Conditions · Skin A–Z · Ingredients

Hydroquinone (prescription)

Medically reviewed by Dr Sin Yong · Last reviewed · 9 min read · Assessed personally by Dr Sin Yong · Jump to questions

A prescription depigmenting medicine that strongly inhibits melanin production, used under medical supervision for melasma and hyperpigmentation.

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Hydroquinone is a prescription depigmenting cream that reduces melanin production by inhibiting tyrosinase. In Singapore it is not permitted in cosmetic products and is supplied through a doctor. It is used for melasma, sun spots and post-inflammatory marks in supervised courses with breaks, because prolonged unsupervised use can cause exogenous ochronosis, a blue-grey darkening.

Key Facts

What it is
A prescription depigmenting medicine that strongly inhibits melanin production, used under medical supervision for melasma and hyperpigmentation.
Also called
1,4-dihydroxybenzene; HQ
Pairs with
Strict sunscreen, gentle moisturiser; combinations with retinoids or corticosteroids only as prescribed
Who should take care
It should not be used without medical supervision, during pregnancy or breastfeeding unless a doctor advises, or on broken or inflamed skin.
In Singapore
Hydroquinone is not permitted in cosmetic products in Singapore and is controlled as a prescription medicine supplied through a doctor.

What is hydroquinone and what does it do?

Hydroquinone inhibits tyrosinase, the enzyme that drives melanin production, and is also toxic to overactive melanocytes, reducing pigment production more strongly than most cosmetic brighteners. It is used medically for melasma, post-inflammatory hyperpigmentation and sun spots, sometimes in triple-combination creams with a retinoid and a mild corticosteroid. Because of its strength, it is normally used for defined periods with breaks, rather than continuously, and under review by a doctor. It lightens excess pigment over weeks to months but does not prevent recurrence, so sun protection and maintenance with gentler actives follow. This entry is educational; strength and duration are decided by a doctor. [1]

A woman by a window, hand resting against her cheek, skin evenly lit

“It lightens excess pigment over weeks to months but does not prevent recurrence, so sun protection and maintenance with gentler actives follow.”

Dr Sin YongOn what hydroquinone can and cannot do

What does the evidence show?

Hydroquinone has decades of clinical use and many trials in melasma and hyperpigmentation, and it serves as the comparator against which many newer agents are tested. Reviews support its efficacy while highlighting safety concerns with prolonged or unsupervised use. A systematic review of exogenous ochronosis links this blue-black discolouration mainly to long-term use, including of products bought without supervision, which is why medical review matters.

Who should avoid hydroquinone?

It should not be used without medical supervision, during pregnancy or breastfeeding unless a doctor advises, or on broken or inflamed skin. Prolonged use can cause exogenous ochronosis, a blue-grey darkening that is difficult to reverse, and irritation can trigger rebound pigmentation in darker skin. People with sensitive skin may develop contact dermatitis.

Is hydroquinone available in Singapore?

Hydroquinone is not permitted in cosmetic products in Singapore and is controlled as a prescription medicine supplied through a doctor. The Health Sciences Authority has repeatedly warned about unregistered lightening creams, often sold online, found to contain hydroquinone or mercury. Use only products obtained through a doctor or legitimate pharmacy.

If a dark patch, breakout or irritation is not responding to what you are using, the next step is a diagnosis rather than another product. See the Skin A–Z library for related ingredients.

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Questions Patients Actually Ask

What is Hydroquinone used for?+

A prescription depigmenting medicine that strongly inhibits melanin production, used under medical supervision for melasma and hyperpigmentation.

Who should avoid Hydroquinone?+

It should not be used without medical supervision, during pregnancy or breastfeeding unless a doctor advises, or on broken or inflamed skin. Prolonged use can cause exogenous ochronosis, a blue-grey darkening that is difficult to reverse, and irritation can trigger rebound pigmentation in darker skin. People with sensitive skin may develop contact dermatitis.

Can Hydroquinone be combined with other skincare?+

It is commonly paired with Strict sunscreen, gentle moisturiser; combinations with retinoids or corticosteroids only as prescribed; introduce one new active at a time and stop if irritation develops.

Is hydroquinone legal in Singapore?+
Yes, as a prescription medicine. Hydroquinone is not permitted in cosmetic products in Singapore, so a cream sold over the counter, online or in a salon as a lightening product should not contain it. It is supplied through a doctor after the pigment has been assessed, and the Health Sciences Authority has warned about unregistered creams found to contain hydroquinone or mercury.
What happens when you stop using hydroquinone?+
Pigment that has lightened does not usually darken straight away, but the tendency behind melasma and sun-driven pigment remains, so marks can return with sun exposure, heat or hormonal change. That is why stopping is planned: maintenance with gentler agents such as azelaic acid, a retinoid or tranexamic acid, and daily broad-spectrum sunscreen, continue after the course ends.
Is hydroquinone suitable for Asian or darker skin?+
It can be used in Asian and darker skin under supervision, but two risks are weighed more carefully. Irritation can trigger post-inflammatory hyperpigmentation, and exogenous ochronosis is reported more often in darker skin with prolonged use. Courses are kept time-limited, strength is chosen conservatively, and the skin is reviewed rather than left on the cream indefinitely.

