White scars can regain pigment because, in most cases, the color-producing cells (melanocytes) are still there. They’re dormant, not dead. Research published in PLOS One found that hypopigmented scar tissue contains the same number of melanocytes as normally pigmented skin. The difference is activity: melanocytes in white scars have almost no dendrites (the arm-like extensions that deliver pigment to surrounding skin cells), while melanocytes in pigmented skin have several. The goal of every repigmentation treatment is to wake those sleeping cells back up.
Why Scars Lose Color
When skin heals after an injury, the new tissue prioritizes structural repair over cosmetic function. Collagen fills the wound, but the melanocytes that survived the injury often shut down. In biopsies of white burn scars, inactive melanocytes averaged about 0.5 dendrites per cell, compared to 3.35 dendrites per cell in pigmented areas of the same patient’s skin. Dendrites act like delivery routes for melanin, so fewer dendrites means almost no pigment reaches the surface. This is why a scar can look completely white even though the pigment-producing machinery is technically present.
The thickness and depth of the original wound matter too. Superficial scars from minor cuts or abrasions often repigment on their own over months to years, especially with regular sun exposure. Deeper scars from burns, surgery, or severe acne are more likely to stay white because the damage to the skin’s deeper layers disrupts the signaling environment melanocytes need to stay active.
Excimer Laser Treatment
The 308 nm excimer laser is one of the most studied tools for scar repigmentation. It delivers concentrated ultraviolet light directly to the white scar, stimulating dormant melanocytes without exposing surrounding skin. In a clinical study, patients achieved roughly 60 to 70 percent pigment correction by visual assessment after nine biweekly sessions. Colorimetric measurements (which detect pigment the eye might miss) showed the treated scars actually reached about 100 percent of the surrounding skin’s pigment level.
Sessions are quick, typically lasting a few minutes, and the laser is well tolerated. Most protocols call for treatments twice a week. The scar may pink up temporarily after each session, similar to a mild sunburn. Results tend to appear gradually, with noticeable improvement usually visible after the fourth or fifth treatment.
Fractional Lasers Combined With Topicals
Fractional lasers work differently from the excimer. Instead of stimulating melanocytes with UV light, they create thousands of microscopic channels in the scar tissue. This serves two purposes: it triggers the skin’s wound-healing response (which can remodel scar collagen and improve texture) and it allows topical treatments to penetrate far deeper than they normally would.
A growing body of research pairs fractional CO2 laser sessions with prostaglandin analog solutions applied immediately after. In placebo-controlled trials, 11 out of 14 patients treated with fractional CO2 laser plus a prostaglandin analog achieved more than 50 percent improvement in scar color, with significantly higher satisfaction scores than patients who received the laser alone. The prostaglandin analog appears to directly stimulate melanocyte activity, and the laser channels give it a direct path to reach those cells.
Between fractional CO2 and erbium YAG lasers, CO2 tends to produce more dramatic results. In a split-face comparison trial, 92 percent of patients preferred continuing with CO2 over erbium YAG. However, CO2 lasers carry a higher risk of prolonged redness and pigment changes, particularly for people with darker skin tones. Erbium YAG causes less thermal damage and is often the safer choice for darker complexions.
Narrowband UVB Phototherapy
Narrowband UVB is the same light therapy used for vitiligo, and it works on white scars through a similar mechanism: repeated UV exposure coaxes melanocytes into producing pigment again. Treatment protocols typically start at a dose of 200 millijoules per square centimeter, increasing by 50 millijoules at each visit until the skin shows mild pinkness that fades within 24 hours. Sessions happen two to three times per week.
This approach is slower than excimer laser and less targeted, since it exposes a broader area of skin. It’s most practical for people with large or widespread white scars where treating each one individually with an excimer laser would be time-consuming. Home UVB units exist, though they require careful dose management to avoid burns.
Microneedling for Scar Repigmentation
Microneedling creates controlled micro-injuries in scar tissue using a device studded with fine needles (typically 1.5 mm depth for scars). This triggers a healing cascade that can remodel collagen and, importantly, stimulate melanocyte activity. The procedure is sometimes combined with topical agents applied immediately after needling, when absorption is highest.
In a comparative study using microneedling combined with a topical solution on depigmented patches, 48.6 percent of treated areas achieved excellent repigmentation (greater than 75 percent color return) after six months of biweekly sessions. Another 37.5 percent achieved 50 to 75 percent repigmentation. By comparison, microneedling alone produced excellent results in only 16.9 percent of patches. The combination approach clearly outperforms needling on its own, though even standalone microneedling can produce meaningful improvement over several months.
Melanocyte Transplantation
For scars that don’t respond to less invasive methods, melanocyte-keratinocyte transplantation is a surgical option. A small sample of normally pigmented skin is harvested (usually from a hidden area like the inner thigh), processed into a cell suspension, and applied to the scar after the surface has been prepared with a laser or dermabrasion.
In a study of 20 patients who underwent this procedure, 75 percent achieved a satisfactory result, defined as more than 50 percent repigmentation. Within that group, 25 percent achieved excellent results (90 percent or greater repigmentation) and 50 percent achieved good results (50 to 89 percent). Ten percent had poor outcomes with less than 20 percent color return. This technique is most commonly used for stable, well-healed scars and is performed by dermatologic surgeons with specialized training.
How Skin Tone Affects Your Options
Repigmentation treatments work across all skin tones, but the risk-benefit calculation shifts depending on your complexion. People with darker skin (Fitzpatrick types IV through VI) face a higher risk of post-inflammatory hyperpigmentation from aggressive laser treatments, meaning the scar could overcorrect and end up darker than the surrounding skin. Fractional CO2 lasers, while effective, carry this risk more than erbium YAG lasers for darker complexions.
Research on wound healing and pigment correction has historically been conducted primarily on lighter skin, leaving fewer evidence-based protocols for people with deeper skin tones. A stepwise approach is generally recommended: starting with gentler treatments and escalating only if needed. For darker skin, erbium YAG lasers, microneedling, and narrowband UVB tend to offer a better safety profile than aggressive CO2 resurfacing.
What Realistic Results Look Like
Complete, perfect color matching is uncommon with any single treatment. Most people achieve partial repigmentation that makes the scar significantly less noticeable without making it invisible. The best outcomes typically come from combining approaches: fractional laser to remodel the scar’s texture and create absorption channels, followed by a topical agent to stimulate melanocytes, with excimer laser or UVB sessions layered in to provide ongoing UV stimulation.
Timelines vary. Excimer laser can show visible results in four to six weeks with biweekly sessions. Microneedling protocols typically run four to six months. Melanocyte transplantation can produce results in two to three months after the procedure, though final color stabilization takes longer. Regardless of method, the repigmented color may fade somewhat over time without maintenance, since the melanocytes in scar tissue tend to be less robustly active than those in undamaged skin. Periodic maintenance sessions, whether with UV therapy or microneedling, can help sustain results.