What Is Isostearic/Myristic Glycerides?
Isostearic/Myristic Glycerides are a blend of glycerides formed when glycerol is combined with two fatty acids – isostearic acid, a branched version of stearic acid, and myristic acid, a 14-carbon saturated fat. Both acids are most often sourced from plant oils such as coconut, palm kernel and sometimes rapeseed, though animal sources can be used as well. During production the fatty acids are purified, then reacted with glycerol in a process called esterification. The result is a semi-solid, waxy material that is easy to work with in both water-based and oil-based formulas.
Cosmetic chemists started using this ingredient in the 1960s when they needed reliable, skin-friendly emulsifiers that also left a soft feel on the skin. Its balanced mix of branched and straight-chain fatty acids makes it stable over a wide temperature range, which helped it gain a place in everything from lotions to color cosmetics.
Today you will spot Isostearic/Myristic Glycerides in moisturizers, sunscreens, makeup foundations, cleansing balms, hair conditioners, baby care lotions, sheet mask serums and many anti-aging creams where a silky, non-greasy finish is important.
Isostearic/Myristic Glycerides’s Cosmetic Benefits/Uses
This ingredient pulls double duty in a formula, offering both texture and skin feel benefits
- Skin Conditioning: The glyceride blend forms a light occlusive layer that helps smooth rough patches and reduce moisture loss, leaving skin soft without a heavy residue
- Emulsifying: It binds water and oil together so creams stay uniform and stable, preventing separation over time and giving products a pleasing glide during application
Who Can Use Isostearic/Myristic Glycerides
Thanks to its lightweight occlusive qualities Isostearic/Myristic Glycerides tends to work well for normal, dry and combination skin. Oily or very acne-prone complexions usually tolerate it too because the branched isostearic portion keeps the feel less greasy than straight fatty acids, though extremely breakout-prone users may prefer to monitor how their skin responds.
The material itself can be produced from vegetable or animal fats. Most cosmetic batches come from coconut, palm or rapeseed oil so they are suitable for vegans and vegetarians when clearly labeled as plant-derived or when the finished product carries a certified vegan logo.
This ingredient is not known to interfere with pregnancy or breastfeeding. It is considered low risk for systemic absorption and has no documented hormone-related activity, yet this is not medical advice. Anyone who is pregnant or nursing should show the full ingredient list of their products to a qualified healthcare provider just to be safe.
Isostearic/Myristic Glycerides do not increase photosensitivity and can be used morning or night without affecting how skin reacts to sunlight. It is also fragrance-free and does not contain common allergens like nuts gluten or soy, which broadens its compatibility for sensitive users.
Potential Side Effects/Adverse Reactions
Reactions to topical Isostearic/Myristic Glycerides differ from person to person. The points below outline potential side effects that could occur, although most people experience none of them when the ingredient is properly formulated and used as directed.
- Mild skin irritation such as redness or stinging
- Contact dermatitis in individuals allergic to fatty acid derivatives
- Temporary clogged pores leading to minor breakouts in very acne-prone skin
If any discomfort or unexpected reaction develops discontinue use and seek advice from a healthcare professional or dermatologist.
Comedogenic Rating
Rating: 1 / 5
Isostearic/Myristic Glycerides sit near the bottom of the clogging scale because the branched structure of isostearic acid prevents the molecules from packing tightly inside pores while the glyceride form makes them bulkier and less likely to penetrate deeply. Formulators often use the blend to add slip without the greasy buildup associated with straight-chain fats.
Most people prone to acne or breakouts can use products containing this ingredient without major concern, though extremely reactive skin should still observe how it responds.
Keep in mind that overall formula design, concentration, and the presence of other heavier oils can nudge the real-world comedogenicity up or down despite the low intrinsic score.
Summary
Isostearic/Myristic Glycerides act as a dual-purpose helper in cosmetics. As an emulsifier they hold water and oil together so creams stay smooth and stable. As a skin conditioner they leave a light, silky film that reduces moisture loss and makes skin feel soft without an oily after-feel.
The ingredient enjoys steady but quiet popularity behind the scenes. It is widely used by chemists who like its reliability and pleasant texture, yet it rarely appears in marketing headlines so many consumers have never heard of it.
Safety data positions it as low risk for irritation, sensitization, or hormonal activity, and it carries a very low comedogenic rating. Still, every skin is unique so do a quick patch test whenever you try a new product that lists Isostearic/Myristic Glycerides near the top of the ingredient list.