Ammonium Lactate Lotion: What It Does for Rough, Dry and Crepey Body Skin

Ammonium lactate lotion has an unglamorous reputation. It comes in plain bottles, makes no promises about glow, and was already being tested in dermatology trials in the 1980s. Yet it remains one of the few body moisturizers backed by head-to-head trials, and dermatologists still reach for it when legs look like cracked paving and arms feel like sandpaper.

The reason is the active ingredient. Ammonium lactate is lactic acid, an alpha hydroxy acid, that has been partly neutralized with ammonium hydroxide. That buffering makes a 12% lactic acid lotion far gentler than straight acid at the same strength, while keeping two useful jobs: pulling water into the skin and loosening the rough, dead cells that build up on dry legs and arms.

What 12% ammonium lactate does

Lactic acid works on two levels. At the surface, it weakens the bonds between dead cells so that scaly, compacted skin sheds more evenly, and it acts as a humectant that helps the outer layer hold water [1]. That combination is why a 12% lotion feels different from a plain moisturizer: it does not just coat rough skin, it helps remove it.

The more surprising finding is what happens deeper down. In volunteers who applied 12% ammonium lactate to their forearms for three to four weeks, biopsies showed a thicker epidermis and more glycosaminoglycans, the water-binding molecules that give the dermis its cushion. The lotion even limited the thinning caused by a very potent steroid cream applied to the same skin [2].

Your thin, crepey forearm skin can get measurably thicker within 4 weeks from a lotion, something most body moisturizers have never been shown to do.

What the trials found

The strongest evidence comes from studies in moderate to severe xerosis, the medical term for very dry, scaly skin:

Your thin, crepey forearm skin can get measurably thicker within 4 weeks from a lotion, something most body moisturizers have never been shown to do.

• Against a lower-strength acid. In a double-blind trial, 12% ammonium lactate was significantly more effective than 5% lactic acid lotion after three weeks of twice-daily use, and the advantage persisted through a further three weeks without treatment [3].
• Against a petrolatum cream. In a two-center double-blind study, the 12% lotion also outperformed a petrolatum-based therapeutic cream, both during treatment and afterward [4].
• Against high-strength urea. In a smaller bilateral comparison, 40% urea cream worked faster than 12% ammonium lactate, beating it on roughness, fissures, thickness and dryness at day 14 [5].

The pattern is clear. Ammonium lactate outperforms a petrolatum cream and a weaker acid lotion, but very high-strength urea can soften thick, cracked skin faster. Our guide to urea for skin explains when urea is the better choice, especially for heels and severely thickened patches.

The anti-aging angle

Strength matters for aging skin. In a three-month study comparing 5% and 12% lactic acid, both improved smoothness and the look of lines, but only the 12% strength increased firmness and thickness in the dermis as well as the epidermis [6].

Your crepey arms and shins are usually a mix of dryness and thinning, and a 12% lactic acid lotion is one of the few products tested against both.

That makes ammonium lactate a useful first step for crepey skin on the arms and legs. It smooths the dry, papery surface quickly and supports thickness over weeks. It is not, however, a dedicated collagen builder, and the trials measured thickness rather than lasting firmness.

Your crepey arms and shins are usually a mix of dryness and thinning, and a 12% lactic acid lotion is one of the few products tested against both.

Who it suits, and when to be careful

Ammonium lactate tends to suit:

• Rough, dry legs and arms that stay flaky even with daily moisturizer.
• Bumpy skin on the upper arms and thighs. Alpha hydroxy acids, beta hydroxy acids and urea are reasonable first-line options for keratosis pilaris, though the trials are small and short [7].
• Thin, crepey body skin that also feels dry.

Be careful in these situations:

• Cracked, broken or freshly shaved skin. Acids can sting and burn on damaged skin [1]. Let small cuts heal, and avoid applying straight after shaving.
• The face. Ammonium lactate is formulated as a body lotion, so for your face choose a dedicated product such as a lactic acid serum or cream designed for thinner facial skin and easier to layer under sunscreen and makeup.
• Sun exposure. Alpha hydroxy acids increase the skin’s sensitivity to UV. In a controlled study, daily 10% glycolic acid raised sunburn cell formation and lowered the UV dose needed to cause redness, an effect that reversed within a week of stopping [8]. Use sunscreen on any treated skin that sees daylight.

