Hydroquinone

Hydroquinone at Prescription Skin

Hydroquinone is a prescription skin-lightening agent used in dermatology for more than five decades to treat excess or uneven pigmentation. It is considered a gold-standard topical option for melasma, chloasma, sun spots, freckles and post-inflammatory hyperpigmentation. Unlike ordinary brightening products that mainly exfoliate, hydroquinone acts directly on pigment-making cells. Lower strengths up to 2 percent may be available over the counter, but the strengths that deliver the most reliable results commonly 4 percent and combination formulas require medical supervision. At Prescription Skin we often place hydroquinone within a broader pigment program alongside retinoids and, in selected cases, a mild anti-inflammatory to improve penetration, tolerance and outcomes.

How hydroquinone works

Tyrosinase inhibition

Skin colour is determined by melanin made in specialised cells called melanocytes. In areas of hyperpigmentation, these cells are working harder than usual. Hydroquinone turns the dial down by blocking tyrosinase, the key enzyme that converts building blocks like L-tyrosine and L-DOPA into melanin. With tyrosinase suppressed, less new pigment is produced and the treated area gradually lightens. You will not see an overnight change; most people notice a steady fade over weeks as newer skin layers contain less pigment. Daily sunscreen is essential during this process because UV light reactivates tyrosinase and can quickly undo progress. If lightening seems to stall, it is often a sign to review application consistency and sun protection rather than a failure of the ingredient.

Melanosome formation and transfer

Melanin is packed into tiny “pigment parcels” called melanosomes that melanocytes pass to surrounding skin cells. Hydroquinone can reduce how many of these parcels are formed and how efficiently they are handed over. Fewer melanosomes reaching the surface means less visible colour in the patch you are treating. Think of it as slowing both the factory (melanin making) and the delivery vans (melanosome transfer). This two-pronged effect helps improve blotchiness at the surface while also reducing new pigment arriving from below. Consistent use smooths out contrast with the surrounding skin so the edge of a spot looks softer and less defined.

Reaching stubborn pigment

Because hydroquinone acts at the point where pigment is produced, it can reach deeper or more established marks that often ignore scrubs, peels or weaker brighteners. This is why clinicians use it for hard-to-shift issues like melasma and long-standing post-acne marks. For very persistent patches, hydroquinone is often paired with supporting ingredients chosen by your doctor, and sometimes used in time-limited courses with breaks to maintain results. The aim is controlled, even fading rather than over-lightening, so careful application to the darker areas and rigorous daily SPF are part of every plan.

What hydroquinone can help with

Melasma and hormonal pigment

Hydroquinone is a first-line lightening ingredient for many patterns of melasma. It helps quiet the overactive pigment switch inside melanocytes so patches look lighter and the contrast with surrounding skin softens. It works best with daily SPF50, shade and heat minimisation, and is often paired with other doctor-selected actives for steadier gains.

Post-inflammatory hyperpigmentation (PIH)

Dark marks that linger after acne, bites or irritation respond well because hydroquinone targets the same pigment pathway that was switched on by inflammation. With consistent use, spots fade more evenly so makeup matches more easily and marks are less likely to “stick.”

Sun spots and uneven tone

Solar lentigines and general sun-related blotchiness often improve as new excess pigment is made more slowly. You can expect softening of edges first, then an overall evening of tone when sunscreen is used every day to prevent re-darkening.

The 10 rules of hydroquinone

1. 1. Use it only on the dark spotsApply a thin film to the pigmented areas, not the whole face. Think “trace the spot,” not “paint the zone.” Keep 3–5 mm away from nostrils, lips and eyelid margins. Treat the entire individual spot rather than dotting the very darkest center. This helps avoid a halo effect and leads to more even blending with surrounding skin.
   2. Treatment window and breaksUse in defined courses, usually 8–12 weeks at a time. Do not use continuously for many months. After a course, switch to maintenance without hydroquinone for at least the same length of time.
   3. Sun protection is non-negotiableWear SPF50 every morning, reapply with extended outdoor time, add hat and shade. UV and heat can quickly undo progress and trigger rebound darkening.
   4. Do not use on broken or irritated skinAvoid areas with eczema, open pimples, cuts, recent waxing, peels, or laser treatments until they are fully healed. Stop several days before peels, microneedling, laser or intense facials, and wait for clinician clearance before restarting.
   5. Watch for warning signsStop and contact us if you see severe irritation, blistering, crusting, paradoxical darkening, or a slate-blue or gray discoloration. That last pattern can signal ochronosis and needs review.
   6. Avoid mixing with unnecessary irritantsDo not layer with strong leave-on acids on the same night when you are starting. If you also use a retinoid, follow your prescribed plan; many patients alternate nights or use a fixed combination given by the doctor.
   7. A pea is plentyFor the face, a pea-sized amount is usually enough when you are spot-treating. More product does not mean faster results and increases irritation risk.
   8. Area limitsDo not use over very large body areas or as an all-over “bleach.” It is a targeted medicine for excess brown pigment, not a skin-lightening cosmetic.
   9. Combine only under guidanceHydroquinone is often paired with a retinoid and a mild anti-inflammatory in prescription combinations. Follow the exact schedule provided. Do not add exfoliators or new actives without checking first.
   10. Hands and transferWash hands after application. Avoid transferring product to eyelids, corners of the mouth, or inside the nose.

