LACTIC ACID
Humectant
Moderate
CAS Number: 50-21-5
About LACTIC ACID
A gentle exfoliating acid (AHA) that smooths skin texture and boosts hydration — effective but can irritate if overused, and definitely needs sunscreen.
Detailed Analysis
Lactic acid (C₃H₆O₃, CAS 50-21-5) is an alpha-hydroxy acid naturally produced in the body and found in fermented foods. In cosmetics, it functions as an exfoliant (promotes cell turnover), pH buffer, and humectant. CIR Expert Panel deems safe ≤10% at pH ≥3.5 with sunscreen warnings. Below 10%, primarily moisturizing; 10-30%, effective exfoliation; >30%, professional peels only. GHS classification (H314, H315, H318) reflects concentrated form. Milder than glycolic acid, making it suitable for sensitive skin. Increases photosensitivity — sunscreen essential.
What It Does
Skin Benefits
- ✓ Gentle chemical exfoliation — promotes cell turnover
- ✓ Improves skin texture and tone
- ✓ Humectant properties — attracts moisture
- ✓ Reduces appearance of fine lines and hyperpigmentation
- ✓ Milder than glycolic acid — suitable for sensitive skin beginners
Known Concerns
- ⚠ Increases sun sensitivity — sunscreen required
- ⚠ Can cause irritation, redness, burning at higher concentrations
- ⚠ Over-exfoliation can damage skin barrier
- ⚠ Avoid combining with retinoids or other strong exfoliants
- ⚠ Eye irritant (concentrated form)
Safety Score
Moderate
Based on EU regulatory data, published safety research, and ingredient function analysis.
References
EU CosIng Database
European Commission cosmetic ingredient registry
PubChem
National Library of Medicine compound data
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Download LuxSenseThis information is for educational purposes only and does not constitute medical advice. Always consult a healthcare professional for skin concerns or allergies.