The best time to start using scar cream depends on the type of cream, but the general rule is to wait until the wound has fully closed. For most surgical or injury scars, that means starting a silicone-based scar cream about two to three weeks after the wound occurs, once the surface skin has sealed over completely. Starting too early on an open wound risks irritation and infection; waiting too long means missing the window when scar tissue is most responsive to treatment.
The First Two to Three Weeks: Moisture, Not Scar Cream
Right after a wound closes (or right after surgery), the priority is keeping the area moist and protected. During this initial phase, simple petroleum jelly or antibiotic ointment applied twice daily helps the skin resurface faster. These aren’t scar treatments in the traditional sense. They create a moist environment that speeds up the regrowth of surface skin cells, which is the foundation everything else builds on.
This initial healing period typically lasts two to three weeks. By the end of it, the wound has built enough surface integrity and tensile strength for the next phase. Pain around the incision or wound drops noticeably, and the edges of the wound should be fully sealed with no scabbing, oozing, or gaps. That sealed surface is your signal: the wound is ready for actual scar cream.
When to Start Silicone-Based Scar Cream
Silicone gel is the most studied and widely recommended topical scar treatment. It works by forming a thin, breathable layer over the scar that traps moisture in the skin. Scar tissue has a thinner, less mature outer barrier than normal skin, so it loses water faster. That excess water loss triggers a chain of inflammatory signals that ramp up collagen production, which is exactly what makes scars raised, thick, and firm. Silicone gel interrupts this cycle. By reducing water loss, it dials down the inflammatory signaling and slows excess collagen buildup.
Start silicone gel once the wound has fully closed and the surface skin (even if pink and fragile) covers the entire area. Current clinical guidelines recommend wearing silicone gel or silicone sheets for at least 12 hours per day and continuing until the scar matures. That timeline varies, but plan on a minimum of three months of consistent daily use. For larger or more aggressive scars, six months or longer is common. The key is consistency: silicone works through sustained hydration, so sporadic use won’t deliver meaningful results.
Onion Extract Creams: Earlier Start, Shorter Course
Products like Mederma, which contain onion extract, can be started on the day of wound closure (or even the day of surgery in some protocols) and are typically used for one to three weeks during the early healing phase. They overlap with the moisture-maintenance stage. Clinical guidelines recommend applying onion extract creams twice daily for at least 28 days to see improvements in scar thickness, redness, itching, and pigmentation.
A head-to-head comparison found that silicone gel containing onion extract and aloe vera performed comparably to silicone sheets alone for preventing raised scars after surgery. Both reduced pain and itchiness. The combination gel scored slightly better on scar pliability (how soft and flexible the scar felt). In practice, many people start with an onion extract product early on, then transition to a silicone-based gel for the longer haul.
What About Vitamin E Creams?
Vitamin E is one of the most popular home remedies for scars, but the clinical evidence is disappointing. In a controlled trial of 159 patients with burn scars treated with topical vitamin E for four months, researchers found no measurable benefit for scar thickness, appearance, or range of motion. A separate double-blind trial found that vitamin E added to an emollient performed no better than the emollient alone after surgical wound closure.
Worse, nearly a third of patients in one study reported skin reactions to vitamin E cream, including contact dermatitis and eczema-like rashes. Some researchers concluded that topical vitamin E actually worsened the cosmetic appearance of scars in certain cases. The one exception: when vitamin E was combined with silicone sheets, 95% of patients saw their hypertrophic scars improve by 50% after two months, compared to 75% with silicone sheets alone. That suggests the silicone was doing most of the heavy lifting, with vitamin E possibly adding a modest boost in that specific combination.
Which Scar Types Respond to Cream
Scar creams work best on newer scars that are still metabolically active, meaning the tissue is still remodeling and laying down collagen. This phase can last anywhere from several months to about two years after injury. Silicone gels and sheets have proven effective for hypertrophic scars (raised, firm scars that stay within the wound’s original boundaries), keloids (raised scars that grow beyond the wound edges), and post-burn scars.
Older, mature scars are a different story. Steroid-based treatments, for example, are generally not useful on older scars because the tissue is no longer actively producing excess collagen. However, topical formulations containing certain calcium channel blockers have shown promise for softening and breaking down older, inactive scars, potentially reducing the need for surgical revision. For flat scars with discoloration, ingredients like niacinamide (which has a very low irritation profile and can be used daily) and low-strength retinoids can help even out skin tone over time.
If your scar is significantly raised or continues to grow after several months of topical treatment, creams alone may not be enough. Silicone sheets are particularly useful for large, flat-surface keloids and can be used alongside other treatments.
Sun Protection During Scar Healing
After the initial two to three week healing window, sun protection becomes critical. Fresh scars are highly susceptible to pigmentation changes from UV exposure. A new scar exposed to sunlight can darken permanently, turning noticeably darker than the surrounding skin. This is especially true for people with medium to dark skin tones.
Apply broad-spectrum sunscreen over your scar (or over your silicone gel layer) whenever the area will be exposed to sunlight. This is one of the simplest and most impactful things you can do during the first year of scar healing. Some scar creams now include SPF, which simplifies the routine, but any sunscreen rated SPF 30 or higher works.
How to Layer Scar Care Throughout the Day
A practical daily routine looks like this: apply silicone gel in the morning and let it dry to form a thin film before getting dressed. This maintains hydration and barrier function throughout the day. Reapply after bathing or if the film is disrupted. If you’re using an onion extract cream during the early weeks, apply it twice daily as directed, then transition to silicone gel once you’re past the initial healing phase. Gentle scar massage can begin after the wound is fully closed (typically at the two to three week mark) and complements topical treatment by helping soften and flatten the tissue.
For silicone sheets, aim for at least 12 hours of wear per day. Many people wear them overnight and switch to silicone gel during the day for convenience and discretion. The combination of sheets at night and gel during the day provides near-continuous coverage without the awkwardness of visible patches.
When Scar Cream Won’t Help
Scar creams are not appropriate for open wounds, actively infected skin, or areas with stitches that haven’t been removed. Applying silicone or onion extract to broken skin can cause irritation and delay healing. If you notice redness, itching, or a rash developing around the scar after starting a cream, you may be reacting to one of the product’s ingredients. Common culprits in wound care products include propylene glycol (found in many gels), certain alcohol-based emulsifiers, and colophonium derivatives used as adhesives in silicone sheets. Switching brands or formulations usually resolves the issue.
Atrophic scars (indented scars like acne pitting or stretch marks) generally don’t respond well to topical scar creams alone, since the problem is lost tissue volume rather than excess collagen. Silicone and onion extract are designed to flatten and soften raised tissue, not fill in depressions.