What Is Peg-15 Dedm Hydantoin Stearate?
Peg-15 Dedm Hydantoin Stearate is a lab-made ingredient created by attaching about 15 units of ethylene oxide to a molecule called 1,3-bis(2-hydroxyethyl)-5,5-dimethylimidazolidine-2,4-dione and then linking that new chain to stearic acid, a fatty acid found in plants and animal fats. The result is a waxy, water-friendly compound that blends smoothly into creams and lotions. Chemists began exploring this type of hydantoin compound in the late 1970s when the cosmetics industry was searching for gentler options to keep products fresh. By the early 1990s Peg-15 Dedm Hydantoin Stearate was added to ingredient lists because it helped preserve formulas without the strong scent or irritation that older preservatives sometimes caused.
Manufacturing starts with stearic acid, often sourced from coconut or palm oil. The hydantoin core is produced from simple building blocks like glycol and dimethyl urea. Each piece is reacted under controlled heat and pressure, then purified. Finally the ethoxylation step adds the 15 polyethylene glycol units, giving the ingredient its “PEG-15” label. The finished material is a solid or thick paste that melts into oil or water phases during product blending.
You will most often find Peg-15 Dedm Hydantoin Stearate in moisturizers, facial masks, serums, sunscreens, body lotions and hair conditioners. Formulators like it because it works in both water-rich and oil-rich systems, so it can protect everything from light gels to rich butters.
Peg-15 Dedm Hydantoin Stearate’s Cosmetic Benefits/Uses
This ingredient is valued mainly for one key job in personal care formulas.
As an antimicrobial it limits the growth of bacteria, mold and yeast that can spoil a product or irritate skin. By keeping the formula clean it helps extend shelf life, supports product safety and lets you store your favorite cream on the bathroom shelf without worry.
Who Can Use Peg-15 Dedm Hydantoin Stearate
Most skin types, including normal, oily, dry and combination, can use products that contain Peg-15 Dedm Hydantoin Stearate because it is added at low levels and is not greasy or pore clogging. People with very sensitive or eczema-prone skin should still watch for any discomfort since hydantoin preservatives can occasionally trigger irritation in highly reactive skin.
The ingredient itself can be suitable for vegans and vegetarians when the stearic acid portion is sourced from plants like palm or coconut oil, which is common in modern cosmetic supply chains. If animal-derived stearic acid is used the finished ingredient would no longer be vegan friendly, so those following a strict plant-based lifestyle may want to check with the brand for confirmation.
No research has flagged this preservative as unsafe for women who are pregnant or breastfeeding when used in rinse-off or leave-on skincare. That said this is not medical advice and anyone who is pregnant or nursing should review any cosmetic product with their doctor to be extra safe.
Peg-15 Dedm Hydantoin Stearate does not make skin more sensitive to sunlight and there are no known interactions with common medications or topical actives at the small percentages used in cosmetics.
Potential Side Effects/Adverse Reactions
Reactions to topical Peg-15 Dedm Hydantoin Stearate vary from person to person. The points below list potential side effects but most users will not experience them when the ingredient is included at proper levels in a well-formulated product.
Skin redness or mild burning
Dry or flaky patches in people with already compromised skin barriers
Allergic contact dermatitis in individuals sensitive to hydantoin preservatives or trace formaldehyde
Eye irritation if a product accidentally enters the eyes
Stinging on freshly shaved or broken skin
If any uncomfortable reaction develops stop using the product and seek advice from a qualified healthcare professional.
Comedogenic Rating
Rating: 1 / 5 (very low)
Peg-15 Dedm Hydantoin Stearate contains a stearic acid tail, yet the PEG portion makes the molecule water friendly so it sits on skin lightly rather than building up in pores. It is also used at preservative levels well under 1 % of a formula, keeping the overall oil load tiny. Combined, these factors mean there is little chance it will block pores or worsen blackheads.
Most people who are prone to acne can use products with this ingredient without issue, though everyone’s skin is unique.
Because its job is preservation, not texture, brands rarely include it in heavy amounts that could change the pore-clogging profile of a product. Other richer ingredients in the same formula will play a bigger role in breakouts than this preservative does.
Summary
Peg-15 Dedm Hydantoin Stearate is added to skincare and haircare primarily as an antimicrobial agent that keeps bacteria, yeast and mold from spoiling a product. The PEG chain lets it dissolve into water phases while the stearate anchor nestles in oil phases, so it can patrol the whole formula and guard it from microbes.
It is not a headline ingredient and you will usually spot it halfway down an ingredient list, yet chemists appreciate its reliable preserving power and mild feel on skin. Its popularity is steady but modest because many brands opt for broader spectrum preservative blends instead of single agents.
Current research and industry safety reviews rate it as low risk at the small percentages used in cosmetics. Still, every skin type is different so it is wise to patch test any new product that contains this or any other preservative to confirm personal comfort.