The gentler AHA that exfoliates and holds on to water. What it does, what the research shows, how it compares with glycolic and mandelic acid, and what 5 skincare experts said about it on camera.
You want to try an exfoliating acid, but your skin is dry, a little sensitive or deeper in tone, and glycolic acid sounds a bit fierce. Is lactic acid really the gentle one? Does it moisturise, or does it just peel? Can it help with cracked heels and those rough bumps on your arms? And will it still sting?
Short version: the experts we follow like it, and they know what they want it for. It is their first acid for dry and sensitive skin, their gentler swap for glycolic acid on darker skin, and a helper in thick creams for cracked heels and rough, bumpy arms.
Lactic acid's own Guru Score is 100%, from 9 mentions by 5 experts, among them dermatologists, a doctor who specialises in skin of colour and a skincare consultant. Their cautions are practical: do not pile it on top of other acids, wear sunscreen, and one expert skips it in pregnancy. Below, what the experts said sits next to what the studies and regulators say, so you can see where the two line up.
Lactic acid is a gentle exfoliating acid (an AHA) that smooths rough, dry skin and also helps it hold on to water. The experts we follow recommend it, especially as a first acid for dry and sensitive skin. In a 22 week trial, an 8% lactic acid cream modestly improved sun-damaged skin [6], and lactate lotions have done well for very dry skin [11]. Like other AHAs, it can make skin more sensitive to the sun, 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? | Gentle exfoliation for dull, rough or dry skin, plus dry heels, keratosis pilaris and signs of sun damage [2, 6, 8]. |
| Do skincare experts recommend it? | Yes, especially as a gentle first acid for dry or sensitive skin. |
| What kind of acid is it? | An alpha hydroxy acid (AHA), and with glycolic acid one of the two most common AHAs in cosmetics [1]. It is larger than glycolic acid, so it gets into the skin less deeply [2]. |
| Does it hydrate as well as exfoliate? | Yes. Lactate is part of the skin's own natural moisturising factor, and lactic acid has raised the skin's ceramide levels in a study [4, 5]. |
| Does it make you sun sensitive? | AHAs can. Use sunscreen while you use it and for a week after you stop [1]. |
| Is it safe in pregnancy? | Little of it gets through the skin, and low strengths have been used for acne in pregnancy without reported harm, but the research is thin. Ask your doctor or midwife [17]. |
Lactic acid is an alpha hydroxy acid, or AHA. Along with glycolic acid, it is one of the two AHAs you will meet most often in cosmetics [1]. Like the rest of the family, it loosens the bonds between dead cells on the surface of the skin so they shed more easily, which smooths rough patches and brightens dull skin [2].
It does a second job too. Lactate is one of the substances in the skin's natural moisturising factor, the mix that draws water into the outer layer and keeps it supple [4]. In one study, the L form of lactic acid (the one most skincare uses) raised ceramide levels in the outer layer of the skin by 48%, which improved its barrier and its resistance to dryness [5]. That is why it turns up in body lotions and foot creams as well as face serums.
Size matters with AHAs. Lactic acid is larger than glycolic acid, so it gets into the skin less deeply, which lowers the risk of irritation and makes it a common pick for dry and sensitive skin [2]. Mandelic acid is larger still and slower again [2].
Here is what each of them said on camera, with a link to the moment they said it.
The fix is to switch to lactic acid or mandelic acid or even phytic acid. These are larger molecules, they exfoliate slowly and politely without waking up your pigment cells.Watch ▸
If your skin is dry and sensitive and you want to start an exfoliating acid look for something with either mandelic or lactic acid. [...] 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.Watch ▸
Studies on 10% lactic acid, for example, show a 66% improvement in skin texture, pigmentation, and the overall appearance of the skin within a few months of consistent use.Watch ▸
If you have very dry skin, then your hand and feet tend to be more dry than the rest of the body. And I feel that you will require something thicker with ingredients such as urea and lactic acid to help in reducing the cracking from the heels and on the fingertips.Watch ▸
Lactic acid is good for normal to dry skin, it exfoliates your skin's top layerWatch ▸
The experts are on its side, 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, 71% of those using an 8% lactic acid cream on the face improved by at least one grade, against 40% on the plain cream, about level with 8% glycolic acid [6]. On the forearms it also helped dark patches, sallowness and roughness. The authors called both acids modestly useful, and well tolerated [6].
Strength makes a difference. In a three month study, 12% lactic acid used twice a day made the skin firmer and thicker in both its outer and deeper layers, smoothed it and softened the look of lines, while 5% changed only the outer layers [7].
For rough, bumpy skin the evidence is encouraging. In a trial in keratosis pilaris, a 10% lactic acid cream used twice a day for 12 weeks reduced the bumps by 66%, against 52% for a 5% salicylic acid cream, with only mild irritation [9]. A 2025 review found lactic and glycolic acids were the topicals most often preferred for the condition [10].
