What Is Tetradecyl/Hexadecyl C18-20 Hydroxyalkyl Acid?
Tetradecyl/Hexadecyl C18-20 Hydroxyalkyl Acid is the cosmetic name for 2-hexadecyl-3-hydroxyicosanoic acid, a long-chain fatty acid with a single hydroxyl group along the chain. It is usually sourced from plant-derived fatty acids that are further refined in the lab, though some manufacturers may start with renewable oils from seeds like palm or rapeseed. Chemists convert these raw fatty acids through controlled oxidation and hydroxy-functionalization, then blend the resulting C18 to C20 chains with smaller tetradecyl and hexadecyl groups to get a stable mixture that works well on skin.
The ingredient first appeared in specialty skin care in the early 2000s when formulators sought out bio-derived lipids to reinforce the skin barrier without the heaviness of mineral oil. Over time its protective qualities made it a regular feature in moisturizers aimed at sensitive or dry skin.
Today you will most often spot Tetradecyl/Hexadecyl C18-20 Hydroxyalkyl Acid in hydrating face creams, overnight masks, barrier-repair serums, hand lotions and after-sun balms. It is prized for being compatible with both rich and lighter textures, so you may also see it in anti-aging emulsions and targeted spot treatments that need to soothe while delivering actives.
Tetradecyl/Hexadecyl C18-20 Hydroxyalkyl Acid’s Cosmetic Benefits/Uses
This ingredient is best known for one main job in skin care.
Skin protecting: The fatty acid structure forms a soft, flexible film on the surface of the skin that helps lock in moisture, fend off environmental irritants and reduce visible dryness. By reinforcing the skin’s own lipid layer it can make formulations feel more comforting, calm areas of flakiness and support a healthy looking barrier, which in turn can enhance the performance of other hydrating or anti-aging ingredients in the same product.
Who Can Use Tetradecyl/Hexadecyl C18-20 Hydroxyalkyl Acid
This fatty acid blend is generally well tolerated by most skin types, including dry, normal, combination and even mild sensitive skin, because it mimics the skin’s own lipids and does not contain common irritants. Oily and acne-prone users can still benefit from its barrier support but may prefer it in lightweight formulas since richer creams could feel heavy if applied too generously.
The ingredient is sourced from plant oils and no animal-derived materials are involved in its manufacture, so it is suitable for vegans and vegetarians.
No data suggest that topical use poses a risk to pregnant or breastfeeding women when used in standard cosmetic concentrations. This is not medical advice, and anyone who is pregnant or nursing should show their skin care routine to a qualified healthcare provider to be safe.
Tetradecyl/Hexadecyl C18-20 Hydroxyalkyl Acid is not known to increase photosensitivity, so it does not make the skin more prone to sunburn. Standard sun protection practices are still recommended for overall skin health.
Potential Side Effects/Adverse Reactions
Side effects from topical use of Tetradecyl/Hexadecyl C18-20 Hydroxyalkyl Acid can vary between individuals. The points below outline potential reactions, though most people will not experience them when the ingredient is formulated and used properly.
- Mild redness or warmth
- Temporary itching on very sensitive skin
- Clogged pores if layered heavily on oily or acne-prone areas
- Allergic contact dermatitis in rare cases for those with specific lipid sensitivities
If any of these reactions occur, discontinue use and consult a healthcare professional for further guidance.
Comedogenic Rating
Rating: 2 out of 5
Tetradecyl/Hexadecyl C18-20 Hydroxyalkyl Acid is a mid-length fatty acid blend that sits lightly on the skin compared with heavier oils, yet it still has some occlusive properties. This places it at the lower end of the comedogenic scale, though not completely risk free for very oily or congested complexions. Most users will not notice clogged pores when the ingredient is used at typical low percentages, but overapplication or pairing it with other rich emollients can increase the likelihood.
Suitable for acne-prone skin when found in lightweight or gel-cream formulas, but those who break out easily may want to keep an eye on how their skin responds.
Formulation context matters. When combined with non-comedogenic humectants or used in water-based emulsions the risk of pore blockage drops further, while thicker balms that layer multiple fatty ingredients could push the rating slightly higher in practice.
Summary
Tetradecyl/Hexadecyl C18-20 Hydroxyalkyl Acid is valued for its skin-protecting talent. By forming a soft lipid film that mimics the skin’s own barrier it locks in moisture, shields against external irritants and calms patches of dryness without feeling overly greasy. Its compatibility with a wide range of textures lets formulators slip it into everything from feather-light serums to rich night creams.
Although not a household name, the ingredient has carved out a niche in barrier-repair and sensitive skin products, showing up more frequently as brands embrace bio-derived lipids.
Current safety data is reassuring. Topical use at the levels seen in cosmetics is considered low risk for irritation, sensitization or systemic concerns. As with any new skincare ingredient it is wise to patch test a fresh product to confirm personal tolerance before applying it to larger areas.