The smallest and most familiar AHA, used for texture, dullness and dark marks. What it does, what the research shows, how strong it can be at home, and what 11 skincare experts said about it on camera.
Glycolic acid promises smoother, brighter skin, and it turns up in everything from toners to body lotions. But how strong should it be? Can you use it every night? Why does everyone keep telling you to wear sunscreen with it? Is it safe on darker skin? And what happens when your cleanser, toner and serum all contain acids?
So what do the experts actually say? Most of the experts we follow like it for rough texture, dull skin and dark marks, on the face and the body. Where they get cautious is in how it is used, and on whom.
That is why glycolic acid's own Guru Score, 64%, is lower than you might expect for such a familiar ingredient. The score counts every verdict from 24 mentions by 11 experts, among them dermatologists, a cosmetic surgeon and a medical esthetician, and the doubts are specific. It is easy to over-exfoliate when it is stacked with other acids, and some experts are wary of it on darker skin tones, where irritation can leave dark marks behind. Below, what the experts said sits next to what the studies and regulators say, so you can see where the two line up.
Glycolic acid is an exfoliating acid (an AHA) used to smooth rough texture, brighten dull skin and help fade dark marks. The experts we follow mostly recommend it, with their doubts aimed at stacking acids and at darker skin tones. Small trials found it modestly improved sun-damaged skin [5, 6]. Its main drawback is sun sensitivity: in one study, 10% glycolic acid made skin burn more easily under UV light [4], so the US FDA advises sunscreen while you use it and for a week afterwards [1].
| Question | What we found |
|---|---|
| What is it used for? | Rough texture, dullness, uneven tone, dark marks and signs of sun damage, on the face and body [1, 2]. |
| Do skincare experts recommend it? | Mostly, with care. Their doubts are about doubling up on acids and about darker skin tones. |
| What kind of acid is it? | An alpha hydroxy acid (AHA). It is the simplest one, and one of the two AHAs most used in cosmetics, with lactic acid [1, 3]. |
| How strong is it at home? | US safety reviewers judged consumer products safe at 10% or less with a pH of 3.5 or higher. Stronger peels belong with trained professionals [1, 2]. |
| Does it make you sun sensitive? | Yes. Use sunscreen while you use it and for a week after you stop [1, 4]. |
| Is it safe in pregnancy? | Little reaches the bloodstream from skincare, so it is not thought to be a concern, but it has not been studied in pregnancy. Ask your doctor or midwife [11]. |
Glycolic acid is an alpha hydroxy acid, or AHA. It is the simplest member of the family, and the first to be used in skincare [3]. Like the other AHAs, it loosens the bonds between dead cells on the surface of the skin so they shed more easily, which leaves skin looking smoother and more even [2].
How much it exfoliates depends on three things: the strength, the pH of the product, and what else is in the formula [1]. That is why a 3.5% wash and a clinic peel can share an ingredient and behave nothing alike.
It is a small molecule. Small AHAs such as glycolic and lactic acid get into the skin more readily, while larger ones such as mandelic acid tend to be gentler on sensitive skin [2]. That size is the reason some of our experts like it, and the reason others are wary.
Here is what each of them said on camera, with a link to the moment they said it.
