What Is Sodium Pg-Propyldimethicone Thiosulfate Copolymer?
Sodium Pg-Propyldimethicone Thiosulfate Copolymer is a specialty silicone derivative created by linking dimethicone units with propylene glycol and adding a thiosulfate group that is then neutralized with sodium. This gives the material a hybrid nature: the familiar smooth feel of silicones combined with a water friendly, lightly charged side that helps it disperse in water based products.
The earliest silicone hair serums of the 1990s inspired chemists to search for silicones that rinsed out more easily and could carry extra benefits. By attaching propylene glycol and thiosulfate, manufacturers produced a version that clings to damaged hair without heavy buildup. Over time it found a place not just in salon products but also in mainstream shampoos, conditioners and leave-in sprays.
Commercial production starts with dimethyl siloxane chains reacted with a propylene glycol derivative that contains an epoxide ring. This epoxide opens and bonds to the silicone backbone. A controlled oxidation step introduces the thiosulfate group which is finally neutralized with sodium hydroxide to form a stable salt. The finished polymer is usually supplied as a clear fluid or as a pre-diluted solution for easy mixing.
You will most often spot this ingredient in rinse-off conditioners, leave-in creams, smoothing serums, anti-frizz sprays, color protection treatments and some styling gels. It occasionally appears in skin care masks or primers where a weightless film is desired.
Sodium Pg-Propyldimethicone Thiosulfate Copolymer’s Cosmetic Benefits/Uses
This multitasking polymer improves both the performance and the sensory feel of many beauty formulas
- Film forming: Creates a thin flexible layer over hair or skin that locks in moisture, smooths cuticles, boosts shine and offers light humidity resistance so styles last longer
- Hair conditioning: Deposits selectively on damaged areas, reducing friction, making detangling easier and leaving hair softer without the heavy or greasy feel associated with older silicones
Who Can Use Sodium Pg-Propyldimethicone Thiosulfate Copolymer
This silicone-based polymer is considered gentle enough for all skin types, including dry, normal, combination and sensitive skin. Its lightweight film holds water without creating a heavy occlusive layer so it rarely aggravates oily or acne-prone complexions. People with extremely reactive or silicone-sensitized skin should still proceed cautiously, as with any new ingredient, but most users tolerate it well.
The material is fully synthetic and produced without animal by-products which makes it suitable for both vegans and vegetarians. As always, those lifestyles should verify that the entire finished product is cruelty free and not just the single raw material.
Current safety data show no known reproductive or developmental concerns. Pregnant or breastfeeding women can generally use products containing this copolymer, yet this is not medical advice and anyone who is expecting or nursing should run all personal care products past a qualified healthcare professional just to be safe.
Sodium Pg-Propyldimethicone Thiosulfate Copolymer does not increase photosensitivity. It can be worn during daytime without raising the risk of sunburn although a separate sunscreen is still recommended for UV protection.
Potential Side Effects/Adverse Reactions
Reactions to topical ingredients differ from person to person. The following list covers potential side effects of Sodium Pg-Propyldimethicone Thiosulfate Copolymer in cosmetic use. When the ingredient is correctly formulated most people will not experience these issues.
- Mild skin or scalp irritation such as redness itching or a burning sensation
- Contact allergy that may appear as localized rash or hives in highly sensitive individuals
- Product buildup leaving hair feeling heavy or limp if used excessively or without proper cleansing
- Follicle congestion leading to small bumps on the scalp or hairline in rare cases
If any discomfort occurs discontinue use and seek advice from a medical professional.
Comedogenic Rating
Rating: 1/5
Sodium Pg-Propyldimethicone Thiosulfate Copolymer has a large, slick silicone backbone that tends to sit on top of skin rather than soaking into pores, which keeps its clogging potential low. Its partial water compatibility makes it easier to wash away than heavier dimethicone fluids, further reducing residue that might trap dead cells or sebum. Because of this it is generally acceptable for acne-prone users, though very oily skin might still prefer lighter formulas. Formulation matters, so a product loaded with oils or waxes can override the ingredient’s low pore-blocking profile.
Summary
Sodium Pg-Propyldimethicone Thiosulfate Copolymer acts mainly as a film former and hair conditioner. The silicone chain smooths cuticles and fills surface irregularities while the propylene glycol and thiosulfate segments let the polymer disperse in water and anchor to damaged spots. The result is a lightweight, glossy coating that tames frizz, boosts slip and seals in moisture without the heavy feel of classic silicones.
It is not yet a household name but formulators looking for modern, rinse-friendly silicones have been adding it to salon and mid-tier haircare, so its presence is slowly spreading. Current safety reviews show a low risk of irritation, sensitization or pore blockage when used at normal cosmetic levels. As with any new product, doing a quick patch test is still the smartest way to make sure your skin or scalp stays happy.