What Is Dea Pg-Propyl Peg/Ppg-18/21 Dimethicone?
Dea Pg-Propyl Peg/Ppg-18/21 Dimethicone is a specialty silicone known technically as dimethicone copolyol bishydroxyethylamine. In simple terms it is a silicone backbone that has been chemically linked to small portions of polyethylene glycol (PEG) and polypropylene glycol (PPG). This pairing lets the ingredient offer the smooth feel typical of silicones while also being water dispersible, so it can rinse clean without leaving a heavy film.
The raw materials that give rise to this copolymer start with silica, the same mineral found in sand. Through a series of controlled reactions silica becomes polydimethylsiloxane (regular dimethicone). Chemists then graft PEG and PPG chains onto the silicone, followed by a gentle amination step that adds the bishydroxyethylamine group. Each stage is done in closed reactors under vacuum to remove residual solvents and ensure cosmetic grade purity.
Silicone chemistry began appearing in hair care during the 1970s as brands looked for ways to deliver shine without greasy oils. Early forms were water resistant and could build up, so formulators kept searching for lighter, rinseable options. By the 1990s copolyols like Dea Pg-Propyl Peg/Ppg-18/21 Dimethicone answered that need, giving hair slip and gloss yet washing out easily.
Today you will spot this ingredient in rinse-off and leave-in hair conditioners, shampoos claiming “weightless shine,” smoothing serums, curl creams and intensive masks. It also shows up in dual-action body washes and 2-in-1 products where conditioning alongside easy rinsing is a selling point.
Dea Pg-Propyl Peg/Ppg-18/21 Dimethicone’s Cosmetic Benefits/Uses
This silicone copolymer is chosen mainly for its ability to condition hair while remaining lightweight and water friendly.
Hair conditioning: The molecule forms a thin, flexible film along the hair shaft that smooths cuticles, reduces frizz and boosts shine. Because the PEG/PPG parts help it blend with water it does not weigh strands down, making it suitable for fine or oily hair. The conditioning layer also improves detangling which cuts down on breakage during brushing and styling.
Who Can Use Dea Pg-Propyl Peg/Ppg-18/21 Dimethicone
This ingredient is generally suitable for all hair and skin types including sensitive, oily and color treated strands. Because it is lightweight and water dispersible it rarely leaves residue that could weigh down fine hair or clog scalp pores. People with very reactive skin who struggle with any kind of silicone may still want to proceed with caution since idiosyncratic sensitivities are possible, though uncommon.
Dea Pg-Propyl Peg/Ppg-18/21 Dimethicone is produced from mineral-derived silica and synthetic polymers with no animal inputs so it is considered appropriate for both vegans and vegetarians. As always, overall product suitability depends on the full ingredient list not just this single component.
Current safety assessments show no evidence that the molecule is absorbed into the bloodstream in meaningful amounts, which means it is widely regarded as safe for use during pregnancy and breastfeeding. This is not medical advice; anyone who is pregnant or nursing should show the full product label to a qualified healthcare provider before adding it to a routine.
The ingredient does not increase photosensitivity and has no known interaction with sun exposure. It can even help protect hair color by smoothing the cuticle so dyes fade more slowly.
Potential Side Effects/Adverse Reactions
Responses to topical Dea Pg-Propyl Peg/Ppg-18/21 Dimethicone vary from person to person. The effects listed below are possible yet unlikely for the average user when the ingredient is properly formulated and used as directed.
- Rare allergic contact dermatitis presenting as redness itching or rash
- Eye irritation if the product accidentally runs into the eyes during rinsing
- Build-up on hair or scalp leading to limp feel or dull appearance when products are layered heavily without regular cleansing
- Occasional acne-like breakouts along the hairline in individuals extremely prone to follicular clogging
If any of these reactions occur stop using the product and consult a healthcare professional for guidance.
Comedogenic Rating
Rating: 1 / 5. Dea Pg-Propyl Peg/Ppg-18/21 Dimethicone sits on the surface of skin and hair, forming a breathable film that is easily removed with standard cleansing. Its PEG and PPG segments make it water dispersible so it is far less likely to trap oil or debris in pores compared with heavier water-resistant silicones. For this reason it is generally considered suitable for those prone to acne or breakouts. Extra-sensitive individuals who react to any film-forming agents may still prefer to limit use in leave-on facial products, but issues are uncommon.
The ingredient is also free of fatty acids and waxy esters that typically drive comedogenicity, further supporting its low score.
Summary
Dea Pg-Propyl Peg/Ppg-18/21 Dimethicone is a lightweight silicone copolymer that conditions hair by smoothing cuticles, reducing frizz and boosting shine while rinsing clean thanks to its PEG/PPG side chains. This dual nature delivers salon-like slip without the heavy buildup older silicones can cause.
Although not as famous as basic dimethicone or cyclopentasiloxane it shows up steadily in modern shampoos, conditioners and styling creams aimed at fine or oily hair where a weightless finish is key. Formulators appreciate its balance of performance and easy washout.
Current safety data classifies it as low risk for irritation, sensitization and systemic absorption, earning it a favorable profile for pregnant or breastfeeding users and all hair types. Still, any new cosmetic can surprise an individual’s skin so patch testing a finished product before full use is a smart precaution.