Alpha hydroxy acids include commonly glycolic, lactic, and mandelic. [...] These are water loving. They help exfoliate the epidermis and in doing so they can help lighten hyperpigmentation.Watch ▸
I have been using this cleanser in my own routine for years. It's a 3.5% pure Glycolic Acid Cleanser, fragrance-free [...] It's a generally low concentration of glycolic acid at only 3.5%, and it's only on your skin for like a minute before you rinse it off. So all skin types can use this.Watch ▸
If your skin is either a combination or oily or you suffer from hyperpigmentation glycolic acid is going to be your jam. [...] Exfoliating acids in my opinion are best used at bedtime because your exfoliating acid is going to take off that top layer of the skin, and the new layer skin that's underneath is very prone to sunburn and sensitivity so making sure that it's properly protected especially with your sunscreen in morning it's going to be extremely important.Watch ▸
This is a ten percent glycolic acid serum with tranexamic acid in it. [...] If you're using a chemical exfoliant, do not use this. If you're not using a chemical exfoliant, use this in your routine, but do not double dip, otherwise you're going to be over-exfoliating your face and burning your face off in the process.Watch ▸
This is a glycolic acid lactic toner that has got a mixture of different acids in there, so if you suffer from acne for example as well as maybe some light pigmentation it can be quite nice. Glycolic acid for darker skin types you have to be a little bit careful just because of irritation and pigmentation.Watch ▸
This means it doesn't just exfoliate, it rushes into the skin. In darker skin tones, this rapid penetration causes a shock response. [...] I've seen countless patients darken their melasma because they were over exfoliating with glycolic acid. The fix is to switch to lactic acid or mandelic acid or even phytic acid.Watch ▸
Most of the experts back it, but not without conditions, so the caveats are where the useful detail sits.
The best known trial is on sun-damaged skin. In a 22 week study of 74 women aged 40 to 70, 76% of those using an 8% glycolic acid cream on the face improved by at least one grade, against 40% on the plain cream [5]. Lactic acid at the same strength did about as well, and the authors called both modestly useful [5].
Smaller studies looked below the surface. In a pilot study, about six months of a 25% AHA lotion on the forearm thickened the skin by roughly a quarter and increased the density of collagen [6]. Another found 20% glycolic acid lotion, used twice a day for three months, raised collagen gene activity and hyaluronic acid in the skin [7]. Those strengths are higher than most face products, and the studies are small, so treat collagen claims as promising rather than proven.
For dark marks, most of the evidence comes from professional peels rather than everyday products. In two small trials in people with darker skin, adding a course of glycolic acid peels to a prescription cream improved post-inflammatory hyperpigmentation (the dark marks left by spots and irritation) more than the cream alone: clearly in one trial, and as a trend in the other [8, 9].
The clearest downside is the sun. In a small study, 3.5 weeks of 10% glycolic acid made skin more sensitive to UV, with more redness, more DNA damage and more sunburn cells, while 2% salicylic acid did not [4]. FDA research found the effect wears off within about a week of stopping [1].
In the US, the Cosmetic Ingredient Review panel concluded that glycolic acid products for consumers are safe at 10% or less, with a final pH of 3.5 or higher, if they protect against sun sensitivity or tell you to use sun protection daily [1]. Salon products can go up to 30% at a pH of 3.0 or higher, for brief use followed by thorough rinsing, applied by trained professionals [2]. Stronger peels are a medical treatment [2].
Most cleansers, toners and serums sit in the consumer range, and a wash-off product spends only a minute or so on the skin. Professional peels are a different tool: the trials on dark marks used peels of up to 68% under supervision [8]. Dr. Aanchal MD, a dermatologist, keeps glycolic acid creams for maintenance at home and starts them slowly.
Reports to the FDA have included burns, blisters and pigment changes, and the more serious reactions came most often from the products that exfoliate hardest [1]. A stronger product is not a better one if your skin cannot tolerate it.
The FDA's recommended label wording for AHA products is a sunburn alert: use sunscreen, wear protective clothing and limit sun exposure while using the product and for a week afterwards [1]. Dr. Aleksandra Brown puts exfoliating acids at bedtime for the same reason, and makes sunscreen the next morning non-negotiable.
Our experts disagree here. Nipun Kapur, a skincare consultant, treats glycolic acid as a grey area and avoids it for the nine months of pregnancy, though she is happy with it while nursing.
A review for family doctors says glycolic acid has not been studied in human pregnancy, but that topical use should not be a concern because only a minimal amount is expected to reach the bloodstream [11]. The animal studies that raised worries used doses far larger than skincare delivers [11]. If you are pregnant or breastfeeding, check with your doctor or midwife first.
