What Is 2,3-Butanediol?
2,3-Butanediol, sometimes called 2,3-butylene glycol, is a clear, slightly viscous liquid that belongs to the family of diols, which are ingredients with two alcohol groups. It can be sourced through the fermentation of sugars using certain bacteria or produced synthetically from petroleum-derived feedstocks. Early on it was investigated for industrial uses like antifreeze, but skin care chemists soon noticed its gentle feel, water-binding skill and faintly sweet scent, which opened the door to cosmetic use in the late 20th century.
Today most cosmetic-grade 2,3-butanediol comes from controlled fermentation of renewable plant sugars, followed by purification to remove odors and impurities. This process results in a high-purity ingredient that blends smoothly with water-based formulas. You will spot it in many leave-on and rinse-off products such as moisturizers, sheet masks, gel creams, anti-aging serums, hydrating toners and setting sprays, as well as in some fragrances and makeup bases where it helps keep textures smooth and flexible.
2,3-Butanediol’s Cosmetic Benefits/Uses
Here is how 2,3-butanediol supports the performance of beauty products:
- Fragrance – carries and subtly enhances scent blends, helping fragrances last longer on the skin
- Humectant – draws water from the environment into the upper layers of skin, boosting surface hydration and giving a fresh, dewy look
- Skin Conditioning – leaves a soft, smooth feel, improving the overall sensory experience of creams and gels
- Solvent – dissolves other active ingredients or aromatic compounds so they spread evenly throughout the formula
Who Can Use 2,3-Butanediol
Because it is a gentle, water-loving molecule, 2,3-butanediol suits almost every skin type. Dry and dehydrated skin benefit from its humectant action, oily or combination skin enjoy lightweight hydration that will not feel greasy, and even sensitive skin usually tolerates it thanks to its low irritation potential. Only individuals with a known glycol allergy or an exceptionally reactive barrier may need to avoid it.
The ingredient is produced through fermentation of plant-derived sugars and involves no animal inputs, so it is considered suitable for vegans and vegetarians. Of course, cruelty-free status depends on the finished brand’s testing policies.
Pregnant or breastfeeding women are not known to face special risks when using products containing 2,3-butanediol. It is regarded as a low-hazard cosmetic solvent and humectant, yet this is not medical advice. Anyone who is expecting or nursing should still run all skincare choices past a healthcare professional, just to be safe.
2,3-butanediol does not make skin more sensitive to sunlight and can be used morning or night without raising the risk of sunburn. It remains stable across a wide pH range and plays well with most other cosmetic ingredients, so there are no notable formulation conflicts to flag.
Potential Side Effects/Adverse Reactions
Everyone’s skin is unique, so responses to topical 2,3-butanediol can vary. The points below list potential side effects that have been observed in a small minority of users. When the ingredient is properly formulated and used as directed most people will not experience these issues.
- Mild transient stinging or burning
- Redness or warmth in the application area
- Dry or tight feel if used in a very high concentration without added occlusives
- Allergic contact dermatitis in individuals sensitized to glycols
- Eye irritation if the product accidentally gets into the eyes
- Enhanced penetration of accompanying actives which could indirectly trigger irritation from those actives
If any discomfort, rash or prolonged irritation develops stop using the product and consult a qualified medical professional.
Comedogenic Rating
Rating: 0/5 (non-comedogenic)
2,3-Butanediol is a small, water-soluble molecule that does not form an oily film on the skin and is easily rinsed away. It lacks the heavy, waxy structure that typically clogs pores, which is why formulators consider it non-comedogenic. This makes it an appropriate choice for people prone to acne or breakouts.
No reports link this ingredient to increased sebum production or follicular blockage, even in high-humidity climates. Its ability to pull in moisture can actually help maintain a balanced skin surface, limiting the dry-then-rebound-oil cycle that sometimes contributes to congestion.
Summary
2,3-Butanediol works as a humectant, skin conditioner, solvent and light fragrance helper. It binds water to keep skin comfortably hydrated, smooths texture for a silky afterfeel, dissolves other actives so they spread evenly, and subtly boosts scent longevity.
While it is not a headline making superstar, this quiet multitasker appears in a wide range of modern toners, serums, masks and setting sprays because it improves slip and hydration without heaviness.
Current safety data place it in the low-risk category for topical use, with irritation or allergy being rare. As with any new skincare ingredient it is wise to do a quick patch test before full application to confirm personal tolerance.