, 4-butylresorcinol, thiamidol) inhibit tyrosinase to slow melanin production. Used at low concentrations in OTC brighteners and at higher concentrations in dermatology compounding. Reported timelines run longer than hydroquinone's — commonly 8–12 weeks — and these derivatives aren't usually cycled the way hydroquinone is. Generally well-tolerated; mild irritation possible in some users.

The evidence, graded

strongResorcinol derivatives are potent inhibitors of human tyrosinase. Screening against the human enzyme rather than the mushroom enzyme found thiamidol at an IC50 of 1.1 micromolar, against hydroquinone and arbutin in the millimolar range, and a vehicle-controlled trial has since shown benefit on facial hyperpigmentation.Mann 2018 · The Journal of investigative dermatology ↗

Graded per the methodology: strong · moderate · emerging · expert consensus. A weak source on a strong claim gets the weaker label.

Also known as

hexylresorcinol, 4-butylresorcinol, thiamidol

Pairs worth knowing

Niacinamide (Vitamin B3) · works together ↗Alpha Arbutin · works together ↗Tranexamic Acid · works together ↗

Browse all 668 ingredients — grouped by what they do, each with whatever evidence we can cite.

This page is public so a shared ingredient card always has its sources behind it — and so you can check them without an account.
Want more like this?
Every evidence-based flag cites its source, Drop tells you when your routine is complete, and it helps you simplify — instead of selling you more. The app launches on iOS and Android in October 2026. Rate my routine works today at /rate — no sign-in.
See what Drop doesHow Drop works