This is where our experts part ways. Dr. Vanita Rattan, a doctor who specialises in skin of colour, is firmly against it: she says its small size lets it rush into the skin and trigger inflammation that leaves darker patches, and she steers people to lactic, mandelic or phytic acid instead. Dr. Somji, a cosmetic surgeon, takes a softer line: be a little careful with glycolic acid on darker skin because of irritation and pigmentation.
The worry is a real one. Any irritation in deeper skin tones can leave post-inflammatory hyperpigmentation, and a review notes that combining glycolic acid peels with microdermabrasion in the same session could cause it in skin types III to VI [2]. In a small study, glycolic acid also increased tanning after UVB exposure in Asian and white volunteers [3].
The research is not all cautionary, though. Two small supervised trials in people with darker skin (Fitzpatrick types III to VI) found serial glycolic acid peels added to the benefit of a prescription cream for dark marks, with side effects that were minimal or manageable [8, 9]. In one, the peels also lightened the surrounding normal skin [8].
Start with a low strength a few times a week and build up only if your skin stays comfortable. Stop for a few days if your skin gets dry or irritated [10].
A cleanser is the gentlest way in. The Budget Dermatologist uses a 3.5% glycolic acid wash herself and says it suits all skin types because it is low strength and rinsed off within a minute. Leave-on toners and serums give a stronger effect, and that is where doubling up becomes a risk.
Night is the common choice. Dr. Aleksandra Brown prefers bedtime for exfoliating acids, because the fresh layer of skin underneath is prone to sunburn and sensitivity. Wherever it sits, wear sunscreen in the day [1].
Glycolic acid is popular below the neck. The American Academy of Dermatology lists it among the exfoliating ingredients for keratosis pilaris, the rough little bumps on the upper arms and thighs, alongside lactic acid, salicylic acid and urea [10]. Dr Dray notes that most of the research on keratosis pilaris is on glycolic or lactic acid.
Dr. Aanchal MD suggests glycolic acid creams for buttock acne and dark marks, starting twice a week and moving to alternate nights if your skin tolerates it. HotandFlashy swears by a glycolic acid body lotion for dry, crepey skin. Dr. Vanita Rattan warns against using it under the arms on darker skin, where she has seen it cause burns. We found no studies of underarm use.
The rule that matters most is not to stack exfoliants by accident. Dr. Shereene Idriss warns that using a glycolic acid serum on top of another chemical exfoliant is a quick route to over-exfoliated, burning skin, and Cassandra Bankson, a medical esthetician, gives the same warning about adding extra acids to an AHA and BHA peel.
Close cousins. In the 22 week trial on sun-damaged skin, 8% lactic acid did about as well as 8% glycolic acid [5]. Dr Dray explains that glycolic acid is smaller, so it gets into the skin more readily and may work a little better for some people, but may also irritate more, while lactic acid tends to be gentler and also holds water in the skin. If your skin is dry, sensitive or deeper in tone, lactic acid is the easier starting point. Our lactic acid guide has more.
Salicylic acid is fat soluble, which suits oily, clogged pores [3]. In the same UV study, 10% glycolic acid raised sun sensitivity and 2% salicylic acid did not [4]. As peels for acne, a review reports that 30% glycolic and 30% salicylic acid worked similarly in one split-face trial, with salicylic acid lasting longer and causing fewer side effects [2]. Dr. Aleksandra Brown matches them to skin: glycolic acid for combination skin and pigmentation, salicylic acid for oily, acne-prone skin. Our salicylic acid guide has more.
Plenty of routines use both. Kelly Driscoll counts on retinol, glycolic acid and peptides together to stimulate collagen, and the dark-mark trials paired glycolic acid with tretinoin under a doctor's care [8, 9]. Both can irritate, so let your skin settle into one before you bring in the other, and use them on different nights to begin with. Our retinol guide has more.
