Antioxidant

P-Hydroxyanisole

INCI: P-HYDROXYANISOLE

Reviewed by Rosie · Last updated 14 Aug 2026

An antioxidant with potential depigmenting properties, studied primarily for specialised applications

Best For Skin Types

All

Addresses

Hyperpigmentation, Photoaging

Usage Frequency

Daily

What Is P-Hydroxyanisole?

P-hydroxyanisole is a synthetic aromatic compound belonging to the phenolic antioxidant family. It functions primarily as an antioxidant in skincare formulations, helping to neutralise free radicals and protect against oxidative stress.

The ingredient has been investigated in dermatological research for depigmenting applications, particularly in the management of conditions affecting skin colour. Its mechanism centres on reducing melanin production through tyrosinase inhibition, though it remains a less commonly used option compared to established alternatives like hydroquinone or azelaic acid.

Benefits for Your Skin

How It Works

As an antioxidant, p-hydroxyanisole neutralises free radicals by donating electrons, thereby preventing oxidative chain reactions that can damage skin cells. This protective mechanism is particularly relevant in the context of photoaging and cumulative UV damage.

When used for depigmentation, the ingredient is thought to inhibit tyrosinase, the enzyme responsible for melanin synthesis. However, the precise clinical mechanisms and comparative efficacy relative to more established depigmenting agents remain incompletely characterised in published literature.

Clinical Evidence & References

P-hydroxyanisole appears in dermatological literature primarily as a depigmenting agent, though the volume of clinical trial data is modest. Research on solar lentigines and postinflammatory hyperpigmentation indicates that topical tyrosinase inhibitors—a category including p-hydroxyanisole—can contribute to lightening effects when combined with photoprotection, though results vary by individual and skin type.

Evidence for this ingredient specifically is less extensive than for alternatives such as hydroquinone, azelaic acid, or kojic acid. Its antioxidant properties are supported by basic chemistry, but dedicated clinical efficacy trials comparing it directly to established options would strengthen the evidence base. Any use should be accompanied by consistent sun protection, as UV exposure will undermine depigmenting efforts.

How to Use

If used as part of a depigmentation regimen, apply to clean, dry skin and use consistently as directed. Because depigmenting treatments work gradually—often requiring weeks to months—patience and adherence are essential. Always combine with a broad-spectrum SPF 30 or higher during the day, as sun exposure will compromise results and may trigger further pigmentation. Consider introducing the ingredient gradually and monitor for any signs of irritation. Consultation with a dermatologist is advisable before starting, particularly if you have darker skin tones or a history of postinflammatory hyperpigmentation, as these require careful management.

Safety & Precautions

P-hydroxyanisole is generally recognised as well-tolerated in topical applications at typical concentrations. As with any tyrosinase inhibitor, there is theoretical risk of irritation or contact sensitisation in susceptible individuals; patch testing is sensible before full application.

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