Ingredient

Hydroquinone

The strongest cream we have for melasma and stubborn dark marks. It is used in courses of a few months rather than continuously, and it needs a prescription in the United States.
Dr. Schwarz, MD · Board-certified dermatologistLast reviewed September 8, 2026
Hydroquinone

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Hydroquinone is still the most effective cream we have for melasma and stubborn dark marks. The argument is about the rest — how strong, for how long, and what happens when the course ends. I use it in courses, three to four months on and then a break, because open-ended use is what causes exogenous ochronosis, a stubborn gray-blue darkening harder to treat than the pigment we started with. And I ask where the cream came from, because imported whitening creams have been found to contain undeclared hydroquinone, steroids and mercury.

— Dr. Schwarz, Board Certified Dermatologist

Key Facts

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Also calledHQ, hydroquinone, quinol; part of Tri-Luma and of compounded creams
TypePigment-blocking cream (tyrosinase inhibitor)
Strengths sold2% and 4% are the usual prescription strengths; compounded creams can be higher
UseOnce a day at night, on the dark patches only
Time to work4 to 8 weeks for early change, about 3 months to judge
Course lengthA few months, then a break
Prescription neededYes in the United States. Rules differ by country.

What It Is

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Hydroquinone is a small molecule that blocks the skin's pigment-making machinery. It has been used on skin for more than fifty years, and most of the melasma evidence is built on it. Its legal status in the United States changed in 2020. For decades, 2% was sold over the counter under an old rule that let some older medicines stay on the shelf while their safety review was finished. A law passed in 2020 closed that route before the review was done, so it is now prescription-only, and the FDA has warned companies that kept selling it. Elsewhere the rules differ. The European Union prohibits it in cosmetics altogether; some countries still sell it over the counter. That is why the same tube can be legal in one place, prescription-only in another and banned in a third, and why creams bought abroad are hard to judge.

How It Works

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Pigment cells called melanocytes make melanin using an enzyme called tyrosinase. Hydroquinone looks enough like that enzyme's normal target to get in its way, so less melanin is made. At higher strengths it also damages the compartments where melanin is packaged, and can be toxic to the cell itself.

It does not remove pigment already there. It stops new pigment being made while normal turnover carries the old pigment up and off the surface. That is why nothing happens in the first few weeks, and why sun undoes the work — ultraviolet light tells pigment cells to make more, faster than the cream can hold them back.

It is used in courses because of a side effect called exogenous ochronosis. After long uninterrupted use, treated skin can turn gray-blue or slate-brown, sometimes with tiny dark specks or a rough, caviar-like surface. The cream meant to lighten the patch has darkened it, and it is often harder to treat than the original pigment. It turns up mostly after years of high-strength use, and more often in deeper skin tones. At the strengths and course lengths used in dermatology it is uncommon, and breaks keep the risk small.

Hydroquinone does nothing about why the pigment appeared. Melasma is driven by sun, heat and hormones; marks from acne or eczema by the inflammation that came first. If that does not change, the patches return once the course ends.

Here is where Hydroquinone acts in the skin.

About Hydroquinone
Skin basics
SLOWS PIGMENT MAKINGCROSSES EASILY

Pigment is made inside melanocytes, cells spaced along the floor of the top layer of skin. Hydroquinone slows the enzyme they use to make it, so less new pigment reaches the surface while what is already there sheds. The strongest and most studied. Used in courses with breaks, not forever.

Hydroquinone is small and crosses the barrier readily. That is why it works where gentler brighteners stall, and why it is the one that needs a doctor watching how long you use it.

The outermost layer, and the one every moisturizer is aiming at. It is dead — flattened cells stacked like bricks, with a mix of fats as the glue between them. That glue is what holds water in and keeps irritants out.

The outer layer, and the only one anything in a jar reaches. It renews itself constantly: a cell made at the bottom takes about a month to reach the surface and flake off. Most of what a skincare product does, it does here.

The living layer underneath, holding the blood vessels, the nerves and the collagen. It is where lasting change happens and it is hard to reach: most of what is sold for the skin never gets this far.

What It Treats

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No strong evidence for any condition.

Forms

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Hydroquinone comes as a cream, less often a gel, lotion or solution, and in the United States all of it needs a prescription. The most common version pairs it with a retinoid and a mild steroid — a triple cream, and the steroid is why it is not for open-ended use. It oxidizes in air and light, so tubes are opaque and a cream that has browned has degraded. Imported skin-lightening creams with no readable ingredient list have been found to contain steroids and mercury.

A row of Hydroquinone products sold as cream, 4%, photographed on white.
The standard prescription
Cream, 4%
The most common form. Applied to the marks only, not the whole face.
A row of Hydroquinone products sold as triple combination cream, photographed on white.
With a retinoid and a steroid
Triple combination cream
Works faster and cannot be used indefinitely, because of the steroid.
A row of Hydroquinone products sold as gel or solution, photographed on white.
Oily skin
Gel or solution
A lighter base for the same drug. Less widely prescribed.
6% to 10%
Compounded strengths
Made up by a pharmacy on a prescriber's instruction. Stronger, and more irritating.
Do not use
Unlabeled imported creams
No strength, no ingredient list, no manufacturer. Found to contain steroids and mercury.