Some dark spot serums combine the two, including the 10% glycolic acid serum with tranexamic acid that Dr. Shereene Idriss rates for pigmentation. Treat it as your exfoliant for the day, not an extra one. Our tranexamic acid guide has more.
The best one for you depends on your skin and your budget, so here is the top-rated pick for each need, from the products below.
Good MoleculesAll-In-One Exfoliating Treatment
Smooths texture and brightens at a low price
88%Guru Score from 5 experts
Best budget pick
L'Oreal3.5% Pure Glycolic Acid Cleansing Gel
Gentle entry point for glycolic acid
87%Guru Score from 2 experts
Best for oily skin
Paula's ChoiceSkin Perfecting 25% AHA + 2% BHA Exfoliating Peel
Purple iridescent finish
85%Guru Score from 7 experts
Best for dry skin
GlytoneExfoliating Body Lotion (Glycolic Acid)
Strong glycolic formulation
86%Guru Score from 2 expertsA high score for the ingredient does not carry over to every product that contains it. Strength, pH and what else is in the bottle all change the verdict. These are the highest-scoring glycolic acid products that at least two experts have rated, ranked by Guru Score.
Good MoleculesAll-In-One Exfoliating Treatment
Rated by 5 experts
The catch: Overnight only, not for daytime use
88%Guru Score
L'Oreal3.5% Pure Glycolic Acid Cleansing Gel
Rated by 2 experts
87%Guru Score
NaturiumSmoother Glycolic Acid Body Wash
Rated by 4 experts
86%Guru Score
GlytoneExfoliating Body Lotion (Glycolic Acid)
Rated by 2 experts
86%Guru Score
L'OréalGlycolic Gloss Shampoo
Rated by 2 experts
85%Guru Score
Paula's ChoiceSkin Perfecting 25% AHA + 2% BHA Exfoliating Peel
Rated by 7 experts
The catch: Expensive for the size
85%Guru Score
The INKEY ListGlycolic Acid Exfoliating Body Stick
Rated by 3 experts
The catch: Less effective on hairy areas without rubbing in
85%Guru Score
Paula's Choice10% Glycolic Body Blend
Rated by 2 experts
The catch: Strong enough to warrant a slow start
85%Guru Score
Dr. IdrissMajor Fade Flash Mask
Rated by 4 experts
The catch: Very expensive for the amount
84%Guru Score
CeraVeSkin Renewing Nightly Exfoliating Treatment
Rated by 4 experts
The catch: Can sting, especially around eyes and mouth
84%Guru Score
CeraVeAcne Control Gel with Salicylic Acid
Rated by 4 experts
The catch: May irritate deeper skin tones, patch test first
84%Guru ScoreGlycolic acid loosens the dead cells on the surface of your skin so they shed more easily, which smooths rough texture and brightens dull, uneven skin [1, 2]. In a 22 week trial, an 8% cream modestly improved sun-damaged skin [5]. Most of the skincare experts we follow recommend it, with care.
Some people can, especially with a gentle wash, but build up to it. The Budget Dermatologist uses a 3.5% glycolic acid cleanser daily and says all skin types can use it. Leave-on products are stronger, so start two or three times a week and increase only if your skin stays comfortable. Wear sunscreen every day while you use it [1].
For home use, US safety reviewers judged products safe at 10% or less with a pH of 3.5 or higher [1]. Washes and toners often sit well below that, and a low strength is the sensible start. Salon peels can go up to 30%, applied by trained professionals and rinsed off [2]. Anything stronger is a medical treatment.
Yes. In a small study, 3.5 weeks of 10% glycolic acid increased sunburn redness, DNA damage and sunburn cells after UV exposure [4]. FDA research found the extra sensitivity fades within about a week of stopping [1]. The FDA recommends sunscreen, covering up and limiting sun exposure while you use it and for a week afterwards [1].
