Butylene Glycol
Multifunctional solvent and humectant. Improves cosmetic formula texture and helps active ingredients penetrate the skin.
Evidence by route
Topical application
A formulation aid, not an active ingredient. Safety in cosmetic use confirmed by the CIR expert panel. No standalone therapeutic effect.
- Cosmetic Ingredient Review. Int J Toxicol. 1985;4(5):223-248.
How to read tiers A–F
- DNo data, or very weak or conflicting data
Tolerability and safety
- Irritation potential
- Low
- Allergen risk
- Low
- Pregnancy
- Safe
- Suitable for
- Oily, Dry, Sensitive, Combination, Normal
About this ingredient
Butylene Glycol (1,3-Butanediol) is a synthetic four-carbon glycol, one of the most widespread solvents and humectants in modern cosmetics. Mechanism. On skin it has three roles. Humectant – binds water and holds it in the stratum corneum (weaker than glycerin but non-sticky). Solvent – improves solubility of poorly water-miscible actives (e.g. niacinamide, retinol, azelaic acid). Penetration enhancer – briefly increases stratum corneum permeability, helping actives penetrate. Where applied. Serums, toners, creams, shampoos, makeup primers, micellar waters. Concentration 1–20%. In Spain found in nearly every La Roche-Posay, Avène, ISDIN, Sesderma, Bioderma formula. One of the most common 21st-century cosmetic ingredients. Safety. CIR confirmed safety in 2017. Hypoallergenic, non-comedogenic, non-irritating (unlike propylene glycol, which some patients react to). Topical systemic absorption is low. Contact allergies are isolated – less than 0.1% positive patch tests. Pregnancy and lactation – safe. Used without restriction. Controversies. 'Natural cosmetics' marketing sometimes labels it synthetic and undesirable. At the SCCS, CIR, and AEMPS level the position is stable: safe at cosmetic concentrations. A good choice for patients intolerant to propylene glycol. Functional role. A universal formula aid. No distinct standalone activity as an active – works as humectant, solvent, and penetration enhancer.
Frequently asked questions
Is Butylene Glycol safe during pregnancy?
Butylene Glycol is considered safe during pregnancy at typical cosmetic concentrations. Systemic absorption through the skin is minimal.
What skin types is Butylene Glycol for?
Butylene Glycol suits: oily, dry, sensitive, combination, normal.
What is Butylene Glycol and what does it do in cosmetics?
Multifunctional solvent and humectant.
What's the INCI name for Butylene Glycol?
The INCI name is Butylene Glycol. It may also appear as: 1,3-Butylene Glycol, 1,3-Butanediol, 3-Butanediol.
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