Lactic Acid
Lactic Acid (an alpha hydroxy acid, AHA)
An acid that gently exfoliates the outer layer of skin.
Lactic acid dissolves dead skin cells from the surface, helping skin look smoother and feel softer over time.
In three sentences
Lactic acid is an alpha hydroxy acid that works by dissolving dead skin cells on the outer surface. It helps skin feel smoother and can improve texture when used regularly. You must wear sunscreen daily because it may increase UV sensitivity.
What it does
It works like a gentle chemical eraser that buffs away the dull outer layer of skin.
Lactic acid is an alpha hydroxy acid (AHA) that breaks down the bonds holding dead skin cells to the surface, allowing them to shed. This process is called exfoliation. As dead cells are removed, skin typically feels smoother and looks brighter.
Studies report that glycolic acid, another AHA, increases UV sensitivity, and lactic acid is also an AHA. Daily sunscreen is essential when using this ingredient, even on cloudy days. If you are taking isotretinoin, studies report that superficial chemical peels with AHA are generally tolerated during treatment, though you should check with your dermatologist before proceeding.
Typical concentration
Over-the-counter products usually use 5 to 10%. The US Cosmetic Ingredient Review advises 10% or less at pH 3.5 or higher.
Who should be careful
Pregnant people should be cautious with AHA products. No source was found on lactic acid specifically in pregnancy, but a review noted that some skin-care ingredients have high systemic absorption during pregnancy. Check with your obstetrician before using. Anyone taking isotretinoin should consult their dermatologist before using AHA peels. If you have very sensitive skin or a history of irritation, start slowly and use sunscreen daily.
Pairing
Pairs well with
- Niacinamide (Vitamin B3)
- Glycerin (a humectant)
- Sodium Hyaluronate (Hyaluronic Acid)
Use with care alongside
- Salicylic Acid (a beta hydroxy acid, BHA)
- Retinol
- Retinaldehyde
Found in
- Zero Pore Pad 2.0 (70ea)MEDICUBE
FAQ
- Does lactic acid hurt or sting?
- Lactic acid can cause mild tingling or warmth on the skin, especially at first. If you feel significant stinging or burning, rinse it off and try a lower concentration. Your skin may adjust as you use it over time.
- Can I use lactic acid every day?
- Most people can use lactic acid daily, but start with a few times per week to see how your skin responds. Daily use is safe for many, but sensitive skin may do better with two or three times weekly.
- Does lactic acid make my skin sun-sensitive?
- Studies report that glycolic acid, another AHA, increases UV sensitivity, and lactic acid is also an AHA. Apply sunscreen every day when using lactic acid products, even indoors or on cloudy days.
Regulatory status
| Country | Authority | Status |
|---|---|---|
| Korea | MFDS | Allowed |
| United States | FDA | Allowed |
| Japan | MHLW | Allowed |
Status in one country says nothing about another.
Sources
- Studies report that glycolic acid, another AHA, increases UV sensitivity.Dual Effects of Alpha-Hydroxy Acids on the Skin (PubMed, 2018, human)
- Studies report that superficial chemical peels with AHA are generally tolerated during treatment.ASDS Guidelines Task Force: Consensus Recommendations Regarding the Safety of Lasers, Dermabrasion, Chemical Peels, Energy Devices, and Skin Surgery During and After Isotretinoin Use (PubMed, 2017, human)