References

  1. Topical Hydroquinone for Hyperpigmentation: A Narrative Review — Cureus, 2023.
  2. Exogenous ochronosis associated with hydroquinone: a systematic review — International Journal of Dermatology, 2022.
  3. Hydroquinone (bleaching cream) — DermNet.

Medically reviewed by Dr Sin Yong, MBBS (NUS), MRCS (Edinburgh) · Last updated 7 September 2026 · Editorial policy

How long can you use hydroquinone cream?

Hydroquinone is used in courses rather than indefinitely, with the length set and reviewed by the prescribing doctor. A course commonly runs for a few months, after which the skin is reassessed. If the pigment has improved, hydroquinone is tapered or paused and maintenance continues with gentler agents and strict sun protection; if nothing has changed, the diagnosis and the plan are revisited rather than the cream simply continued.

The reason for the limit is safety. The risk of exogenous ochronosis rises with long-term, continuous use and with higher strengths, and much of the published harm comes from products used for years without supervision. Irritation is the other limit: an inflamed patch of skin can respond with more pigment, which matters particularly in darker skin.

Courses may be repeated after a break when a doctor considers it appropriate, sometimes in a combination cream with a retinoid and a mild corticosteroid. Strength and timing are decided individually, and this page does not give dosing advice.

What is hydroquinone ochronosis, and can it be reversed?

Exogenous ochronosis is a blue-black or grey-brown darkening of the skin caused by long-term hydroquinone use, in which pigment-like deposits form in the dermis. It typically appears where the cream was applied, such as the cheeks, temples and jaw, and can look like worsening melasma, which sometimes leads people to apply more cream.

It is reported more often in darker skin types, with prolonged use and with high-strength or unregulated products, although it can also follow lower strengths used for long periods. Dermoscopy can raise the suspicion, and a skin biopsy confirms it.

The first step is stopping hydroquinone. Ochronosis is difficult to treat: improvement, where it occurs, is slow and partial, and approaches such as certain lasers have been reported with mixed results. Prevention through supervised, time-limited courses is far more reliable than treatment, which is why the cream is prescribed with a plan for when it stops.

Hydroquinone and the alternatives for hyperpigmentation
OptionWhat it doesWhat it cannot doTypical recoveryWho it tends to suit
Hydroquinone cream (prescription)Inhibits tyrosinase and reduces melanin production in overactive melanocytesPrevent recurrence, or be used continuously without reviewRedness or irritation at first in some people; ochronosis risk with prolonged useMelasma, sun spots and post-inflammatory marks, in supervised courses
Azelaic acidModerates melanin production and calms inflammationClear deep dermal pigment or replace sun protectionMild stinging or itch in the first weeksSensitive or acne-prone skin, maintenance between hydroquinone courses, and pregnancy where a doctor advises
Topical retinoidsSpeed up skin cell turnover so pigment is shed sooner, and help other actives workAct quickly on their own; prescription-strength forms are avoided in pregnancyDryness, peeling and irritation in the first weeksCombination regimens, sun-damaged skin and maintenance
Tranexamic acid (topical or oral)Interferes with the signalling that stimulates melanocytes, particularly in melasmaRemove established sun spots; the oral form is a prescription medicine that needs screening for clotting riskUsually minimal; the oral form is reviewed by a doctor before startingMelasma, alongside sun protection and topical therapy
Laser toning or pico laser (in clinic)Breaks up pigment with controlled light energy at conservative settingsPrevent melasma recurrence; aggressive settings can worsen pigment in darker skinMild redness for a short period; varies with settingsPigment that has plateaued on topicals, once the pigment type is diagnosed
Daily broad-spectrum sunscreenReduces the ultraviolet and visible-light stimulus that drives pigmentLighten existing pigment on its ownNoneEveryone using any lightening treatment; tinted formulas help in melasma

Availability in Singapore

Hydroquinone is prohibited in cosmetic products in Singapore under Annex II of the ASEAN Cosmetic Directive, and the HSA states it is a potent ingredient used only in prescription medicines under medical supervision. Creams containing it, in any strength, are therefore prescription-only and obtained through a doctor; HSA alerts regularly list imported 'whitening' creams found to contain undeclared hydroquinone. A doctor assesses whether the pigmentation is melasma, post-inflammatory marks or sun damage, then prescribes a strength and duration with review, because prolonged unsupervised use risks ochronosis. Source.

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