It can be, with care, but this is where the experts disagree. Dr. Vanita Rattan avoids it for skin of colour and prefers lactic or mandelic acid, while Dr. Somji says to be a little careful. Small supervised trials of glycolic acid peels in darker skin found benefits with manageable side effects [8, 9], but irritation can leave dark marks [2], so start low and slow.
They are close. In a 22 week trial on sun-damaged skin, 8% lactic acid did about as well as 8% glycolic acid [5]. Dr Dray explains that glycolic acid is smaller, so it may work a little better for some people but may irritate more, while lactic acid tends to be gentler. Dry, sensitive or deeper-toned skin may do better starting with lactic acid.
Glycolic acid is an AHA that works on the surface for texture and tone. Salicylic acid is fat soluble, so it suits oily skin and clogged pores [3]. In one small study, glycolic acid raised sun sensitivity while salicylic acid did not [4]. Dr. Aleksandra Brown points combination and pigmented skin to glycolic acid, and oily, acne-prone skin to salicylic acid.
It can help, slowly. Faster shedding of the surface cells is thought to disperse pigment more quickly [3], and Dr Dray says AHAs can help lighten hyperpigmentation. The stronger evidence is for professional glycolic acid peels used alongside a prescription cream for dark marks [8, 9]. Daily sunscreen matters more than ever, because glycolic acid can increase tanning after UV exposure [3].
Modestly. In a 22 week trial, 76% of women using an 8% glycolic acid cream improved by at least one grade of sun damage, against 40% on a plain cream [5]. Small studies at 20% to 25% found thicker skin and more collagen activity on the forearm [6, 7]. Kelly Driscoll counts it among the ingredients she uses for firmer skin.
It has not been studied in pregnant women, but a review for doctors says topical glycolic acid should not be a concern because only a minimal amount is expected to reach the bloodstream [11]. Nipun Kapur takes the cautious route and avoids it for the nine months of pregnancy. Check with your doctor or midwife, and skip strong peels.
Yes, and it is popular there. The American Academy of Dermatology lists glycolic acid among the exfoliating ingredients for keratosis pilaris [10]. Dr. Aanchal MD suggests glycolic acid creams for buttock acne and dark marks, starting twice a week, and HotandFlashy uses a glycolic acid body lotion for dry, crepey skin. Remember sunscreen on any treated skin that sees the sun.
Be cautious. Glycolic acid under the arms has been passed around as a brightening hack, but Dr. Vanita Rattan warns that on darker skin it can cause chemical burns, and she advises against it. We found no studies of underarm use, so there is no evidence it is worth the risk. If you try it anyway, use a low strength and stop at any stinging or burning.
Many people do, but both can irritate, so introduce one at a time and use them on different nights to begin with. Kelly Driscoll uses glycolic acid alongside retinol and peptides. In the dark-mark trials, glycolic acid was paired with prescription tretinoin under a doctor's care [8, 9]. If your skin gets dry or stings, cut back.
Think in months, not days. The trial on sun-damaged skin ran for 22 weeks [5], one dark-mark peel trial judged results at 21 weeks [9], and the collagen study used glycolic acid twice a day for three months [7]. Steady use with daily sunscreen matters more than reaching for a stronger product.
11 experts, 24 mentions, every one traced to a video you can watch. Sponsored takes are excluded.
This guide combines two kinds of information. The expert consensus comes from 24 mentions of glycolic acid by 11 skincare experts in their YouTube videos. Each one was read, given a Yay, Mixed or Nay verdict and linked to the moment it was said. Sponsored takes are excluded. The research sections summarise published studies, regulations and medical sources, listed in full above.
The Guru Score measures how warmly the experts talk about glycolic acid. It is not a measure of clinical effectiveness, and this guide is not medical advice. It has not been reviewed by a doctor.
This guide is general information, not medical advice. The Guru Score reflects how warmly the experts we track talk about glycolic acid; it is not a measure of clinical efficacy. Speak to a dermatologist or doctor about a diagnosed skin condition, and before using any medicine.
HotandFlashy
Kelly Driscoll
Nipun Kapur