Dimethicone: Comedogenic Rating & Safety Profile
Also known as: Polydimethylsiloxane · PDMS
A breathable silicone that forms a smooth, flexible film on the skin, locking in moisture and giving products their silky glide.
Quick facts about Dimethicone
Low Risk
0 = won't clog pores · 5 = highly pore-clogging
Safe
0 = inert · 5 = often irritating
Silicones
Generally considered safe
Typically yes
Polydimethylsiloxane, PDMS
Quick verdict
Dimethicone is a silicone with a low risk comedogenic profile (1/5) and safe irritancy (0/5). A breathable silicone that forms a smooth, flexible film on the skin, locking in moisture and giving products their silky glide.
What is Dimethicone?
Dimethicone (also called polydimethylsiloxane or PDMS) is a synthetic silicone polymer — long chains of silicon-oxygen units with methyl side groups. It is chemically inert, exceptionally well-tolerated and has been used in medicine for decades, including in NICU infant skin protection and post-surgical scar therapy. In skincare it forms a thin, breathable film over the skin that smooths surface texture, reduces transepidermal water loss and gives products their characteristic silky slip. It is one of the most studied and safest cosmetic ingredients available.
Comedogenic Rating: What 1/5 Means for Your Skin
Dimethicone is rated 0–1/5 comedogenic — effectively non-comedogenic for the vast majority of users. The 'silicones suffocate skin' myth has been thoroughly debunked: the polymer matrix is permeable to oxygen and water vapour, and the molecule is too large to physically enter a follicle. People with severe acne or fungal acne occasionally report breakouts, but these are usually triggered by something else in the formula (occlusive butters, fragrance) rather than the dimethicone itself.
Benefits for skin
- Reduces transepidermal water loss without occluding pores
- Creates an even canvas for makeup application
- Soothes irritation and protects barrier-impaired skin
- Inert and non-reactive — exceptionally well-tolerated
Potential side effects & who should avoid it
Dimethicone has one of the lowest documented irritancy and allergy rates of any skincare ingredient. There are essentially no side effects in healthy adult skin. It washes off easily with a standard cleanser — there is no evidence of accumulation or 'build-up' on the skin. The myth that silicones cause acne stems mostly from anecdotal forum reports rather than controlled research.
Best for
- All skin types
- Sensitive
- Compromised barrier
Avoid if
No widely reported groups need to avoid this ingredient. Patch-test if you have a history of sensitivities.
How to use Dimethicone safely
No special precautions needed. Layer dimethicone-containing products at any step of your routine. They are particularly useful as a primer step before makeup, or as a barrier layer after retinoids.
Commonly found in
Dimethicone is in primers, moisturisers, sunscreens, foundations, hair serums, scar gels and after-procedure ointments. It is also a key ingredient in many medical-grade barrier creams.
Found Dimethicone in your skincare?
Paste the full ingredient list into our INCI Analyser to see how this ingredient interacts with everything else in the formula.
Frequently asked questions
Want the full picture on pore-clogging ingredients? Read our complete guide to comedogenic ingredients for the dermatology research behind the 0–5 scale and the full list of high-risk ingredients to avoid.
Written by ScanSkinAI Team · Last updated May 2026
This information is for educational purposes only. Always patch-test new products and consult a dermatologist if you have specific skin concerns.