Common Name(s): Polydihydroxyindole,polydihydroxyindole,melanin-like biopolymer,natural pigment uv-absorber skin conditioner

CAS Number: N/a

DESCRIPTION

What It Does: Provides broadband uv photoprotection from the melanin-like extended aromatic polymer absorbing across uva/uvb, antioxidant radical scavenging from the polyindole radical stabilisation, and skin conditioning from the melanin-type biopolymer's sc protein affinity.

Why It's Used: Poly-dhi provides the uv protection chemistry of melanin in an exogenously applicable form — the same aromatic polymer that protects melanocytes from uv-induced oxidative damage applicable as a topical photoprotective and antioxidant ingredient.

How It Works: Dhi oxidation polymerisation: 5,6-dihydroxyindole → semiquinone radical → dhi dimers → extended poly-dhi (eumelanin-type). polymer uv absorption: the extended conjugated aromatic system provides continuous broadband uv absorption across 280-400 nm with no discrete peak (unlike molecular uv filters). antioxidant: catechol/o-quinone redox cycling provides radical donation.

Typically Found In: Uv protection,anti-aging,skin care

TECHNICAL DETAILS

Primary Category: Active ingredient – cosmetic active

Secondary Functions: Skin conditioning

Application Areas:

Typical Concentration Range: 0.01%–2%

SOURCING & ETHICS

Vegan Status: Conditional - supplier confirmation required

Halal Status: Unverified - supplier confirmation required

Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier. [audit 2026-07-29 rev2: the record's own source_notes does not assert a non-animal origin, or instructs the reader to verify with the supplier; "yes" asserts knowledge the record does not hold. determination requires shariah-panel sign-off.]

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Well-tolerated by most skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Good safety profile at recommended concentrations. ewg score: 1–2.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Poly-dhi natural cosmetics: the melanin biopolymer provides authentic natural-origin uv protection for clean beauty formulations — unlike synthetic uv filters, the melanin-mimetic polymer is a naturally occurring biopolymer with gras-adjacent safety from human melanin's structural identity.

Last Verified: 2026-03-22

Primary Sources: Cosing database,polydihydroxyindole melanin biopolymer uv antioxidant review