How to use it

Apply your ammonium lactate lotion once or twice a day to clean, dry skin, massaging it in until absorbed. A mild tingle for the first few uses is common; persistent burning or redness is a signal to cut back to once a day or every other day. The trials measured clear improvement within two to three weeks, and the benefit outlasted treatment by several more [3].

On very dry, cracked areas, start with a plain bland moisturizer for a few days to calm the skin, then introduce the acid lotion. And always wash your hands after applying it, so you do not transfer it to your eyes or face.

Where lactic acid stops, and retinol starts

Ammonium lactate is excellent at fixing the surface and modestly thickening thin skin. Retinoids go further, changing how skin cells behave and switching collagen production back on. In a randomized, vehicle-controlled trial in adults with an average age of 87, a 0.4% retinol lotion applied to one arm for 24 weeks significantly improved fine wrinkling and increased new collagen and glycosaminoglycans compared with the arm treated with a plain vehicle lotion [9]. Our guide to retinol body lotions covers how to choose one for crepey arms and legs.

The obstacle is irritation. Conventional retinol already causes redness and peeling in many people, and layering it with an acid lotion on the same skin makes that more likely.

That is where Nanoretinol fits. It delivers 0.2% stabilized retinol inside biomimetic lipid nanoparticles that the skin recognizes as its own, so it reaches skin cells without breaking down the barrier the way conventional formulations can. In North Biomedical’s study summary, Nanoretinol was 232% more effective in collagen recovery and 73% more effective in elastin recovery than conventional retinol, and in 56 days of use it increased skin firmness by 61% [10]. Its light, water-based gel absorbs completely and leaves a smooth matte finish.

A simple routine: ammonium lactate on dry legs and arms in the morning, followed by sunscreen on exposed areas, and Nanoretinol at night on crepey patches. The lotion smooths the surface; the retinol rebuilds what lies beneath.

References

1. Tang SC, Yang JH. “Dual Effects of Alpha-Hydroxy Acids on the Skin.” Molecules. 2018;23(4):863. doi:10.3390/molecules23040863
2. Lavker RM, Kaidbey K, Leyden JJ. “Effects of topical ammonium lactate on cutaneous atrophy from a potent topical corticosteroid.” Journal of the American Academy of Dermatology. 1992;26(4):535-544. PubMed:1597538
3. Rogers RS 3rd, Callen J, Wehr R, Krochmal L. “Comparative efficacy of 12% ammonium lactate lotion and 5% lactic acid lotion in the treatment of moderate to severe xerosis.” Journal of the American Academy of Dermatology. 1989;21(4 Pt 1):714-716. PubMed:2808786
4. Wehr R, Krochmal L, Bagatell F, Ragsdale W. “A controlled two-center study of lactate 12 percent lotion and a petrolatum-based creme in patients with xerosis.” Cutis. 1986;37(3):205-209. PubMed:3514154
5. Ademola J, Frazier C, Kim SJ, Theaux C, Saudez X. “Clinical evaluation of 40% urea and 12% ammonium lactate in the treatment of xerosis.” American Journal of Clinical Dermatology. 2002;3(3):217-222. doi:10.2165/00128071-200203030-00007
6. Smith WP. “Epidermal and dermal effects of topical lactic acid.” Journal of the American Academy of Dermatology. 1996;35(3 Pt 1):388-391. PubMed:8784274
7. Dampa E. “The Effectiveness of Topical Keratolytics (Alpha Hydroxy Acids/Beta Hydroxy Acids/Urea) in Treating Keratosis Pilaris: A Review of the Literature.” Cureus. 2025;17(12):e100507. doi:10.7759/cureus.100507
8. Kaidbey K, Sutherland B, Bennett P, et al. “Topical glycolic acid enhances photodamage by ultraviolet light.” Photodermatology, Photoimmunology & Photomedicine. 2003;19(1):21-27. doi:10.1034/j.1600-0781.2003.00013.x
9. Kafi R, Kwak HS, Schumacher WE, et al. “Improvement of naturally aged skin with vitamin A (retinol).” Archives of Dermatology. 2007;143(5):606-612. doi:10.1001/archderm.143.5.606
10. North Biomedical LLC. “Nanoretinol vs. Conventional Retinol: Efficacy in Collagen and Elastin Recovery.” Clinical Study Summary, 2024. Study summary