Silicone gel is a soft, flexible material made from a silicon-based polymer that has widespread use in medicine, skincare, and cosmetics. In its most common consumer-facing form, it’s a topical product applied to scars to flatten, soften, and fade them. It works by forming a thin, breathable, waterproof layer over the skin that traps moisture and mimics the protective barrier function of healthy skin.
What Silicone Gel Is Made Of
At the molecular level, silicone gel is built from polydimethylsiloxane (PDMS), a synthetic polymer with a backbone of alternating silicon and oxygen atoms. Small organic groups attach to the silicon atoms, giving the material its characteristic flexibility and stability. To turn liquid silicone into a gel, manufacturers introduce chemical cross-links between polymer chains, creating a three-dimensional network. The degree of cross-linking determines whether the final product is a soft, spreadable gel or a firmer material like the silicone found in medical implants.
Medical-grade silicone gel is held to strict purity standards. It’s manufactured without harmful additives or fillers and is typically platinum-cured, which produces an ultra-pure, stable product with very low levels of extractable chemicals. These products undergo biocompatibility testing for toxicity, skin sensitization, and irritation before reaching consumers.
How It Works on Scars
When skin is wounded, its outer barrier is compromised. Water evaporates from the damaged area at a much higher rate than from intact skin, and this excessive water loss can persist for over a year after injury. Raised, thickened scars like hypertrophic scars and keloids lose even more water than flat or sunken scars. That chronic dehydration of skin cells appears to be a key driver of abnormal scarring.
Here’s the chain of events: when the outermost layer of skin dries out, surface skin cells respond by releasing chemical signals that tell deeper cells to ramp up collagen production. Excess collagen is what makes scars thick, raised, and firm. Silicone gel interrupts this cycle. When applied to a scar, it dries into a thin, transparent, flexible film that is gas-permeable but water-impermeable. This restores the skin’s natural moisture barrier, reducing water loss and rehydrating the surface layer. Once hydration normalizes, skin cells stop sending those overproduction signals, and collagen output drops back toward normal levels.
The result, over weeks to months, is a scar that gradually becomes flatter, softer, and less red.
What Silicone Gel Treats
Silicone gel is primarily used for two types of raised scars: hypertrophic scars, which stay within the boundaries of the original wound, and keloids, which grow beyond those boundaries. It’s used both to prevent these scars from forming after surgery or injury and to improve the appearance of existing ones. For keloids, silicone gel typically won’t completely resolve the scar, but it can reduce thickness and firmness.
Beyond scar management, silicone shows up in everyday cosmetics and skincare. In moisturizers and makeup primers, it creates a smooth, silky layer over the skin that reduces the appearance of fine lines and helps retain moisture. The same water-trapping property that makes it effective on scars also gives it value as a hydrating ingredient in lotions and creams, promoting skin softness and flexibility.
Gel vs. Sheets
Silicone-based scar products come in two main formats: topical gel (squeezed from a tube and applied like a cream) and adhesive silicone gel sheets (flexible patches pressed onto the skin). A randomized trial comparing the two formats in 30 surgical patients found no significant difference in efficacy between them. Both reduced scar thickness and improved appearance at similar rates.
The meaningful difference is convenience. Patients consistently rate topical gel as easier to use, largely because sheets can peel off, feel conspicuous on visible areas like the face or neck, and don’t conform well to joints or irregular surfaces. Gel, by contrast, dries invisibly and can be worn under clothing and makeup. Clinicians generally recommend choosing between the two based on scar location, lifestyle, and personal preference rather than expecting one to outperform the other.
How to Use It
Self-drying silicone gel is applied in a thin layer directly over clean, dry skin on the healed scar. It takes a few minutes to dry into a transparent film. Some users find the drying time slightly longer than expected, but a brief pass with a hair dryer on a cool setting speeds it up. Once dry, the film stays in place throughout the day and can be covered with sunscreen, moisturizer, or makeup.
For best results, the gel should be worn as many hours per day as possible. Many treatment protocols call for near-continuous wear, removing it only briefly for cleaning. Treatment duration varies depending on how the scar responds, but most people use silicone gel for several months. Newer or less severe scars tend to respond faster than older, well-established keloids.
Side Effects
Topical silicone gel is well tolerated by most people. A small number of users experience itching, rash, or skin breakdown at the application site. These reactions are generally mild and resolve when the product is removed or use is temporarily paused. If silicone causes a reaction, glycerin-based scar products offer an alternative with a similar occlusive approach.
It’s worth distinguishing topical silicone gel from injectable silicone or silicone implants, which carry different and more serious risks. Injected silicone can trigger granulomatous reactions, where the body walls off silicone particles with clusters of immune cells, causing localized swelling. Silicone breast implants can leak or rupture, provoking intense inflammation. These complications are specific to implanted or injected forms and don’t apply to the topical gels and sheets used for scar treatment and skincare.