Ammonium lactate: dry scaly skin, how to use it, side effects
Last updated September 7, 2026.
**Ammonium lactate is a topical moisturizer and keratolytic, an alpha hydroxy acid made from lactic acid neutralized with ammonium hydroxide.** The lactic acid loosens the bonds between dead cells on the surface of the skin so thick, flaky scale sheds instead of building up, and it pulls water into the outer skin layer so the area stays softer between applications. The most important safety point is that it goes on intact skin only: applying it to cracked, raw, or freshly shaved skin causes real burning, and it makes treated skin more sensitive to sunlight, so daily sunscreen on exposed areas matters.
What does it treat?
Ammonium lactate is labeled for dry, scaly skin, called xerosis, and for ichthyosis vulgaris, an inherited condition where the skin builds up fish-scale plates most often on the shins, arms, and trunk. It also relieves the itch that comes with those conditions. In everyday primary care it gets used for rough, sandpapery skin on the legs and arms, keratosis pilaris bumps on the upper arms and thighs, thickened skin on the heels and elbows, and winter dryness that plain lotion no longer controls. It comes as a single ingredient product in most cases, sold as Lac-Hydrin and AmLactin among other names, and you will also see it combined with urea, ceramides, or salicylic acid in over-the-counter body creams and foot creams that target the same kind of scaling.
How do you take it?
It comes as a lotion or cream in two strengths: 12 percent, the strength studied in the labeling and sold both by prescription and over the counter, and 5 percent, a lighter over-the-counter version. The usual adult dose is to apply a thin layer to the affected skin twice a day and rub it in thoroughly, which works best right after a shower while the skin is still slightly damp. There is no set milligram ceiling because absorption through intact skin is low, but the label limits where it goes rather than how much: keep it off the face, lips, eyelids, and any mucous membranes, and do not put it on broken, cracked, weeping, or sunburned skin. Food and timing do not matter since nothing is swallowed. If you miss an application, put it on when you remember and go back to your usual twice-daily rhythm, and never double up to catch up. Use sunscreen or clothing on treated areas that see sun. Stop and call a doctor if the skin blisters, peels in sheets, oozes, or turns bright red and painful, if burning lasts more than a few minutes each time, or if the scaling has not improved after about four weeks of steady use.
Side effects to know
- Common: Most people get a brief stinging or burning right after applying, sometimes with mild redness or a pinprick sensation, and this usually fades within a few minutes and eases over the first week or two of use.
- Serious: Stop the product and get medical advice if you develop blistering, skin that peels away in sheets, open sores, spreading swelling, or a rash with weeping and crusting, which can signal an allergic contact dermatitis or a skin infection in the treated area. Get emergency care for hives, facial or throat swelling, or trouble breathing after applying it.
Who should not take it?
Do not use ammonium lactate on broken, chapped to the point of fissuring, inflamed, or sunburned skin, and do not use it if you have had a reaction to lactic acid or alpha hydroxy acid products before. Keep it away from the face, eyes, lips, and genital or anal skin, where it stings badly and can cause lasting irritation. Talk to a doctor first if you have eczema, psoriasis, or an active skin infection in the area, if the dryness is on a diabetic foot with reduced sensation, or if you plan to use it with a prescription retinoid, benzoyl peroxide, salicylic acid, or a chemical peel, since stacking exfoliants multiplies the irritation. It has no meaningful drug interactions with medicines you swallow. FDA labeling for the 12 percent product places it in the older Pregnancy Category B, meaning animal studies showed no harm to the fetus and there are no controlled studies in pregnant women; skin absorption is low, so it is generally considered reasonable in pregnancy, and your obstetric clinician can confirm for your situation. It is not known whether it passes into breast milk, so if you are nursing, avoid applying it to the breast or nipple area where a baby could ingest it. Safety in children under 2 years has not been established. Alcohol has no interaction with this product; you can drink normally.
