Is retinol bad for you? Side effects and safety

Retinol is sold on open shelves, so people reasonably ask whether it is safe to put on their face every night. The sources read for this guide describe three clear limits: irritation, sun sensitivity and pregnancy. They also answer the questions that come up online, about thinner skin, cancer, vitamin A poisoning and use near the eyes. This guide sets out what the American Academy of Dermatology (AAD), the FDA, the U.S. National Institutes of Health (NIH) and published studies say. It is part of Skinli's guide to retinoids for acne, and it is general education. A dermatologist can advise on your own skin.

The short answer

For most adults, the risks the sources describe are on the skin. The AAD says some ingredients, "such as retinol and glycolic acid, can irritate your skin, particularly if your skin is sensitive," and calls this "normal and temporary." Retinoids make skin more sensitive to the sun. And the AAD says "Retinoids should not be used during pregnancy." Beyond those limits, few long studies exist, and no source read shows harm inside the body from retinol put on the skin.

Irritation

The 2024 AAD acne guideline lists the side effects of topical retinoids as burning, dryness, redness, peeling and pain. In three trials of retinoid medicines, 1.4 percent of people stopped at 12 weeks because of side effects. A 2022 review in Advances in Therapy says retinoid side effects "are generally dose-dependent and manifest as 'retinoid dermatitis' or skin irritation at the application site." Dose-dependent means a stronger product or more of it tends to cause more.

Irritation matters more on darker skin. An AAD dermatologist says "With skin of color, irritation can trigger dark marks, known as hyperpigmentation," and that starting slowly and using moisturizer helps. Another AAD page warns that for darkly pigmented skin, even at-home versions of chemical peels, microdermabrasion and laser treatments can cause permanent dark marks and light spots, and advises seeing a dermatologist first.

Three habits from the AAD lower the risk:

• Start low and slow. Use the least intense product you can find, every other night at first.
• Moisturize. The AAD says a daily moisturizer helps skin tolerate retinoids. Skinli's guide to moisturizer with retinol covers which one.
• Do not exfoliate at the same time. The AAD says exfoliating while using retinol "may worsen dry skin or even cause acne breakouts."

Skinli's guide to retinoid dryness and peeling covers what to do once skin reacts.

Sun sensitivity

The AAD says "retinoids can make skin more sensitive to sun." Its advice is to use a retinoid only at night and to protect skin during the day by seeking shade, wearing sun-protective clothing such as a wide-brimmed hat, and applying sunscreen to all skin not covered by clothing. For sensitive skin it suggests a sunscreen with titanium dioxide or zinc oxide. The over-the-counter adapalene label says to "limit sun exposure, including light from tanning beds, and use sunscreen when going outdoors." Summer and holidays in the sun call for the same care, applied more strictly.

Pregnancy and breastfeeding

Retinol is covered by the pregnancy warning for retinoids. The AAD says retinoids should not be used during pregnancy. Its page on large pores says "If you're pregnant or breastfeeding, you shouldn't use a product containing retinol or retinyl palmitate," and its stretch marks page says some products contain ingredients, "such as retinol, that can harm your baby." MedlinePlus says large doses of vitamin A in pregnant women can cause birth defects; that statement is about vitamin A taken in large amounts. Skinli's guide to retinoids during pregnancy and breastfeeding sets out every source in detail.

Red, inflamed skin and rosacea

Some skin should not start with a retinoid at all. A dermatologist quoted by the AAD says, "If someone has a lot of redness or inflammation in their skin, they should avoid retinoids and ask their dermatologist about other therapies that are more directed to a condition called rosacea." The same page says people with moderate or severe acne scarring, or acne tied to periods or other hormone changes, should see a board-certified dermatologist before trying a retinoid.

Children and swallowing

The one internal risk the sources name is swallowing. MedlinePlus says "Babies and children are more sensitive to vitamin A," and "Swallowing products that contain vitamin A, such as skin cream with retinol in it, can also cause vitamin A poisoning." The adapalene Drug Facts label also says "Keep out of reach of children." Store retinol products where children cannot reach them. For teens using retinol on purpose, see Skinli's guide to retinoids for teens.

Vitamin A taken by mouth is a different risk

Much of the worry about vitamin A comes from what happens when it is swallowed. MedlinePlus says acute vitamin A poisoning most often occurs when an adult takes several hundred thousand IUs of vitamin A, and that chronic poisoning may occur in adults who regularly take more than 33,000 IU a day. Those figures are for vitamin A taken by mouth, such as supplements. The 2022 review says the risk of birth defects "has been confirmed for orally ingested retinoids," while concerns after use on the skin rest on published case reports. Retinol on the skin is a different exposure, and no source read for this guide reports internal harm from it.

Does retinol thin the skin?

The sources point in two directions. The AAD's hair removal page says waxing is not recommended if you are applying tretinoin, because "These medications thin your skin. When the wax is removed, your skin could tear." Two retinol studies measured the outer skin layer and found it thicker. A 2016 study found that 4 weeks of retinol and of retinoic acid both "increased epidermal thickness." A 2020 study found "greater epidermal thickening" with retinol serum than with tretinoin cream at 12 weeks. The adapalene label adds its own rule for waxing: "do not wax to remove hair in areas where the product has been applied."

Does retinol cause cancer?

No source read for this guide shows that retinol creams cause cancer in people. The main study on this question read for this guide is a 2012 report by the National Toxicology Program, part of the NIH. It exposed hairless mice to simulated sunlight for 40 weeks and put creams on their skin. The plain cream, with no retinoid, already raised skin tumors compared with no cream. A cream with retinyl palmitate, a storage form of vitamin A, raised them further, and a cream with retinoic acid brought skin lesions on earlier. The study covered those two forms in mice with added light. The AAD's advice for all retinoids is to use them at night and to protect skin from the sun by day.

Long-term use

Long studies of retinol are few. The longest one read for this guide, from 2015, used 0.1 percent retinol on the face for 52 weeks, and its abstract describes improvement without reporting safety results. Retinoid medicines are used for long periods on purpose: the AAD says dermatologists may recommend a topical retinoid as a maintenance treatment that "can keep your skin clear once acne is under control," and NICE says to review maintenance treatment after 12 weeks to decide whether it should continue. Skinli's guide to retinol before and after covers what the long studies found.

Who checks retinol products

Most retinol products are cosmetics. The FDA says cosmetics "do not require FDA approval before they go on the market." A 2022 law, the Modernization of Cosmetics Regulation Act, says "Companies and individuals who manufacture or market cosmetics have a responsibility to ensure the safety of their products," and requires them to report serious adverse events to the FDA within 15 business days. The FDA also says neither the law nor its rules require specific safety tests for each product or ingredient. So the testing you can do yourself matters: the AAD advises applying a new product to a test spot "twice daily for seven to 10 days" before regular use.

Near the eyes

The skin around the eyes needs extra care. The 2022 review says "the application of retinoids around the eyes may cause ocular discomfort and dry eye syndrome." MedlinePlus says not to let tretinoin get into the eyes, and the adapalene label says to avoid the eyes, lips and mouth, and to flush with water right away if contact happens.

When to stop and see a doctor

The AAD says that if a product causes a skin reaction, wash it off gently as soon as possible and do not use it again, and see a dermatologist if the reaction is severe. The adapalene label says to stop and ask a doctor for signs of an allergic reaction such as hives, swelling of the lips or eyelids, or shortness of breath, or if irritation becomes severe. If a doctor prescribed your retinoid, ask them before you stop or change it.