How to apply

Cleanse and dry the skin completely. Apply a thin layer of hydroquinone only to the darker areas at night. Allow it to absorb, then apply moisturiser if needed. Do not layer over areas recently treated with benzoyl peroxide or other peroxide-containing products on the same night due to the risk of temporary dark staining. In the morning, apply broad-spectrum SPF30 plus or SPF50 plus and reapply if outdoors.

Side effects and what is normal

In the first one to two weeks mild tingling, a warm flush, slight dryness and fine flaking are common. These usually settle with a gentle moisturiser and daily sunscreen. If irritation appears as stinging that lasts beyond 10 to 15 minutes, day-long redness or patchy dryness, slow down. Use every second night, apply a thicker moisturiser, and target spots rather than large areas. Allergy is less common but needs attention. Spreading itch, swelling, tiny bumps or a rash beyond the treated area means stop and contact us so we can switch your plan.

To avoid uneven lightening, treat the whole spot rather than only the darkest centre. Wash hands after use and keep a small margin from eyelids, lips and nostrils. Hydroquinone is not a sunscreen, so skipping SPF can trigger rebound darkening.

Rare but important: very long, continuous use at higher strengths can cause gray-blue discoloration called exogenous ochronosis. We reduce this risk with set courses, breaks and strict photoprotection. Tell us promptly if you notice slate-gray or blue-brown patches.

Stop and check in for severe burning, crusting, open cracks, swelling, hives, eye involvement or gray-blue color change. Pause around peels, microneedling or laser until cleared to restart. Avoid during pregnancy, while trying to conceive and during breastfeeding.

When will I see results

• 2–4 weeks: Blotchiness can start to soften. Spots may look a little lighter at the edges and makeup blends more easily. The key changes are subtle because you are slowing new pigment production rather than stripping colour from the surface.
• 6–8 weeks: Individual marks usually look lighter and less defined. Post-acne marks often fade faster than long-standing patches. If you are treating melasma, expect steadier, more gradual change.
• 12–16 weeks: This is the common window for clearly visible improvement. Tone looks more even, contrast between the dark patch and surrounding skin is reduced, and new marks are less likely to set in if sunscreen is consistent.
• Beyond 16 weeks: Some cases, especially melasma or deep dermal pigment, need longer courses and maintenance. Your clinician may cycle treatment, for example several months on followed by a break or a step-down plan, to maintain gains while protecting the skin barrier.

When to avoid or use caution

Hydroquinone should be avoided during pregnancy and breastfeeding. It is not suitable if you have a known allergy to hydroquinone or to other ingredients in the formulation. Use caution with very sensitive or inflamed skin, active eczema on the treatment area, or a history of ochronosis from unsupervised lightening products. Do not apply to broken, freshly shaved or irritated skin, and do not use at the same time as peroxide-based acne products on the same area. People with high UV exposure must be meticulous with SPF, hats and shade.

FAQs

How to get started

Sign up for Prescription Skin, complete your Skin Questionnaire, and have your consultation with your doctor to discuss your skin history and goals. Your doctor will then prescribe a personalised Prescription Skin formula, which will be compounded, packed and shipped directly to you. Subscribers can have their formula reviewed every 2 months at no extra cost.

How long can I use hydroquinone

Typical courses run 3 to 6 months. We reassess at around 3 months and usually cycle off by 6 months, then move to maintenance with non-hydroquinone brighteners.

Can I apply hydroquinone to my whole face

No. Apply only to the darker patches to avoid lightening normal surrounding skin. Your doctor will show you exactly where to apply.

Can I use hydroquinone with a retinoid

Yes, often in an alternating schedule or as part of a combination plan. This can improve penetration and overall results while managing irritation.

What if I see redness or stinging

Mild short-lived stinging can occur at the start. If redness or burning persists, reduce frequency to every second night and add moisturiser. Stop and contact us if irritation escalates.

Do I need to stop other products

Avoid using benzoyl peroxide or other peroxide-based products on the same areas while using hydroquinone to prevent temporary dark staining. Be cautious with strong peels or scrubs and follow your doctor’s guidance. SPF every morning is essential.