When is it an emergency?
Real emergencies with this medicine are rare because it stays on the skin, but call 911 for collapse, trouble breathing, swelling of the face, lips, or tongue, or widespread hives after applying it, since that pattern points to anaphylaxis. If a child or adult swallows the lotion or cream, or if it gets into the eyes and rinsing with water for 15 minutes does not settle the pain and blurring, call Poison Control at 1-800-222-1222 right away; swallowing a large amount can cause mouth and throat burning, stomach pain, nausea, and vomiting. Also seek same-day care if treated skin becomes hot, swollen, and tender with spreading redness, yellow crusting, or fever, which suggests an infection rather than a reaction to the product, or if large areas blister or peel away.
What a Pymander AI doctor consult looks like
Illustrative example, not a real member's messages.
Common questions
How much can I use in a day, and can I use it more than twice?
The label dose is a thin layer applied to the affected skin twice a day, rubbed in thoroughly. There is no weight-based or milligram maximum because very little is absorbed through intact skin, so the real limit is irritation, not toxicity. Applying it more than twice daily does not clear scale faster and usually just makes the burning worse. If twice a day is too irritating, drop to once daily or switch to the 5 percent strength, then build back up as your skin adjusts.
Can I drink alcohol while using ammonium lactate?
Yes. Ammonium lactate works on the surface of the skin and does not interact with alcohol. There is no need to time your drinks around applications. Heavy drinking does dehydrate you and can make dry skin look worse overall, so if the scaling is not improving, cutting back may help the underlying dryness.
Is ammonium lactate safe in pregnancy or while breastfeeding?
FDA labeling for the 12 percent product assigns it the older Pregnancy Category B: animal reproduction studies showed no harm to the fetus, and there are no adequate controlled studies in pregnant women. Because absorption through intact skin is minimal, it is generally treated as a reasonable option during pregnancy, and your obstetric clinician can confirm for your case. It is not known whether it passes into breast milk. If you are nursing, do not apply it to the breast or nipple, so a baby cannot swallow any of it during a feed.
Does it matter whether I take it with food, or when I apply it?
Food is irrelevant since nothing is swallowed. Timing does matter for how well it works: applying it within a few minutes of a shower or bath, while the skin is still slightly damp, traps water in the outer layer and gives better softening. Many people do one application in the morning and one at bedtime. Avoid applying it right after shaving the area, because freshly shaved skin has microscopic nicks that will sting hard.
What are the signs of an overdose, and what should I do?
Overdose from normal skin use is not realistic because absorption is so low. The real risk is swallowing it, which can cause burning in the mouth and throat, stomach pain, nausea, and vomiting, or getting it in the eyes, which causes stinging, tearing, and blurred vision. If someone swallows it, call Poison Control at 1-800-222-1222 immediately and do not force vomiting. For eye contact, rinse with cool running water for 15 minutes, then call Poison Control if pain or blurring continues. Call 911 for collapse, trouble breathing, or facial swelling.
Can I use it with a retinoid, salicylic acid, or other exfoliants?
It can be combined, but not carelessly. Ammonium lactate, retinoids like tretinoin or adapalene, salicylic acid, benzoyl peroxide, and chemical peels all thin or loosen the outer skin layer, and stacking them on the same area on the same day frequently produces raw, burning, peeling skin. A common approach is to use them on alternating days or on different body areas, which a clinician can map out for you. Never layer ammonium lactate onto skin that a peel or a strong retinoid has already left red and flaking.
Why does my skin burn in the sun more since starting this?
Alpha hydroxy acids thin the outermost layer of dead cells that normally scatters some ultraviolet light, so treated skin sunburns more easily. This is expected and reversible once you stop. Use a broad spectrum sunscreen of SPF 30 or higher on treated areas that will be exposed, or cover them with clothing. Be especially careful in the first few weeks and if you are using it on your arms, shoulders, or lower legs in summer.