Strengths

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Strength matters, course length matters more. A higher percentage for a few months is a different proposition from a low one for years, and the second causes the trouble.

WeakestStrongest
2%4%Above 4%
The lower prescription strength
2%
What used to be sold over the counter in the United States. A reasonable start, and often enough for marks left by acne.
The usual prescription strength
4%
What most of the melasma evidence used. More effective than 2%, and more irritating.
Compounded only
Above 4%
Made up by a compounding pharmacy for specific cases. Harsher, and the range where exogenous ochronosis has most often been reported. Not a strength to seek out on your own.

Basics

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When to Apply
At night, after cleansing, before moisturizer. A thin layer on the dark patches only, not the whole face. Sunscreen every morning is part of the treatment — without it the cream is working against the sun and losing.
How to Start
Once a day is standard; many plans start every other night for the first week. Use a fingertip and stay on the patch — spreading it onto normal skin lightens that too and leaves a visible halo.
If It Irritates
Mild stinging, redness and dryness in the first two weeks are common. Moisturizer first and the cream on top, or drop to every other night. Irritation is not harmless here — inflammation in skin that pigments easily leaves new marks, the opposite of the point.
If It’s Not Working
Give it three months of nightly use with daily sunscreen. If nothing has moved, the next steps are a higher strength, a retinoid added, or treating the trigger rather than the patch. If a patch is getting darker, grayer or bluer, stop and have it looked at.

Sample Routine

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Here is where Hydroquinone sits in a day, and what goes around it. Pick what you are treating and what your skin is like, and the rest of the routine changes to suit.

What to Expect

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Weeks 1 to 2Weeks 4 to 8Months 3 to 4After the course
Adjusting
Weeks 1 to 2
Stinging, mild redness and dryness on the treated patches. No lightening yet.
Working
Weeks 4 to 8
The patches begin to lighten, usually at the edges. Newer marks move faster than old ones.
Judge it here
Months 3 to 4
Where you decide whether it worked, and where most courses end.
Take a break
After the course
A few months off, holding the result with sunscreen and something gentler.

What to Avoid

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  • Sun without sunscreen Not general advice here. A single unprotected day can undo weeks of work, and it is the commonest reason a course fails.
  • Peroxides in the same layer Benzoyl peroxide or hydrogen peroxide alongside hydroquinone can temporarily stain the skin dark brown. It washes out, but it is alarming. Separate them by time of day.
  • Using it continuously for years The most important rule on this page. Courses of a few months with breaks, not an open-ended nightly habit.
  • Spreading it over the whole face It lightens untreated skin too, leaving an obvious edge where the treated area stops.
  • Imported creams with no ingredient list These have been found to contain undeclared steroids, unstated hydroquinone strengths and mercury.
  • Waxing, strong peels and scrubs On treated skin. It irritates more easily, and that inflammation can leave new marks.
  • The folklore hydroquinone is often called bleach. It is not. It does not strip color out of skin; it slows new pigment while what is already there fades on its own schedule. That is why it takes months and why it wears off.

If You Stop

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Patches that lightened do not darken again overnight. What returns is the reason they were there. Melasma is likeliest, often within a few months if sun, heat and hormonal drivers are unchanged. Marks from acne or eczema rarely return unless new spots keep forming. So hydroquinone is usually the start of a plan, not the whole of it. Most people finish a course and hold the result with daily sunscreen and something gentler — azelaic acid, cysteamine, tranexamic acid, niacinamide or a retinoid — returning to hydroquinone only if the pigment creeps back. Stopping does not cause a rebound worse than baseline. Pigment resumes at whatever pace its trigger sets.

Ask Your Doctor

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If you are pregnant or breastfeeding
More is absorbed through the skin than with most creams. Ask the doctor managing your pregnancy before using it.
If you have used it without a break
For more than four to six months. Uninterrupted use is what raises the risk of exogenous ochronosis.
If a treated patch is getting darker
Gray or blue rather than lighter. Stop and have it looked at.
If you see tiny dark specks
Or a rough, caviar-like surface on treated skin. This is how ochronosis often first shows.
If stinging or redness has not settled
After a month it should have eased.
If you have a sulfite allergy
Some products contain sodium metabisulfite, which can cause severe reactions in people sensitive to it.
If you are using an imported cream
And do not know its strength or ingredients. What is in it matters more than how you use it.

How It Compares

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Five azelaic acid tubes and bottles on white, most marked 10 percent, from Peach Slices, Paula's Choice, Facetheory, The Ordinary and NaturiumLabeled cutaway diagram of a single skin pore, headed Azelaic Acid. The epidermis is a brick-textured band across the top and the dermis is pink below it, with a yellow oil gland at the base of the pore and a small cluster of bacteria inside it. Three callout lines point in: decreases dead cells in pore and kills bacteria are drawn in dark navy as main effects, and decreases inflammation is drawn in gray as a lesser one.

