Unassuming yet ubiquitous in cosmetic formulations, Pentylene Glycol contributes to the stability and sensory comfort of skincare products. Behind this technical name lies an ingredient with multiple functions, often little known to the general public. What is Pentylene Glycol’s actual role in a cream or serum? And is it really a safe ingredient? Learn more below.
What is “Pentylene Glycol” and what is its purpose?
Summary
Published on January 26, 2022, updated on February 23, 2026, by Maylis, Chemical Engineer — 6 min of reading
Themes:
Key points to remember about Pentylene Glycol.
Pentylene glycol is a diol used in cosmetics for its humectant, solvent and preservative functions.
Owing to its water-retention capacity, it contributes to maintaining the hydration of the skin and hair whilst improving formulation stability.
Scientific assessments indicate a generally favourable safety profile, with low toxicity, minimal irritation and a limited risk of sensitisation. However, rare cases of contact allergy have been reported.
As with any cosmetic ingredient, caution is recommended in the event of compromised, damaged or allergy-prone skin.
4 minutes to understand your skin. Our dermatological diagnostic guides you toward the ideal skincare for your specific needs. Simple, quick, personalized.
"Pentylene Glycol": What is it?
Pentylene glycol, also known as pentane-1,2-diol, is an aliphatic diol with the molecular formula C5H12O2. Its chemical structure features two hydroxyl groups on the first and second carbon atoms of the chain, imparting intermediate polarity and good miscibility with numerous hydrophilic and lipophilic compounds. At room temperature, it appears as a colorless, low-viscosity, virtually odorless liquid—physicochemical properties that explain its value in cosmetic formulations.
Chemical structure of pentylene glycol.
Source: PubChem.
Historically, the pentylene glycol used in cosmetics was predominantly obtained via petrochemical synthesis processes derived from mineral oils. However, industry advancements have enabled the development of production pathways from renewable raw materials, obtained through conversion of plant-derived sugars notably from corn or sugarcane. This bio-based origin, now favored in many so-called natural or certified organic formulations, does not alter the compound’s molecular structure but rather addresses environmental concerns and resource sustainability.
At Typology, we use pentylene glycol of vegetable origin, derived from sugar cane.
| Chemical and physical characteristics | Values |
|---|---|
| Chemical formula | C5H12O2 |
| Names | Pentylene glycol, pentane-1,2-diol, 1,2-dihydroxypentane |
| Aspect | Clear and transparent liquid |
| Molar mass | 104.15 g/mol |
| Dosage | Between 0.5% and 10%, typically around 5% |
| Solubility | Soluble in water |
Physicochemical properties of Pentylene Glycol.
Makeup remover
WRINKLES/SKIN DENSITY
What are the cosmetic properties of pentylene glycol?
Pentylene glycol is a versatile compound prized in cosmetic formulations for its technological functions, notably as a solvent and preservative, but also for the benefits it can deliver to skin and hair.
Pentylene glycol is, first and foremost, a humectant, meaning it helps to retain water in the outer layers of the epidermis. The presence of two alcohol (-OH) groups in its structure gives it a particular affinity for water molecules, explaining its hydrophilic nature. By reducing water loss, pentylene glycol contributes to maintaining skin hydration and helps preserve skin suppleness. This hygroscopic capacity can also benefit hair fibers and explains why it is frequently found in treatments designed for dry or damaged hair.
Pentylene glycol also functions as a solvent in formulations. Its compatibility with a wide range of ingredients, whether hydrophilic or partially lipophilic, facilitates the dissolution and homogeneous dispersion of active ingredients. This property contributes to the overall stability of the product and to a more uniform distribution of compounds upon application, without interacting undesirably with other components of the formulation.
Finally, pentylene glycol contributes to microbial contamination control. Though not always used as the sole preservative, it exhibits antimicrobial activity that can strengthen the efficacy of a cosmetic product’s overall preservative system. By limiting bacterial and yeast growth, it thus enhances the microbiological safety of the formulation, ensures its long-term stability, and preserves its performance.
Pentylene glycol: a safe ingredient?
Toxicological evaluation data indicate that pentylene glycol has low toxicity, limited irritant potential, and no significant risk of skin sensitization.
These factors explain its widespread use in cosmetics, including in products intended for daily use. However, despite this favorable safety profile, rare cases of contact dermatitis allergic have been reported, primarily in individuals with sensitive skin or when applied to thin skin areas such as the eyelids. For example, one clinical case describes a 44-year-old woman who developed two episodes of severe facial eczema after using a moisturizing cream containing pentylene glycol. Patch tests confirmed a positive reaction to pentylene glycol at concentrations of 5% and 10%. In contrast, tests carried out on fifteen other volunteers showed no skin reaction, underscoring the individual nature of this type of allergy.
Sources
FRUIJTIER-PÖLLOTH C. Safety assessment on polyethylene glycols (PEGs) and their derivatives as used in cosmetic products. Toxicology (2005).
ANDERSEN F. A. & al. Safety assessment of 1,2-glycols as used in cosmetics. International Journal of Toxicology (2012).
BORGHI A. & al. Pentylene glycol: An emerging cosmetic allergen? Contact Dermatitis (2021).
GILLIET M. & al. Allergic contact dermatitis from pentylene glycol in "hypoallergenic" eye cosmetics. Contact Dermatitis (2022).
