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Skincare Ingredient

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Lactic Acid

In Skincare: Is Lactic Acid Safe? Comedogenic Rating & Side Effects

Comedogenicity (pore clogging)
1/5 — Very low risk
Safety (overall safety)
2/5 — Low risk
Irritancy (skin irritation)
3/5 — Moderate risk

Quick Insights

At a glance

  • 01

    Lactic acid gently exfoliates the skin's surface to reveal a smoother complexion.

  • 02

    As an alpha hydroxy acid (AHA), lactic acid possesses hydrating properties that can help improve skin moisture.

  • 03

    Lactic acid, an AHA found in sour milk and sugarcane, may help strengthen the skin's natural barrier.

  • 04

    Lactic acid can positively influence the skin’s microbiome, which is a community of microorganisms living on the skin.

Key Benefits

What Lactic Acid does for your skin

3 benefits
Anti-Aging
Evens Skin Tone
Hydration

Overview

Ingredient Profile

Lactic acid is an alpha hydroxy acid (AHA) that gently exfoliates the skin's surface by dissolving the bonds between dead skin cells, promoting natural shedding. It also provides hydration as it is a component of the skin's natural moisturizing factor and can strengthen the skin barrier by encouraging ceramide production. Furthermore, lactic acid may help improve uneven skin tone and positively influence the skin's microbiome to support a healthy defense against signs of stress.
Classifications
Exfoliant
Humectant
pH Adjuster/Stabilizer

Data & Research

Scientific Facts

Lactic acid is an alpha hydroxy acid (AHA). It can be naturally derived from sources like milk or synthetically produced. Lactic acid has a long history of use in skincare, with evidence suggesting its utilization by Cleopatra. Glycolic acid is a related AHA, typically produced from sugar cane and widely used in cosmetic formulations.

Common Uses

Formulation in Lactic Acid

Lactic acid and its salts/esters are utilized in cosmetics and personal care products for their exfoliating properties, contributing to improvements in skin texture and appearance. They are incorporated into formulations such as moisturizers, cleansing products, makeup, hair care products and colorants.

Role of Lactic Acid

Active Cosmetic Mechanisms

BUFFERING

pH Stabilizer

Maintains stable pH levels in products

SCIENTIFIC ANALYSIS

// Evidence: Buffering systems resist pH changes through weak acid-conjugate base pairs (citric acid/sodium citrate, lactic acid/sodium lactate, phosphate salts) that operate within specific pH ranges based on their pKa values. The mechanism follows the Henderson-Hasselbalch equation, with buffer components neutralizing added H⁺ or OH⁻ ions. Proper buffering prevents pH drift and maintains efficacy.

HUMECTANT

Moisture Magnet

Attracts and retains moisture in skin and hair

SCIENTIFIC ANALYSIS

// Evidence: Humectant ingredients draw water from the environment and deeper skin layers through hygroscopic properties. Common humectants include glycerin, propylene glycol, hyaluronic acid, urea, and alpha-hydroxy acids. These contain multiple hydroxyl groups or other hydrophilic functional groups that form hydrogen bonds with water molecules. Mechanism involves attracting water to the stratum corneum, reducing transepidermal water loss, and increasing skin hydration.

SKIN CONDITIONING

Skin Enhancer

Maintains skin in good condition and improves its feel

SCIENTIFIC ANALYSIS

// Evidence: Skin conditioning ingredients enhance appearance, texture, and health of skin through various mechanisms. This broad category encompasses emollients, humectants, occlusives, and other agents that improve skin feel, appearance, and function. May work by moisturizing, smoothing, softening, or protecting skin. Effects include improved tactile properties, enhanced barrier function, and better overall skin condition.

Products

containing Lactic Acid

7714 formulations
Denní Krém S Amarantovým Olejem A Hedvábím
Denní Krém S Amarantovým Olejem A Hedvábím
Ryor · moisturizer
Olive Real Cleansing Foam
Olive Real Cleansing Foam
innisfree · cleanser
Výživný Krém S Přírodními Oleji
Výživný Krém S Přírodními Oleji
Ryor · moisturizer

References

Scientific sources

[1]

International Journal of Cosmetic Science, April 2020, pages 116-126

[2]

International Journal of Dermatology, March 2019, ePublication

[3]

Clinical, Cosmetic, and Investigational Dermatology, October 2018, pages 491-497

[4]

International Journal of Dermatology, September 2018, ePublication

[5]

Molecules, April 2018, ePublication

[6]

Journal of the American Dental Association, April 2016, pages 255-263

[7]

Cutis, January 2016, pages E9-E11

[8]

Clinical, Cosmetic, and Investigational Dermatology, November 2010, pages 135-142

[9]

The Journal of Dermatology, January 2006, pages 16-22

Semantic Analysis

Similar Ingredients

Ingredients with similar chemical profiles and skincare properties.

Frequently Asked Questions

Lactic Acid — common questions

What is Lactic Acid in skincare?

Lactic acid is a naturally occurring organic alpha hydroxy acid (AHA). Salts and esters of lactic acid, including Ammonium Lactate, Calcium Lactate, Potassium Lactate, Sodium Lactate, and TEA-Lactate, are also frequently used in cosmetics. These ingredients can be derived from both natural sources (primarily milk) and are also produced synthetically. They are commonly found in a variety of products such as moisturizers, cleansers, makeup, shampoos, hair dyes and colorants, and other personal car

What does Lactic Acid do? / Functions of Lactic Acid?

Common functions: BUFFERING, HUMECTANT, SKIN CONDITIONING.

What is the comedogenic rating of Lactic Acid? / Is Lactic Acid comedogenic?
1 1/5 — Very low risk

Lactic Acid has a comedogenic rating of 1 out of 5. A rating of 1 means it is unlikely to clog pores.

Does it clog pores?
Unlikely to Clog Pores

Lactic Acid is unlikely to clog pores (rating 1/5).

Is Lactic Acid safe for skin?
2 2/5 — Low risk

Lactic Acid has a safety rating of 2 out of 5. A rating of 2 means it is generally considered safe for most skin types.

Is Lactic Acid good for sensitive skin?
3 3/5 — Moderate risk

Lactic Acid has an irritancy rating of 3 out of 5. A rating of 3 means it may cause mild irritation for some.

What are the side effects of Lactic Acid in skincare?

Potential side effects include skin irritation (irritancy rating 3/5).

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