Hydroquinone, Pigmentation and the Obagi Nu-Derm Cycle

If a client comes to me with melasma, sun damage or post-inflammatory hyperpigmentation that has not responded to two or three rounds of brighteners and a decent retinol, the conversation that follows is almost always about hydroquinone.

Hydroquinone is the most effective topical pigmentation treatment available. It is also the most misunderstood. There are persistent myths in beauty media — that it's banned, that it's dangerous, that it bleaches the skin permanently — and they are mostly wrong. The reality is more interesting and more useful, and worth explaining clearly.

What hydroquinone actually does

Pigmentation is produced by melanocytes — specialised cells in the skin that synthesise melanin in response to UV exposure, hormonal triggers, inflammation and genetics. Hydroquinone works by inhibiting tyrosinase, the enzyme melanocytes use to produce melanin. With production suppressed, the existing pigment cycles out of the skin via natural turnover, and new pigment doesn't replace it. Over twelve to twenty-four weeks, that produces a measurable, visible reduction in pigmented patches.

The strongest available formulations contain 4% hydroquinone. At that concentration, in the UK, hydroquinone is a prescription-only medicine — issued by a doctor or other registered prescriber, dispensed by a pharmacy, used under clinical oversight.

Is hydroquinone banned?

In the UK, hydroquinone is not banned. It is restricted. You cannot buy it over the counter. You cannot legally have it dispensed without a prescription. Some online suppliers — usually based outside the UK — sell hydroquinone-containing products to the UK market. Those products are unlicensed, often higher-concentration than is safe to use unsupervised, and not infrequently contaminated with mercury, steroids or other illegal additives.

In the US, hydroquinone at 2% is available over the counter and at 4% via prescription. In some Asian markets, it is available without restriction. In the EU, the position is similar to the UK — prescription-only or restricted to specific cosmetic concentrations.

The UK position is the right one, in my view. Hydroquinone used appropriately is excellent. Hydroquinone used unsupervised — wrong concentration, wrong duration, no supporting routine, no SPF — produces a complication called exogenous ochronosis, a paradoxical darkening that can be permanent. The supervision is what makes the result safe.

The Obagi Nu-Derm system

The most evidence-supported way to use hydroquinone is inside a structured system. The protocol I use most often in clinic is the Obagi Medical Nu-Derm system — a sequenced six-step routine that includes 4% hydroquinone alongside tretinoin, exfoliating actives, and a calibrated barrier-repair phase.

The system runs in cycles. A typical cycle is twelve to twenty-four weeks of active use, followed by a defined break of similar length on a maintenance routine that supports the result without prolonged hydroquinone exposure. Most clients run two to three cycles across an eighteen-month plan, depending on the depth and stubbornness of the pigmentation. We do not use hydroquinone indefinitely.

Inside the cycle, the sequencing matters. The hydroquinone-containing steps work better when paired with the system's tretinoin and exfoliators. Used alone, hydroquinone produces about half the result.

What needs to be true before I prescribe it

The non-negotiables in clinic before I issue a prescription:

A documented baseline. Photographs at the start of the cycle, at six weeks, twelve weeks, and end of cycle. Without that, neither of us can see the rate of change or decide when to step the routine down.

A pregnancy and breastfeeding screen — hydroquinone is contraindicated in both. A medication and skin-condition history — there are a small number of conditions and active treatments that change what we use.

An SPF commitment. Hydroquinone without daily, structured SPF is the most reliable way to undo the work as fast as it happens. UV exposure during a cycle is the single biggest reason a result plateaus or rebounds.

A clear plan for the post-cycle phase. Some clients move onto a tretinoin-only maintenance phase. Some move onto a vitamin C and tranexamic acid phase. Some need a regenerative treatment alongside — polynucleotides have a meaningful role for stubborn melasma and are increasingly part of the protocol.

Where this conversation belongs

Pigmentation is one of the most rewarding concerns to treat well, and one of the most common ones to treat badly. The wrong product on the wrong skin tone, used for too long without oversight, makes pigmentation worse permanently. The right product on the right skin, inside a structured cycle with proper review, transforms it.

If you have stubborn melasma, sun damage or post-inflammatory pigmentation that has not responded to over-the-counter brighteners, the next step is a Reveal Consultation. We assess the depth and pattern of the pigmentation, take a baseline, and decide together whether prescription hydroquinone is the right tool — and if it is, build the cycle around it.