Dr Dray quotes a figure of 66% for 10% lactic acid. That matches the keratosis pilaris trial, which measured the bumps themselves; its summary does not report on pigmentation, so treat the figure as a result for bumpy skin rather than for dark marks [9].
This is where lactic acid has the longest track record. Lotions with 12% ammonium lactate, a neutralised form of lactic acid, have been tested on very dry skin for decades. In a 21 day trial in 60 people with moderate to severe dry skin, a 12% lactate lotion, a 5% lactic acid lotion and a plain emollient all helped, but the 12% lactate kept the skin better for longer once treatment stopped [11]. In ichthyosis, an inherited condition of scaly skin, 12% lactate lotion beat both its plain base and a petrolatum cream over four weeks [12].
Dr. Aanchal MD, a dermatologist, suggests a thicker cream with urea and lactic acid for very dry hands and feet, applied in a good layer at night to help with cracked heels and fingertips. That fits the research on lactate lotions for dry skin [11].
The American Academy of Dermatology lists lactic acid among the moisturising and exfoliating ingredients used for keratosis pilaris, the rough little bumps on the upper arms and thighs [8]. Dr Dray rates AHAs as fantastic for those bumps, and points out they can sting on irritated skin, more so at higher strengths. The AAD advises stopping for a few days if your skin gets dry or irritated, and giving a plan 4 to 6 weeks before judging it [8].
Dr Dray rates a nail product with urea and lactic acid for fungal nail infections, mainly to clear the flaky build-up and help an antifungal get in. In a 24 week trial in 493 people, a solution of urea, propylene glycol and lactic acid cleared the fungus in 27% of those with milder nail involvement, against 10% on placebo [18]. If the infection is more than mild, see a doctor.
Gentler is not the same as never stinging. Lactic acid is the acid researchers use to provoke stinging in a standard test for sensitive skin, the lactic acid sting test [15, 16]. In one trial, a ceramide cream that repaired the skin barrier reduced that sting over four weeks [15]. If your skin is reactive, start with a low strength.
Dr. Vanita Rattan, a doctor who specialises in skin of colour, steers people away from glycolic acid and towards lactic, mandelic or phytic acid, because the larger molecules exfoliate more slowly. For exfoliation she suggests 5% lactic acid with 5% mandelic acid, followed by a rich moisturiser.
The research leans the same way but is thin. In a small study of 12 people with melasma and skin type IV, full strength lactic acid peels improved the patches with no recorded side effects [13]. In lab studies, lactic acid also slowed melanin production in pigment cells [3]. But a 2025 trial in 40 people with melasma found 50% glycolic acid peels worked better than 80% lactic acid peels, with no clear difference in side effects [14]. Gentle, then, but not automatically the better pigment treatment.
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 it gets dry or irritated [8]. Dr. Aanchal MD warns that too many acids on dry skin can damage the barrier further, so use one exfoliant, not several.
Night is the usual choice. Dr. Aleksandra Brown, a dermatologist, puts exfoliating acids at bedtime because the fresh skin underneath is prone to sunburn and sensitivity, and makes sunscreen the next morning essential. The FDA's label wording for AHA products asks for sunscreen, protective clothing and less sun while you use them and for a week afterwards [1].
Nipun Kapur, a skincare consultant, matches lactic acid to normal and dry skin, glycolic acid to oily skin and mandelic acid to sensitive skin. She also names a gentle lactic acid serum as one teenagers can use.
Our experts take different lines here. Nipun Kapur treats lactic acid as a grey area and avoids it for the nine months of pregnancy, because many products do not state their strength, though she is happy with it while nursing.
A review of cosmetic procedures in pregnancy notes that lactic acid shows negligible penetration into the skin, and that 2% lactic acid has been used for acne in pregnancy with no reported risk to the baby, though that evidence is anecdotal [17]. If you are pregnant, check with your doctor or midwife first.
The rule that matters most is not to stack exfoliants by accident. Choose one acid that suits your skin, and add other actives one at a time.
Close cousins. In the 22 week trial on sun-damaged skin, 8% lactic acid did about as well as 8% glycolic acid [6]. Glycolic acid is smaller and gets in more deeply; lactic acid is gentler and better suited to dry and sensitive skin [2]. For melasma peels, glycolic acid came out ahead in one trial [14]. Dr. Aleksandra Brown points dry, sensitive skin to lactic or mandelic acid and oily or pigmented skin to glycolic acid. Our glycolic acid guide has more.
Mandelic acid is the larger molecule, so it penetrates slowly and is less likely to irritate [2]. Dr. Vanita Rattan uses the two together at 5% each for darker skin. We found no trial comparing them head to head.
