Ammonium Lactate Lotion for Dry Skin, KP, and Psoriasis

Ammonium lactate lotion is a topical moisturizer and mild exfoliant used primarily for stubborn dry skin, rough bumpy patches, and scaling skin conditions. It combines lactic acid (an alpha-hydroxy acid) with ammonium hydroxide, which neutralizes the acid enough to make it gentler on the skin while preserving its ability to hydrate and smooth. Available in both prescription and over-the-counter strengths, it occupies an unusual middle ground between cosmetic moisturizers and medical treatments, and the research behind it is more interesting than you might expect from something that sits on a pharmacy shelf next to hand cream.

How Ammonium Lactate Works on Your Skin

Ammonium lactate pulls double duty. As a humectant, it draws moisture from the environment and deeper skin layers up into the outer skin, increasing hydration. As a keratolytic, it loosens the bonds between dead skin cells on the surface, encouraging them to shed more easily. This combination is what makes it more effective than a standard moisturizer for conditions where the skin is not just dry but also thickened or rough.

In clinical testing, patients using 12% ammonium lactate showed measurable increases in skin hydration (assessed by electrical capacitance), skin surface lipids, and skin elasticity, along with improved barrier function and smoother surface texture.¹ That barrier-function improvement matters because many dry-skin conditions involve a compromised skin barrier that lets moisture escape faster than it should. The lotion does not just add moisture temporarily; it helps the skin hold onto it.

The pH of ammonium lactate lotion typically sits around 4.5 to 5.5, which is close to the skin’s natural acidity. This is lower (more acidic) than many ordinary lotions, and that acidity is part of what drives the exfoliating action. But it also explains why some people feel a sting when they first apply it, especially on cracked or irritated skin.

Xerosis and Severe Dry Skin

The most common reason people reach for ammonium lactate is xerosis, the clinical term for abnormally dry skin. This goes beyond the mild tightness you feel in winter. Xerosis involves visible flaking, roughness, cracking, and sometimes itching that regular lotions do not resolve. It is especially common on the lower legs, feet, and hands, and becomes more prevalent with age as the skin produces less of its own natural moisturizing factors.

A case series evaluating 12% ammonium lactate in patients with severe xerosis found significant improvements in hydration, texture, and reductions in itching, scaling, and roughness over three months.² The lotion’s dual action as humectant and exfoliant helped restore the skin barrier and reduce recurrences, which is often the bigger challenge with chronic dryness. Getting the skin smooth for a week is easy; keeping it that way is where many treatments fall short.

For foot xerosis specifically, ammonium lactate 12% performed comparably to a combination of salicylic acid and urea. Both treatments significantly reduced dryness severity after four weeks, with no meaningful difference between them.³ This is worth knowing if you have tried one approach and found it irritating or unpleasant. You have options that perform similarly.

Keratosis Pilaris

Keratosis pilaris, often called “chicken skin” or “strawberry skin,” produces small rough bumps on the upper arms, thighs, cheeks, or buttocks. It happens when keratin builds up around hair follicles, plugging them. The condition is extremely common, harmless, and mostly a cosmetic concern, but it can be persistent and frustrating to treat.

Ammonium lactate is one of the standard recommendations for keratosis pilaris because its exfoliating action helps clear the keratin plugs while its moisturizing effect softens the surrounding skin. One study evaluated whether adding intense pulsed light (IPL) therapy on top of ammonium lactate would produce better results than ammonium lactate alone. The improvement was not significantly greater with IPL added, as rated by blinded physicians.⁴ That finding actually speaks well of ammonium lactate on its own: it was already doing enough that a more expensive, device-based treatment could not significantly improve on it.

Lactic acid in general appears to be a strong choice for keratosis pilaris. A comparative study found that 10% lactic acid was more effective than salicylic acid for treating the condition and recommended it as the preferred standard treatment.⁵ Since ammonium lactate is essentially a buffered form of lactic acid, this lends support to its use in the same context.

Results with keratosis pilaris tend to be gradual. Expect weeks rather than days before you see meaningful smoothing, and the condition typically returns once you stop using the product. Consistency matters more than intensity here.

Ichthyosis and Inherited Scaling Conditions

Ichthyosis vulgaris is a genetic condition that causes the skin to accumulate dry, fish-scale-like patches because dead cells do not shed normally. It is the most common form of inherited ichthyosis, and while it varies widely in severity, even mild cases can be uncomfortable and cosmetically distressing.