Azelaic acid

Worse

Slower and much gentler, usable continuously, and the usual choice during pregnancy. Hydroquinone is more effective on stubborn melasma.

Four cysteamine products: a Senté tube, an Omic+ cream and box, a 5% cysteamine serum dropper and a Cyspera bottle16:9 hero for Cysteamine. Never cropped: the tone strip and the corner logo depend on the full frame.

Cysteamine

The same

Including trials run against hydroquinone directly. Can be used for longer stretches and has not been linked to ochronosis, but it smells strongly of sulfur.

Five serums lined up on white, labeled tranexamic acid or niacinamide with TXA, including SkinCeuticals Discoloration Defense16:9 hero for Tranexamic Acid. Never cropped: the tone strip and the corner logo depend on the full frame.

Tranexamic acid

Different job

Stronger for the oral form than the cream. Often used to hold melasma between hydroquinone courses. Oral use needs medical supervision because of clotting risk.

Topical retinoids

Different job

Slower on pigment, and usually combined with hydroquinone rather than compared against it. Not used in pregnancy.

Six niacinamide products on white, including The Ordinary 10% + Zinc 1%, Paula's Choice Booster and EltaMD UV ClearLabeled cutaway diagram of a single skin pore, headed Niacinamide. The epidermis is a brick-textured band across the top and the dermis is pink below it, with a yellow oil gland at the base of the pore and a small cluster of bacteria inside it. Two callout lines point in: decreases inflammation is drawn in dark navy as the main effect, and decreases oil production is drawn in gray as a lesser one. Nothing points at the dead cells blocking the pore.

Niacinamide

Worse

Very well tolerated and easy to add to anything, but far weaker on established patches.

Five licorice root products on white, including two Acwell bottles, Éminence, Horbäach liquid extract and Versed16:9 hero for Licorice Root Extract. Never cropped: the tone strip and the corner logo depend on the full frame.

Licorice root extract

Worse

Gentle and cosmetic, reasonable as maintenance, and nowhere near hydroquinone on active melasma.

Chemical peels and lasers

The same

Heavily dependent on who is doing them. They can shift pigment faster, and done badly they can make melasma worse, particularly in deeper skin tones.

Myths

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  • “Hydroquinone causes cancer.” The concern comes from rodents given large oral doses, not from people using a cream. Decades of use have not shown consistent evidence of cancer in people. It lost over-the-counter status in the United States because a safety review was never finished, not because a risk was found.
  • “It bleaches the skin permanently.” It does neither. It slows new pigment, and normal color returns after the cream stops.
  • “It is banned because it is dangerous.” Its status differs by country prescription-only in the United States, prohibited in cosmetics in the European Union, over the counter elsewhere. That reflects different regulatory systems, not one verdict.
  • “It thins the skin.” Hydroquinone does not The steroid in a triple cream can, which is why a triple cream is not for indefinite use.
  • “It is not safe for deeper skin tones.” It is used in every skin tone, and much of the melasma evidence comes from deeper skin tones. Strength and duration need care — ochronosis is reported more often in deeper skin tones, and irritation itself leaves marks.
  • “If some works, more works faster.” Higher strengths irritate more, and irritation in pigment-prone skin creates new marks.

Questions Patients Ask

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Why do I need a prescription for hydroquinone now?

In the United States, 2% was sold over the counter under an old rule that let some older medicines stay on the shelf while their safety review was finished. A law passed in 2020 closed that route before the review was done. Anything sold without a prescription now is not authorized, whatever the packaging says.

How long can I use it?

A course of about three to four months, then a similar break. Continuous use over years raises the risk of exogenous ochronosis and stops adding benefit. Longer courses happen under supervision, as a decision rather than a default.

What is exogenous ochronosis, and would I notice it?

A gray-blue or slate-brown darkening of skin treated for a long time, sometimes with tiny dark specks or a rough surface. It looks like the melasma getting worse, so people use more cream. If a treated patch is darkening rather than lightening, stop and have it checked.

Is hydroquinone safe for deeper skin tones?

Yes — much of the melasma evidence comes from deeper skin tones. Two things need care. Ochronosis is reported more often in deeper skin tones, so course length matters. And irritation leaves marks readily, so a strength that stings every night is working against you.

Can I use hydroquinone in pregnancy?

More of it is absorbed through the skin than with most topicals, so it is usually stopped. Azelaic acid is the common substitute. Ask the doctor managing your pregnancy.

Will it lighten my whole face or change my skin color?

That is not what it is for, and used that way it goes wrong. It works on defined patches. Applied all over it produces uneven color and a visible edge — the pattern behind most of the harm linked to this ingredient, especially with unregulated imported creams.

References

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