Salicylic acid is a BHA, the usual pick for oily, clogged skin. In keratosis pilaris, 10% lactic acid reduced the bumps a little more than 5% salicylic acid (66% against 52%), and both were well tolerated [9]. Our salicylic acid guide has more.
Both can irritate. Dr. Aleksandra Brown suggests that dry, sensitive skin alternates them, lactic or mandelic acid one night and retinol the next, rather than layering them. Our retinol guide has more.
A good match. Lactic acid itself has raised ceramide levels in the skin [5], and in one trial a ceramide cream made skin less reactive to lactic acid's sting [15]. Dr. Vanita Rattan follows exfoliation with a rich, ceramide moisturiser. Our ceramides guide has more.
Lactic acid loosens dead cells on the surface of your skin so they shed more easily, which smooths rough texture and brightens dull skin [2]. It also helps skin hold water, since lactate is part of the skin's natural moisturising factor [4]. In a 22 week trial, an 8% cream modestly improved sun-damaged skin [6]. The experts we follow recommend it.
It is one of the gentler acids, because it is larger than glycolic acid and gets into the skin less deeply [2]. Dr. Aleksandra Brown suggests it as a first acid for dry, sensitive skin. But it can still sting: researchers use lactic acid in a standard sting test for sensitive skin [15, 16]. Start with a low strength a few times a week.
Yes, as well as exfoliating. Lactate is one of the water-attracting substances in the skin's natural moisturising factor [4], and in one study lactic acid raised ceramide levels in the outer layer of the skin by 48%, improving its barrier [5]. Dr. Aanchal MD picks it for dry skin because it gives gentle exfoliation and moisture together.
They are close. In a 22 week trial on sun-damaged skin, 8% lactic acid did about as well as 8% glycolic acid [6]. Glycolic acid is smaller and gets in more deeply, while lactic acid is gentler and suits dry and sensitive skin [2]. For melasma peels, glycolic acid did better in one trial [14]. Dr. Vanita Rattan prefers lactic acid for darker skin.
Both are AHAs, and mandelic acid is the larger molecule, so it penetrates more slowly and is less likely to irritate [2]. Lactic acid adds more moisture, which suits dry skin. Nipun Kapur matches lactic acid to normal and dry skin and mandelic acid to sensitive skin, and Dr. Vanita Rattan uses 5% of each together for darker skin.
Some people can, but build up to it. Start two or three times a week and increase only if your skin stays comfortable, and stop for a few days if it gets dry or irritated [8]. Dr. Aanchal MD warns that too many acids on dry skin can damage the barrier, so keep it as your only exfoliant. Wear sunscreen daily [1].
It can. Lactic acid is an AHA, and FDA research found AHA use increased the skin's sensitivity to UV, an effect that faded within a week of stopping [1]. The FDA recommends sunscreen, protective clothing and limiting sun exposure while using AHA products and for a week afterwards [1]. Dr. Aleksandra Brown uses exfoliating acids at bedtime for this reason.
Yes, it is one of the standard options. In a 12 week trial, a 10% lactic acid cream reduced the bumps by 66%, slightly more than 5% salicylic acid [9], and a 2025 review found lactic and glycolic acids were the preferred topicals [10]. The AAD lists lactic acid among the ingredients for it [8]. Dr Dray calls AHAs fantastic for those rough bumps.
It is a classic choice. Lotions with 12% ammonium lactate, a neutralised form of lactic acid, improved moderate to severe dry skin in trials, and kept it better for longer after stopping than 5% lactic acid or a plain emollient [11]. Dr. Aanchal MD suggests a thick cream with urea and lactic acid on hands and feet at night.
It is often the gentler choice. Dr. Vanita Rattan prefers lactic or mandelic acid to glycolic acid for skin of colour. A small study of lactic acid peels in skin type IV found improvement in melasma with no recorded side effects [13], but a 2025 trial found glycolic acid peels worked better for melasma, with similar side effects [14]. Start low and stop at any burning.
The evidence is reassuring but thin. A review notes that lactic acid barely penetrates the skin, and that 2% lactic acid has been used for acne in pregnancy with no reported risk to the baby, though those reports are anecdotal [17]. Nipun Kapur takes the cautious route and avoids it for the nine months of pregnancy. Check with your doctor or midwife.
Think weeks to months. The keratosis pilaris trial ran for 12 weeks [9], the study of 12% lactic acid for three months [7], and the sun damage trial for 22 weeks [6]. The AAD suggests giving a keratosis pilaris plan 4 to 6 weeks before judging it [8]. Steady use with daily sunscreen matters more than a stronger product.
5 experts, 9 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 9 mentions of lactic acid by 5 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 lactic 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 lactic 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.