Hypertrophic scars can be treated effectively with a combination of silicone products, steroid injections, and pressure therapy, with most scars showing significant improvement over several months. Unlike keloids, which spread beyond the original wound, hypertrophic scars stay within the boundaries of the injury and often partially flatten on their own over time. That natural tendency to improve means treatment can speed up what your body is already trying to do.
What Makes a Scar Hypertrophic
Normal wound healing involves a careful balance between building new tissue and breaking down the temporary scaffolding. In a hypertrophic scar, that balance tips toward overproduction. Specialized cells called fibroblasts deposit far more collagen than gets broken down, creating a dense, raised mass of tissue. The structural hallmark is something called a collagen nodule: a tightly packed cluster of fibroblasts surrounded by highly organized collagen fibers running in one direction. Mature, flat scars don’t contain these nodules.
The result is a raised, firm, often reddish or pink scar that may itch. Hypertrophic scars are most common after burns, surgical incisions, and wounds in areas of high skin tension like the chest, shoulders, and joints. They typically develop within weeks of an injury and may continue thickening for several months before stabilizing.
Silicone: The First-Line Treatment
International clinical guidelines identify silicone gel sheeting as one of only two treatments with strong enough evidence to earn a formal recommendation. Silicone works by hydrating the outer layer of skin over the scar, which appears to regulate collagen production and reduce the signals that drive excessive scarring. In animal models, silicone sheeting reduced hypertrophic scar formation by 80 percent.
The key to silicone therapy is consistency. Sheets or strips need to be worn for at least 12 hours a day, and ideally closer to 24 hours, for a minimum of two to three months. You remove them only to wash the skin and the sheet, then reapply. Silicone gel (the tube form you spread on like a lotion) is a practical alternative for scars in visible areas or on joints where sheets won’t stay put. Both forms are available over the counter. The treatment is painless and has virtually no side effects beyond occasional mild skin irritation.
Steroid Injections for Thicker Scars
The other treatment with strong guideline support is corticosteroid injections directly into the scar. These injections reduce inflammation, slow collagen production, and can soften and flatten a raised scar noticeably. The standard approach uses a corticosteroid mixed with a local anesthetic, delivered through a fine needle.
Sessions are spaced three to four weeks apart and repeated until the scar has flattened to a satisfactory degree. Most people need several rounds. The injections can be uncomfortable because scar tissue is dense, but the local anesthetic helps. Possible side effects include temporary lightening of the skin around the injection site, thinning of surrounding tissue, and small visible blood vessels. These risks are generally manageable and your provider will adjust the concentration based on how your scar responds.
Pressure Therapy
Pressure garments are particularly effective for hypertrophic scars from burns. The sustained compression appears to restrict blood flow to the scar, which limits the oxygen and nutrients available for excessive collagen production. Research indicates that a minimum of 15 mmHg of pressure is needed for effectiveness, with clinical guidelines recommending 24 to 30 mmHg.
The commitment is significant. Pressure garments need to be worn for six to 12 months, essentially all day and night, removed only for bathing. Custom-fitted garments work best because consistent, even pressure across the scar is what drives results. For ear scars, commercially available pressure earrings serve the same purpose on a smaller scale. This approach works best when started early, before the scar has fully matured.
Laser Treatment
Pulsed dye lasers, which target blood vessels using wavelengths around 585 to 595 nanometers, can reduce the redness and thickness of hypertrophic scars. The laser selectively heats the small blood vessels feeding the scar, which reduces blood supply and helps the scar soften and flatten. Multiple sessions are typically needed, and the response depends on factors like the scar’s age, thickness, and location. Laser therapy is often used alongside other treatments rather than as a standalone option.
Options for Stubborn Scars
When silicone, steroids, and pressure therapy don’t produce enough improvement, other injectable treatments can be considered. In a study of 120 patients comparing different injection therapies for resistant scars, bleomycin (a medication that inhibits cell growth) injected directly into the scar produced significant improvement on standardized scar scales and had zero relapses in the treatment group. By comparison, another injectable option showed relapse in 12 to 14 patients per group. The trade-off is that these more aggressive injections carry higher rates of side effects including pain at the injection site, temporary darkening of the skin, and occasional ulceration.
Surgical Revision
Surgery to remove a hypertrophic scar is generally reserved for cases where the scar is large, functionally limiting, or unresponsive to other treatments. The challenge with surgical excision is that cutting creates a new wound, which can produce a new hypertrophic scar. To reduce this risk, surgeons use techniques that minimize skin tension: specialized closure methods like Z-plasties, deep sutures that take pressure off the skin surface, and local tissue flaps.
Even with these precautions, recurrence is a real concern. One case series found that combining post-surgical steroid injections with six months of twice-daily corticosteroid ointment still resulted in a 16.7 percent recurrence rate for hypertrophic scars. This is why surgery is almost always paired with adjuvant therapy like silicone sheeting, steroid injections, or pressure garments starting soon after the wound heals.
Onion Extract Products
Over-the-counter scar gels containing onion extract are widely marketed. The evidence is modest. In a study of cesarean section scars, patches containing onion extract and allantoin showed statistically significant improvements in pigmentation, surface texture, and pliability when scored by clinicians. However, when patients rated their own scars, there was no significant difference between treated and untreated groups. Onion extract products are unlikely to cause harm, but they shouldn’t replace silicone or other better-supported treatments for a scar that’s actively thickening.
Prevention During Wound Healing
If you know you’re prone to raised scarring, or you have a wound in a high-risk area like the chest or shoulder, preventive measures can make a meaningful difference. The simplest intervention is paper tape applied across the healing wound for 12 weeks after sutures are removed. The tape reduces the stretching forces on the skin that stimulate excess collagen production.
Starting silicone sheeting as soon as the wound has fully closed (no scabs, no open areas) adds another layer of protection. For high-risk patients undergoing planned surgery, some providers begin preventive steroid injections at the time of wound closure. The goal with all of these approaches is the same: keep tension off the wound, keep the skin hydrated, and give the healing process the least reason to overshoot.