What Is Peg-100/Ipdi Copolymer?
Peg-100/Ipdi Copolymer is a man-made ingredient created by linking two main parts: polyethylene glycol with about 100 repeating units (PEG-100) and a ring-shaped molecule called isophorone diisocyanate (IPDI). When chemists connect these pieces they form a flexible yet stable polymer that blends easily with water and oil.
Production starts with ethylene oxide, a gas that builds the long PEG chain. This chain is then reacted with IPDI under carefully controlled heat and pressure to form safe urethane bonds. The finished material looks like a clear to slightly hazy liquid and has no smell, making it easy to add to cosmetic mixes.
The beauty industry began exploring this polymer in the late 1990s when formulators needed gentler ways to keep creams and lotions from separating. Over time its reliable performance and mildness secured a place in many modern products.
You will most often see Peg-100/Ipdi Copolymer in daily moisturizers, anti-aging serums, face masks, sunscreens, hair conditioners, styling creams and long-wear makeup. It helps these products keep a smooth feel and consistent texture from the first use to the last.
Peg-100/Ipdi Copolymer’s Cosmetic Benefits/Uses
Formulators lean on this polymer because it quietly improves how a product looks, feels and performs on the skin or hair.
- Binding: Helps hold powders, oils and active ingredients together so every dose delivers the same blend of goodies
- Emulsion stabilising: Keeps water and oil phases from splitting which means creams stay creamy and lotions stay silky even after months on the shelf
- Viscosity controlling: Gives the right thickness so a product spreads easily without running off the skin or feeling too heavy
Who Can Use Peg-100/Ipdi Copolymer
This polymer is generally well tolerated by all skin types including oily, dry, combination and mature skin because it is non-sensitising and does not clog pores. Extremely sensitive or allergy-prone individuals who react to polyethylene glycols should proceed with caution since the PEG portion could trigger a response.
Peg-100/Ipdi Copolymer is synthesised from petrochemical feedstocks with no animal-derived inputs so it is suitable for vegans and vegetarians.
Current data show no specific risks for pregnant or breastfeeding women when the ingredient is used topically in cosmetics. That said this is not medical advice and anyone who is pregnant or nursing should ask a doctor before starting new skincare just to be safe.
The polymer does not absorb UV light and is not known to cause photosensitivity. It has no recognised interactions with common actives like retinoids or acids so it can sit comfortably in most routines.
Potential Side Effects/Adverse Reactions
Responses to any cosmetic ingredient can vary from person to person. The effects listed below are potential side effects of Peg-100/Ipdi Copolymer and are unlikely to occur for most users when the ingredient is used correctly by the manufacturer.
- Redness, itching and mild irritation on very sensitive skin
- Rare allergic contact dermatitis in people already sensitised to PEGs or isocyanates
- Eye stinging if a product accidentally enters the eyes
- Heavy or greasy feel on extremely oily skin when used in high concentrations
If you experience any unwanted reaction stop using the product and consult a healthcare professional or dermatologist.
Comedogenic Rating
Rating: 1 / 5 (very low)
Peg-100/Ipdi Copolymer is primarily water-attracting and forms a large, flexible molecule that sits on the surface rather than sinking deep into pores. It lacks heavy oils or waxes that usually cause congestion and is used at modest levels, so the likelihood of it trapping sebum is minimal.
Suitable for acne-prone or breakout-prone skin, though the overall formula still matters because richer accompanying ingredients could tip the balance.
Worth noting: in leave-on products layered under thick makeup or sunscreen, build-up from multiple film-formers might contribute to a heavy feel for very oily skin types. Regular cleansing helps avoid this.
Summary
Peg-100/Ipdi Copolymer acts as a binder, emulsion stabiliser and viscosity controller by linking water and oil phases, holding actives in place and tweaking thickness for a smooth glide. Its flexible polymer chain creates a light film that keeps formulas uniform from the first pump to the last drop.
The ingredient is a behind-the-scenes workhorse rather than a buzzy superstar, yet formulators appreciate its reliability so you will quietly find it in a fair share of creams, lotions and hair products.
Current safety data show very low toxicity, negligible absorption and rare irritation. As with any new cosmetic always patch test to spot personal sensitivities before full-face or full-body use.