Retinol and tretinoin for dark spots

Retinoids are a family of ingredients made from vitamin A. They are best known for acne, and they also appear on every medical list of ingredients that fade dark spots. This guide looks at what the evidence says about retinol and tretinoin for dark spots, how long they take, and how to use them without causing new marks. It is part of Skinli's guide to hyperpigmentation.

The retinoid family

The American Academy of Dermatology (AAD) uses "retinoids" as a name for vitamin A products used on the skin. The ones that matter for dark spots:

Retinoid	How you get it in the US	What the sources say
Retinol	Sold without a prescription	The AAD says it is routinely used for uneven skin tone and pigmentation. Labels do not have to show the percentage
Adapalene 0.1% gel	Sold without a prescription	Approved for acne. On the AAD list of fading ingredients
Tretinoin	Prescription	Tested in the key trials on dark spots. First approved by the FDA for acne in 1971, per the AAD
Tazarotene	Prescription	On the AAD list of fading ingredients

For a full comparison of these products for acne, see Skinli's guide to retinoids for acne.

How retinoids fade dark spots

The AAD says tretinoin speeds up the turnover of skin cells at the surface and boosts collagen, which improves skin tone. On dark spots in general, the AAD says fading ingredients can fade existing spots and, in some cases, slow down the making of melanin, the pigment that causes them.

The 1993 trial described below measured this. The melanin in the treated spots fell by 23% with tretinoin, compared with 3% with a plain cream.

What the trials found

Three trials by one research group tested 0.1% tretinoin cream on different types of dark spot. Each compared tretinoin with a plain cream that had no active ingredient.

Type of spot	Trial	Result
Liver spots from sun (sun spots)	1992, New England Journal of Medicine, 58 people, daily for 10 months	Facial spots lightened in 83% on tretinoin and 29% on the plain cream. Spots that disappeared did not return for at least six months after stopping
Dark marks after inflammation, in Black patients	1993, New England Journal of Medicine, 54 people, daily for 40 weeks	Spots lightened 40% toward normal skin color with tretinoin and 18% with the plain cream
Melasma	1993, British Journal of Dermatology, 38 women, daily for 40 weeks	68% improved on tretinoin and 5% on the plain cream

Two cautions come with these results. All three trials used the 0.1% strength, which needs a prescription. And a milder strength did not repeat the result: the FDA label for Renova, a 0.02% tretinoin cream, says it did not show a benefit on mottled dark patches or lentigines, the medical name for sun spots, in its trials.

Adapalene and tazarotene

A 2010 review in the Journal of Clinical and Aesthetic Dermatology says adapalene and tazarotene have been shown in clinical studies to treat dark marks safely, particularly marks left by acne, in darker-skinned people. The AAD's acne page says a retinoid applied to the skin can help lighten dark spots after acne clears.

That makes adapalene a practical choice for acne marks. It treats the acne that causes new marks, and it helps fade the old ones. The 2024 acne guideline from the Journal of the American Academy of Dermatology gives topical retinoids a strong recommendation for acne. Skinli's plan uses adapalene 0.1% gel at night.

Retinol

Retinol has the weakest trial record of the group for dark spots. The AAD lists it among fading ingredients, and its acne page for darker skin says retinol can unclog pores and fade dark spots. No controlled trial of retinol on dark spots was found among the sources read for this guide. Retinol is milder than tretinoin, which can help people whose skin reacts to stronger retinoids.

How long it takes

Retinoids are slow, and the trials show how slow.

• Dark marks after inflammation: improvement was first noted after 4 weeks, in a 40-week trial.
• Liver spots: lightening showed after one month, in a 10-month trial.
• Melasma: significant improvement first appeared after 24 weeks, in a 40-week trial. The authors called the improvement slow.

Plan for months, not weeks. A monthly photo in the same light shows the change more clearly than the mirror does. The guide on how long dark marks take to fade gives timelines for each type of spot.

Irritation can cause new marks

Retinoids irritate the skin, especially in the first weeks. In the 1993 trial, half of the patients on tretinoin developed retinoid irritation, which eased as the study went on. In the melasma trial, 88% had redness and peeling.

On darker skin, irritation is more than a comfort problem. The AAD says irritation from a retinoid can trigger dark marks, known as hyperpigmentation, on skin of color. The 2010 review says the same thing, and suggests starting at lower strengths and choosing gentler formulas, such as creams over gels.

The AAD's advice for any retinoid:

• Start with the least intense formula you can find.
• Use it every other night at first, then build up slowly.
• Use a moisturizer.
• Apply it at night, and use sun protection during the day.

The guide on how to start adapalene turns this into a week-by-week plan. If dryness or peeling appears, retinoid dryness and peeling explains what to do.

Sun protection is part of the treatment

Retinoids make skin more sensitive to sun, the AAD says. The Renova label warns of a higher risk of sunburn and asks for sunscreen and protective clothing.

This matters twice for dark spots. Sun darkens existing spots and starts new ones. And the AAD lists medicines that make skin more sensitive to sunlight, including retinoids, among the possible triggers of melasma. A retinoid used without daily sunscreen can work against itself. The AAD recommends a tinted sunscreen with iron oxide and SPF 30 or higher for dark spots.

A simple plan for acne marks

For someone with acne and the flat marks it leaves, a retinoid can do both jobs. A plan built on the sources above looks like this:

1. Weeks 1 and 2. Adapalene 0.1% gel every other night, a thin layer over the whole area with acne, then moisturizer. Sunscreen every morning, SPF 30 or higher, tinted if you have darker skin.
2. Weeks 3 and 4. If your skin is not stinging or peeling, move to every night. If it is, stay at every other night for another week.
3. From week 5. Keep the same steps. Skinli's 12-week plan adds an azelaic acid 10% cream in the morning for people with flat marks, before sunscreen.
4. Month by month. Compare photos. Expect fewer new marks first, then lighter old marks.

Stop any product that burns or stings, as the AAD advises, and go back to a gentle routine until your skin calms down.

Retinoid or another ingredient?

A retinoid is one of five options on the AAD's list. Each has a different strength.

If you...	Consider	Why
Have active acne and marks	Adapalene	Treats the acne and helps fade marks
Find retinoids too irritating	Azelaic acid	The AAD says it treats acne and the dark spots acne leaves
Have sun spots and want the strongest evidence	Prescription tretinoin, from a doctor	The 1992 trial on liver spots
Have melasma	A dermatologist's plan	Melasma often needs combined prescription treatment
Are pregnant or planning to be	A non-retinoid option, chosen with your doctor	Retinoids should not be used in pregnancy

The azelaic acid page and the melasma page cover the other options.

Who should not use retinoids

The AAD says retinoids should not be used during pregnancy. The Renova label says not to use it if you are pregnant or trying to become pregnant. Skinli's guide to retinoids during pregnancy and breastfeeding covers the details. The AAD also advises people with skin allergies, dry skin, or a lot of redness and inflammation to ask a dermatologist before trying a retinoid.

If you already use a prescription retinoid from your doctor, keep using it as directed and ask your doctor before adding another product. The guide on what to mix with a retinoid covers which products can go together. For other ingredients that fade spots, see azelaic acid and vitamin C.