Treatment options for ichthyosis are limited, and management focuses on keeping the skin hydrated and encouraging shedding of the excess scale. A review of ichthyosis vulgaris treatment noted that while urea-based creams are highly effective, ammonium lactate 12% lotion combined with a lipid-based barrier repair cream can help with scaling and dryness.⁶ A separate study specifically testing this combination approach in ichthyosis patients found it effective at four weeks with no adverse effects.⁷

The combination strategy is worth emphasizing. For a condition like ichthyosis, ammonium lactate handles the exfoliating and hydrating components, while a lipid-based cream replenishes the missing barrier lipids that the condition depletes. Neither approach alone does everything the skin needs, but together they address both the shedding problem and the barrier problem.

Psoriasis Maintenance

Ammonium lactate is not a stand-alone psoriasis treatment. You would not slather it on thick plaques and expect them to clear. But it plays a useful supporting role alongside topical corticosteroids, particularly for maintaining improvement after the initial flare has been brought under control.

In a randomized, double-blind, placebo-controlled study, patients with mild-to-moderate plaque psoriasis first used ammonium lactate 12% lotion together with halobetasol propionate ointment (a strong topical steroid) for two weeks. About three-quarters of patients were rated clear or almost clear after that initial combination phase. Then came the more telling part: during a maintenance phase, patients who continued using ammonium lactate daily with weekend-only steroid applications had only about a 10% chance of worsening at six weeks, while the placebo group’s probability of worsening rose to 75%.⁸

This is significant because one of the major concerns with potent topical steroids is skin thinning when used continuously. By pairing daily ammonium lactate with only weekend steroid use, you can stretch out the benefits of the steroid while minimizing its exposure. Ammonium lactate has actually been shown to help prevent steroid-induced skin thinning by preserving the skin’s structural components, so the combination addresses both sides of the problem.⁹

Effects on Skin Thickness and Aging

One of the more intriguing findings about ammonium lactate, and alpha-hydroxy acids in general, is their ability to actually thicken the skin. This sounds counterintuitive for an exfoliant, since exfoliation involves removing surface cells. But the effect happens in deeper layers. Research found that 12% ammonium lactate increased epidermal thickness and boosted the amount of glycosaminoglycans in the dermis, the layer beneath the epidermis.¹⁰ Glycosaminoglycans are the molecules that hold water in your skin and give it that plump, hydrated look.

A study on alpha-hydroxy acids and photoaged skin found roughly a 25% increase in skin thickness, along with a thicker epidermis, more acid mucopolysaccharides in the upper dermis, improved elastic fiber quality, and denser collagen.¹¹ These changes are basically a reversal of what sun damage and aging do to the skin over time: thinning, loss of moisture-holding molecules, and degradation of collagen and elastic fibers.

This is why you sometimes see ammonium lactate mentioned alongside anti-aging products. It is not marketed that way as aggressively as retinoids or vitamin C serums, but the structural skin changes it produces are real and documented at the tissue level. For someone who wants a simpler routine or cannot tolerate retinoids, ammonium lactate offers some of the same architectural benefits, especially for body skin where anti-aging products are less commonly applied.

How It Compares to Urea and Other Options

Urea is probably the closest competitor to ammonium lactate for treating dry, rough, or scaly skin. Both are humectants with keratolytic properties, and both are available over the counter. But they are not interchangeable in every situation.

A clinical comparison of 40% urea cream versus 12% ammonium lactate lotion for xerosis found that urea delivered faster improvement. At two weeks, the urea cream was superior in measures of roughness, fissure reduction, thickness, and dryness.¹² However, a systematic review looking at the same comparison noted that the urea advantage was small and did not persist after both treatments were stopped: during a 14-day follow-up period without any treatment, the difference between groups disappeared.¹³

That detail matters in practice. If your skin is acutely cracked and painful and you need the fastest resolution, high-concentration urea may get you there sooner. But for ongoing management of chronic dryness, the two approaches appear to level out over time. Urea at 40% can also be quite thick and sometimes has a strong odor, which affects whether people actually stick with using it.

When it comes to concentration differences within ammonium lactate itself, more is clearly better up to a point. A double-blind study directly compared 12% ammonium lactate lotion against 5% lactic acid lotion for moderate to severe xerosis. The 12% ammonium lactate was significantly more effective both during the three-week treatment period and during the subsequent three-week regression period after treatment stopped.¹⁴ The fact that the difference persisted even after treatment ended suggests that the higher concentration produces more lasting changes in the skin, not just surface-level softening.

Burning, Stinging, and Cosmetic Drawbacks

The most common complaint with ammonium lactate lotion is that it stings or burns on application, especially when used on skin that is already cracked, inflamed, or freshly shaved. This is not an allergic reaction or a sign that the product is damaging your skin. It is a sensory response to the low pH of the formulation contacting compromised skin. But that distinction is cold comfort when your legs are on fire.

A study comparing lactic acid 10% cream formulated with strontium (a mineral that dampens stinging sensations) against standard ammonium lactate 12% lotion found that patients reported significantly less burning and stinging with the strontium-containing formulation.¹⁵ If stinging has kept you from using ammonium lactate consistently, a strontium-containing lactic acid product may be worth trying as an alternative.

