What Is Undecylpentadecanol?
Undecylpentadecanol is a long chain fatty alcohol known in chemistry circles as isohexacosyl alcohol. It is usually made from natural fatty acids sourced from plants such as coconut or palm oil, then refined through hydrogenation to reach its final stable form. Cosmetic chemists began experimenting with this ingredient in the late 1990s while searching for alternatives to heavier waxes that could soften skin without feeling greasy. Its pleasant slip and strong skin affinity soon earned it a spot in moisturizers, facial masks, anti aging creams, body lotions and leave-on treatments.
To produce commercial grade undecylpentadecanol, manufacturers first isolate the right length fatty acids, convert them to fatty alcohols in a high pressure reactor, then purify the product through distillation. The result is a white, wax-like solid that melts on contact with skin. Because it is non volatile and odor free it works well in both water-in-oil and oil-in-water emulsions, giving formulators plenty of flexibility.
Undecylpentadecanol’s Cosmetic Benefits/Uses
This ingredient lends two key benefits to personal care formulas
- Skin conditioning: Forms a soft, breathable film on the surface of skin that helps lock in moisture, smooth rough patches and leave skin feeling supple
- Emollient: Fills tiny gaps between skin cells, reducing flakiness and improving overall texture while adding a silky touch to creams and lotions
Who Can Use Undecylpentadecanol
Because it is lightweight yet deeply softening, undecylpentadecanol is generally well tolerated by all skin types. Dry and mature skin tend to benefit most thanks to its strong moisture sealing ability, while normal and combination skin appreciate the smooth non greasy finish. Oily or acne-prone users can also use it because it has a low tendency to clog pores, though extremely blemish-prone individuals might prefer to patch test first.
The ingredient is typically derived from coconut or palm sources so it is suitable for vegans and vegetarians provided the finished product does not contain other animal derived materials.
No data suggest that topical undecylpentadecanol poses specific risks during pregnancy or breastfeeding. Still, this is not medical advice and anyone who is pregnant or nursing should ask a healthcare professional before introducing new skincare products.
Undecylpentadecanol does not increase photosensitivity so there is no special need for extra sun precautions beyond daily sunscreen use. It is also fragrance free and non volatile, which makes it a good option for sensitive noses.
Potential Side Effects/Adverse Reactions
Reactions to topical undecylpentadecanol vary from person to person. The issues listed below are uncommon and most people will not experience them when the ingredient is used at normal cosmetic levels.
- Mild redness or irritation in very sensitive skin
- Temporary stinging if applied to broken or freshly exfoliated skin
- Rare allergic contact dermatitis due to individual sensitivity
- Possible pore congestion in users extremely prone to comedones
If any of these effects occur discontinue use and consult a healthcare professional for guidance.
Comedogenic Rating
Rating: 1/5. Undecylpentadecanol is a long chain fatty alcohol with a relatively large molecular size, so it tends to sit on the surface and create a breathable film rather than seeping deeply into pores where clogs form. In routine concentrations used in creams and lotions it rarely triggers blackheads or whiteheads, making it a low risk choice for breakout-prone skin. Those with very reactive or severely congested skin can still monitor how their skin responds, but for most users it remains a gentle option.
Because it provides slip without heavy, occlusive waxes, formulators sometimes pick it specifically to keep rich products feeling lighter while maintaining low comedogenicity.
Summary
Undecylpentadecanol serves mainly as a skin conditioning agent and emollient. By melting at body temperature and filling gaps between skin cells it smooths texture, softens dry patches and reinforces the skin’s natural moisture barrier. Its silky finish improves spreadability so lotions and creams glide on easily without a greasy afterfeel.
Although not as famous as ingredients like squalane or shea butter, it appears in a growing number of moisturizers and masks where formulators want a lightweight waxy touch. Its plant-derived origin, lack of scent and low irritation profile contribute to its quiet but steady popularity in clean and sensitive skin lines.
Safety data show it is well tolerated with minimal risk of irritation or clogged pores. Still, everyone’s skin is unique so it is always wise to patch test any new product containing undecylpentadecanol before full application.