What Is Hexamethylene Sesqui-Hydroxystearamide?
Hexamethylene Sesqui-Hydroxystearamide is made by joining hexamethylenediamine with hydroxystearic acid, creating a mix of mono- and diamides. Both starting materials come from well-established industrial sources: hexamethylenediamine begins with petroleum-derived compounds while hydroxystearic acid is usually obtained from castor oil. Through a controlled heating process called amidation, chemists bond the two, then purify the result until it meets cosmetic-grade standards.
The ingredient appeared in cosmetic labs in the late 1990s as formulators searched for alternatives to traditional thickeners that could deliver a smoother, lighter feel. Its ease of use and reliable performance helped it move from niche laboratory tests into mainstream skin care by the early 2000s.
Today you will most often spot Hexamethylene Sesqui-Hydroxystearamide in products where a silky, non-greasy texture matters. These include light creams, lotions, gel moisturizers, sheet masks, anti-aging serums and even some sunscreens. Because it works well across a wide pH range, brands use it in both water-based and oil-rich formulas.
Hexamethylene Sesqui-Hydroxystearamide’s Cosmetic Benefits/Uses
Its main role in a formula is to keep the product at just the right thickness so it feels pleasant and spreads evenly on skin. Acting as a viscosity controller, it prevents watery products from running off your face yet stops thicker creams from feeling heavy or sticky. Consistent viscosity also helps actives stay evenly dispersed, which supports uniform application and can boost overall product performance.
Who Can Use Hexamethylene Sesqui-Hydroxystearamide
This texture-smoothing helper works for most skin types including normal, dry, combination and oily skin because it sits on the surface without adding oiliness or stripping moisture. Sensitive skin usually tolerates it well since it is chemically stable and fragrance free, yet those with known amide or castor-oil allergies should stay cautious and read labels closely.
The ingredient is created from castor-derived hydroxystearic acid and petroleum-derived hexamethylenediamine, neither of which come from animals so it is suitable for vegans and vegetarians.
Current safety reviews show no specific risks for pregnant or breastfeeding women at the low levels used in cosmetics. This is not medical advice and anyone who is expecting or nursing should still discuss any new skincare product with a doctor first just to be safe.
Hexamethylene Sesqui-Hydroxystearamide does not make skin more reactive to sunlight so it is not considered photosensitising. It also does not interfere with common actives such as vitamin C, niacinamide or retinoids, letting you layer it with most routines without concern.
Potential Side Effects/Adverse Reactions
Reactions to topical Hexamethylene Sesqui-Hydroxystearamide differ from person to person. The points below cover possible side effects yet they are uncommon when the ingredient is used at the concentrations normally found in cosmetics.
- Mild skin irritation: a tingling or stinging sensation that usually fades after rinsing or discontinuing use
- Redness or flushing: temporary warmth or color change in the area of application
- Contact dermatitis: rare cases of itching or rash in individuals allergic to amide structures or castor-derived ingredients
- Eye irritation: watering or burning if the product accidentally gets into the eyes
If you notice any of these effects stop using the product and consult a healthcare professional or dermatologist for guidance.
Comedogenic Rating
Rating: 1 out of 5. Hexamethylene Sesqui-Hydroxystearamide stays mostly on the surface and is used at very low levels, so it does not clog pores the way heavier oils or waxes can. Its molecular structure leans more toward a dry, powdery feel than an oily film, which keeps it from blocking sebaceous ducts.
That makes it generally suitable for acne-prone or breakout-prone skin.
No published data suggest that it aggravates fungal acne, and its castor-derived portion is highly purified, minimizing residue that yeast might feed on.
Summary
Hexamethylene Sesqui-Hydroxystearamide is a viscosity controller that fine-tunes texture so creams feel light and gels do not run. It achieves this by forming a delicate network of amide bonds that thickens both water and oil phases without greasiness, keeping active ingredients evenly suspended for smooth application.
The ingredient sits in the quietly dependable middle ground of beauty chemistry. It is not a headline-grabbing star like retinol, yet formulators reach for it when they need a silky finish that holds steady in a wide pH range.
Safety reviews rate it as low risk with rare irritation reports, and it scores just 1 on the comedogenic scale. As with any new cosmetic, do a small patch test first to make sure your skin agrees before using a full-size product.