What Is Dimethicone Peg-7 Isostearate?
Dimethicone Peg-7 Isostearate is a hybrid silicone made by linking dimethicone, a smooth man-made oil, to polyethylene glycol and isostearic acid, a fatty acid that comes from vegetable oils. The result is a silky liquid that mixes well with both water and oil, which is not typical for regular silicones.
Silikones entered beauty products in the 1950s for their soft slip and protective feel. Chemists later tweaked them to be more versatile, and Dimethicone Peg-7 Isostearate was born as part of that push in the 1990s. Its balanced structure lets it spread easily while also helping water and oil mingle, so formulators quickly picked it up for modern skin and hair care lines.
The ingredient is made in two main steps. First, dimethicone is reacted with a small amount of propylene oxide to create a spot where other groups can attach. Next, that spot is linked to about seven units of polyethylene glycol and finally esterified with isostearic acid. The finished material looks like a clear to pale yellow fluid that feels light and silky.
You will spot Dimethicone Peg-7 Isostearate in leave-on and rinse-off items such as moisturizers, serums, primers, sunscreens, anti aging creams, hair conditioners, masks, cleansing oils, makeup removers and color cosmetics. Brands like it because it gives formulas a luxe feel without heaviness and can even act as a gentle cleansing agent in oil-based cleansers.
Dimethicone Peg-7 Isostearate’s Cosmetic Benefits/Uses
This multitasker offers several perks that make products feel smoother and work better on both skin and hair:
- Hair Conditioning: Coats the hair shaft in a thin layer that reduces frizz, boosts shine and makes strands easier to comb when wet or dry
- Skin Conditioning: Forms a breathable shield that softens rough spots and leaves skin feeling silky with a non-greasy finish
- Emollient: Fills in tiny gaps on the skin surface helping to smooth texture and lock in moisture for a supple look
Who Can Use Dimethicone Peg-7 Isostearate
Thanks to its light silky feel, Dimethicone Peg-7 Isostearate suits most skin types including dry, normal, combination and even oily skin because it conditions without leaving a greasy film. Its low occlusion and good spreadability mean it is generally comfortable for sensitive skin too, though anyone with a known silicone allergy should avoid it.
The ingredient is made from synthetic silicone, plant based isostearic acid and petroleum or plant derived PEG so it contains no animal by-products. On its own it is considered suitable for vegans and vegetarians, but users should still check that the finished product aligns with cruelty free standards if that matters to them.
Current safety data show no reproductive or developmental risks when used topically, so products containing Dimethicone Peg-7 Isostearate are normally viewed as safe for pregnant or breastfeeding women. This is not medical advice; anyone expecting or nursing should confirm suitability with a qualified health professional before adding new products to their routine.
The molecule does not absorb UV light or make the skin more reactive to the sun, so there is no added risk of photosensitivity. It also plays nicely with common actives such as retinoids, vitamin C and acids, making it easy to slot into almost any regimen.
Potential Side Effects/Adverse Reactions
Side effects from topical Dimethicone Peg-7 Isostearate differ from person to person. The points below outline potential reactions but most people will not notice any problems when the ingredient is used at normal levels in a well formulated product.
- Mild skin irritation or redness in those who are sensitive to silicones or PEGs
- Temporary clogged pores or breakouts for individuals who are extremely acne prone and react to heavier film formers
- Eye stinging or watering if the product accidentally gets into the eyes
- Build up on hair shafts leading to a weighed down feel if not cleansed properly between uses
- Rare allergic contact dermatitis presenting as itching or rash
If any of these reactions occur stop using the product and seek advice from a healthcare professional or dermatologist.
Comedogenic Rating
Rating: 1/5
Dimethicone Peg-7 Isostearate earns a low score because its silicone backbone is already considered non-pore-clogging and the attached PEG and isostearic acid chains make the molecule even more spreadable and water compatible, so it rinses away easier than heavier silicones. This lightweight profile means it rarely traps sebum or dead cells long enough to spark blemishes.
Most acne-prone users can apply products containing this ingredient without seeing a surge in breakouts, though results always depend on the full formula and individual skin behavior.
Worth noting: if the product also contains rich butters or waxes the overall comedogenic load can rise, so judge each formula as a whole rather than the ingredient in isolation.
Summary
Dimethicone Peg-7 Isostearate is a silky hybrid that conditions skin and hair, smooths texture and acts as an emollient by laying down a thin breathable film that locks in moisture while adding slip. Its amphiphilic structure lets it mingle with both oil and water phases, which boosts spreadability and helps cleansers lift away makeup and debris.
The ingredient sits in the middle of the popularity chart: not as talked about as classic dimethicone yet favored by many formulators looking for a lighter feel and easy rinse-off performance. You will mainly meet it in modern moisturizers, primers, sunscreens, cleansing oils and hair conditioners.
Current research and industry reviews label it as low risk with minimal irritation potential in leave-on and rinse-off products. Still, everyone’s skin is unique so do a quick patch test when trying something new to make sure it plays nicely with your complexion.