Beyond stinging, cosmetic acceptability can be a barrier. Ammonium lactate lotions tend to have a noticeable odor that some people find unpleasant, and the texture can feel tacky or heavy compared to lightweight cosmetic moisturizers. These sensory factors, including low pH and ingredient odor, can reduce patient acceptance of the product.¹⁶ This is not a trivial concern. A product that works perfectly but sits unused in a cabinet because you hate how it feels or smells is not actually helping you.

Some practical tips for reducing irritation and improving the experience:

Apply to intact skin: Wait a day or two after shaving before using it on the same area. Avoid open cuts or actively inflamed eczema patches.
Start gradually: If you are new to it, try applying once daily or every other day for the first week, then increase to twice daily as your skin adjusts.
Layer strategically: Some people apply a thin layer of ammonium lactate first, let it absorb for a few minutes, then follow with a plain emollient or barrier cream on top. This can reduce the exposed-to-air stinging and lock in more moisture.
Use at night: If the texture or smell bothers you, applying it before bed means you are not wearing it under clothes or noticing the scent all day.

Prescription Versus Over-the-Counter Strengths

Ammonium lactate lotion is available in both prescription and over-the-counter forms. The prescription version is typically 12% ammonium lactate (equivalent to about 12% lactic acid, neutralized). Over-the-counter versions generally come in lower concentrations, though some 12% formulations are now available without a prescription depending on the brand and country.

The 12% strength is the concentration used in virtually all of the clinical research discussed above. If you are buying an over-the-counter ammonium lactate product at a lower percentage, the evidence behind it is thinner. That does not mean a 5% or 8% product is useless, but the published studies showing benefits for keratosis pilaris, ichthyosis, psoriasis maintenance, and severe xerosis were conducted at the 12% level. As the comparison study noted, 12% ammonium lactate significantly outperformed 5% lactic acid for moderate to severe dryness.¹⁷

If your dryness is mild and seasonal, a lower concentration or even a simple lactic-acid-containing moisturizer may be sufficient. But if you are dealing with a chronic condition like keratosis pilaris or ichthyosis, or severe xerosis that has not responded to regular moisturizers, the 12% strength is what the evidence supports. Talk to a pharmacist if you are unsure which strength is available to you without a prescription in your area.

Who Should Avoid It

Ammonium lactate is generally well tolerated, but there are situations where it is not the right choice. Because of its acidic pH, it should not be applied to sunburned skin, open wounds, or skin with active dermatitis flares. The stinging on compromised skin is not just uncomfortable; applying an acid to raw, inflamed tissue can potentially worsen irritation.

People with very sensitive skin or conditions like rosacea may find even intact-skin application too irritating. If you have had reactions to other alpha-hydroxy acid products (glycolic acid peels, lactic acid serums), ammonium lactate may trigger similar sensitivity, though its buffered formulation is gentler than pure lactic acid at the same concentration.

It is also worth noting that alpha-hydroxy acids increase sun sensitivity. If you are using ammonium lactate on sun-exposed areas like your arms or legs in summer, using sunscreen on those areas becomes more important than usual. This is less of a concern when the lotion is used mainly on covered areas like the trunk or lower legs, or when applied only at night.

For children, ammonium lactate is sometimes used for keratosis pilaris or ichthyosis, but the stinging can be particularly poorly tolerated by younger kids. Pediatric use generally warrants guidance from a dermatologist rather than self-directed over-the-counter experimentation. Some parents find that applying the lotion mixed with a plain emollient in a 1:1 ratio reduces the sting enough to make it tolerable, though this also dilutes the active concentration.

Unusual Uses in Dermatology

Beyond its common indications, ammonium lactate has occasionally been tried for less typical conditions with mixed results. One case report described its use for nevus comedonicus, a rare condition involving clustered dilated pores resembling blackheads. Previous treatments including oral isotretinoin, topical tretinoin, salicylic acid, and other acid creams had been ineffective or minimally effective before ammonium lactate was tried.¹⁸ Case reports are the weakest form of evidence, but they illustrate how dermatologists sometimes reach for ammonium lactate when other keratolytic agents have failed, leveraging its unique combination of exfoliation and hydration.

The steroid-atrophy-prevention property is another area that deserves more attention than it gets. Many people use topical steroids for eczema, psoriasis, or other inflammatory conditions and worry about long-term skin thinning. The finding that ammonium lactate increases epidermal thickness and dermal glycosaminoglycans suggests it may serve as a useful adjunct for anyone on chronic topical steroid therapy, not just psoriasis patients.¹⁹ This application is underexplored in formal trials but makes mechanistic sense given what the lotion does at the tissue level.