Does tretinoin help acne scars? What studies show

Tretinoin is a prescription retinoid, a medicine made from vitamin A that speeds up how fast skin cells turn over. Many people start it hoping it will smooth acne scars. The medical sources give a limited answer: the American Academy of Dermatology (AAD) says that "if you have mild acne scarring, a retinoid or salicylic acid can make scarring less noticeable." For moderate and deep scars, the AAD lists procedures. This guide covers what the studies found for tretinoin and related retinoids, how to use tretinoin safely, and how it is used before and after scar procedures. For every treatment option, see acne scar treatment.

Scars and dark marks respond differently

Retinoids do two different jobs, and it helps to know which one you want.

• Flat dark or red marks. These are color changes, and the AAD says they usually fade. Retinoids can help them fade faster. The guide retinol and tretinoin for dark spots covers that use.
• Scars. These change the shape of the skin: a dent or a bump. Here, retinoids have a smaller role, limited to mild sunken scars and to preventing new scars by clearing acne.

The AAD's overview says that when a scar first appears, "you may see a depression (indent in your skin) or a raised scar, along with some discoloration. Over time, the discoloration usually goes away. However, the scar remains." So if tretinoin seems to improve a scar, part of what you see may be the color fading.

What tretinoin is approved for

The label for Retin-A, a tretinoin cream and gel, says it is approved to be applied to the skin to treat acne vulgaris, the medical name for ordinary acne. It adds that its safety and effectiveness for long-term use in other conditions "have not been established." Using tretinoin for scars is a choice your doctor makes beyond that approved use.

Tretinoin belongs to a family. Retinol is a retinoid found in many skin care products. Adapalene is a retinoid that the AAD lists among treatments you can buy without a prescription. Tazarotene and trifarotene are two more retinoids, tested in the studies below. The guide retinol vs retinoid explains the differences, and prescription retinoids for acne covers how to get tretinoin.

NIAMS, part of the U.S. National Institutes of Health, says topical retinoids "can also help prevent the formation of acne and help with scarring."

What the studies found

The research on retinoids and acne scars is small. Here are the main studies, with their limits:

Study	What was tested	Result	Limits
1999, International Journal of Dermatology	Tretinoin 0.025 percent gel pushed into scars with a small electric current, twice a week for 3 months, in 32 people	Scar depth decreased in 94 percent	No comparison group; a clinic method, unlike cream at home
2018, American Journal of Clinical Dermatology	Adapalene 0.3 percent with benzoyl peroxide 2.5 percent on one half of the face, a gel without active ingredients on the other, for 24 weeks, in 67 people with moderate or severe acne	Scar count fell 15.5 percent on the treated side and rose 14.4 percent on the other	Funded by the gel's maker
2019, JAMA Facial Plastic Surgery	Tazarotene 0.1 percent gel every night on one side of the face, microneedling on the other, for 3 months, in 36 people	Both sides improved by similar amounts at 6 months	Small; no untreated comparison
2023, Dermatology and Therapy	Trifarotene on one side of the face, a gel without active ingredients on the other, for 24 weeks, in 121 people with acne and scars	Scar count fell by 5.9 on the treated side and by 2.7 on the other	Three authors were employees of Galderma, a drug company

The 2017 review in Scars, Burns and Healing adds one more: in 35 people who used tretinoin 0.025 percent with glycolic acid 12 percent for 12 weeks, 3 showed no improvement, 16 improved mildly, 13 moderately, and 3 more than that. That study looked back at records and had no comparison group.

The size of the change matters as much as the direction. In the 2018 trial, people started with an average of 12 scars per half face. After 24 weeks, the treated side averaged 9.5 scars and the other side 13.3. In the 2018 trial, 32.9 percent of treated sides were rated clear or almost clear of scars, compared with 16.4 percent of the other sides. In the 2023 trifarotene trial, 31.3 percent of treated sides reached success on the doctors' scar rating at week 24, compared with 8.1 percent. In both trials, most treated sides did not reach that top rating.

Two reviews put these results in context. A 2023 review of creams and gels for acne scars in the Journal of Cosmetic Dermatology concluded that there is a "lack of evidence to support the widespread use" of creams and gels for acne scars. A 2016 Cochrane review found a lack of high-quality evidence for every acne scar treatment.

What about retinol?

Retinol is the retinoid most people can buy in a store. This guide found no study of retinol on sunken acne scars in the medical sources it checked. The AAD's page on fading dark spots lists retinol among the retinoids that can help flat dark marks. For dents, the studies that exist tested tretinoin, adapalene, tazarotene and trifarotene, and even those show modest results. See retinoids for acne.

Where retinoids help most: stopping new scars

The 2018 trial suggests the clearest benefit of a retinoid gel is prevention. On the side given a gel without medicine, the scar count rose 14.4 percent in 24 weeks as acne kept leaving new scars. On the treated side, it fell. The AAD says: "Treat acne when you first notice it and continue treatment. Preventing acne can prevent acne scars."

That is the reason Skinli's plan starts with acne itself. The free Skinli acne plan uses adapalene 0.1 percent and benzoyl peroxide 2.5 percent, each every other night for two weeks and then every night, and tells you when to see a doctor.

How to use tretinoin

These steps come from the Retin-A label. Your doctor may change them.

• Once a day, at bedtime. Apply "to the skin where acne lesions appear, using enough to cover the entire affected area lightly."
• Keep it away from "the eyes, the mouth, angles of the nose, and mucous membranes."
• Expect irritation at first. "During the early weeks of therapy, an apparent exacerbation of inflammatory lesions may occur." In plain words, acne may look worse at first. Redness and peeling are common; if irritation is strong, the label says to use it less often or stop for a while. The guide retinoid dryness and peeling covers how to manage it.
• Use a thin layer. "If medication is applied excessively, no more rapid or better results will be obtained and marked redness, peeling, or discomfort may occur."
• Limit sun. The label says to minimize sun exposure, not to use tretinoin on sunburned skin until it heals, and to use sunscreen and protective clothing when you cannot avoid the sun. It also reports temporary darker or lighter skin with repeated use.
• Pregnancy. The label says tretinoin "should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus." See retinoids during pregnancy and breastfeeding.

On timing, the label says acne "results should be noticed after 2 to 3 weeks but more than 6 weeks of therapy may be required." The scar studies above ran for 12 to 24 weeks, so judge scar changes over months.

Tretinoin around scar procedures

If you plan a procedure, tell the dermatologist you use tretinoin. The AAD gives different instructions for different procedures:

• Laser. The AAD says to "stop using skin care products that contain a retinoid or glycolic acid for 2 to 4 weeks" before laser treatment of a scar. See laser treatment for acne scars.
• Microneedling. The pre-treatment routine "may include stopping use of retinoids (i.e., retinol and tretinoin) or other ingredients found in skin care products for a few days." See microneedling for acne scars.
• Chemical peel. Here, a retinoid may be part of the preparation. The AAD says "pre-peel priming can include taking an antiviral medication or applying a retinoid," for 2 to 4 weeks. The 2017 review says tretinoin is often used before medium and deep peels to help the acid go in evenly and lower the risk of dark patches. See chemical peels for acne scars.

Follow your own dermatologist's instructions, since they depend on the procedure and your skin.

When to see a dermatologist

See a dermatologist if you have dents that bother you, if acne keeps leaving new scars, or if you want to try tretinoin, which needs a prescription. For deep scars, a cream alone is unlikely to be enough, and the dermatologist can plan procedures. Skinli gives general education and is not a doctor.