4-Butylresorcinol

At a glance

CAS number

18979-61-8

INCI name

4-Butylresorcinol

Function

skin brightening, tyrosinase inhibitor, depigmenting agent, antioxidant

Typical use level

0.1%–1%

Solubility

oil

Stable pH

4–7

CAS number and synonyms are sourced from PubChem. Function, usage levels, pH and compatibility are AI-assisted formulation guidance — verify against your supplier's technical data sheet and applicable regulations before use.

Also known as

Butylresorcinol 4-n-Butylresorcinol Rucinol 2,4-Dihydroxybutylbenzene

Compatibility

Works well with:
Niacinamide Alpha Arbutin Kojic Acid Vitamin C (Ascorbic Acid derivatives) Tranexamic Acid Hyaluronic Acid

Use caution with:
High pH formulations Oxidizing agents

4-Butylresorcinol is sensitive to oxidation and can discolor (turn pink or brown) when exposed to air, light, or alkaline conditions; nitrogen blanketing and airtight packaging are strongly recommended. It pairs well with complementary brightening agents such as niacinamide or alpha arbutin for a synergistic melanogenesis-inhibiting effect. Avoid combining with strong oxidizing agents or formulating above pH 7, as stability degrades significantly.

Formulation notes

4-Butylresorcinol is a potent skin-brightening active that inhibits both tyrosinase and peroxidase enzymes involved in melanin synthesis, making it highly effective for addressing hyperpigmentation, dark spots, and uneven skin tone at concentrations as low as 0.1%. It is more lipophilic than kojic acid or standard resorcinol, facilitating better skin penetration. Formulators should handle it under inert atmosphere conditions and use appropriate antioxidant stabilizers (e.g., BHT, sodium metabisulfite) to prevent oxidative discoloration during manufacturing and shelf life.

Frequently asked questions

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