Why does pigmentation get darker after laser treatment?
In short
Darkening around 2–3 weeks after laser treatment is common and is called post-inflammatory hyperpigmentation. Inflammatory signals stimulate pigment cells to make more pigment, and depending on whether it sits in the epidermis or dermis, fading can take weeks to years.
Key points
- (1).
Substances like prostaglandin E2, interleukin-18 and -33, and interferon gamma increase pigment production, while interleukin-1 and -6 and TNF are reported to suppress it, which is one reason responses differ between people.
- (2).
Epidermal pigmentation looks light brown and fades over weeks to months, while dermal pigmentation, where pigment drops into the dermis, can last months to years and looks more gray or bluish.
- (3).
A 2024 systematic review of treatment outcomes found complete clearance in 18.1% with lasers and devices, 5.4% with topicals and 2.4% with combined approaches, none above 20%, and pigmentation worsened in 2.6% of laser or device treatments.
- (4).
However, most cases in that review were pigmentation after acne, so these numbers cannot be applied directly to pigmentation after laser.
- (5).
A 2022 review of 47 studies (1,853 people) found sunscreen (SPF 30 or higher) recommended in almost every study, and if common side effects of topicals like peeling, burning or stinging are strong, they can become new inflammation themselves.
When to see a doctor
See a dermatologist if it has not faded at all after 3 months, if the area is spreading, if there are blisters, oozing or pain, or if the color looks more gray or bluish than brown.
FAQ
How many days until it fades?
If the pigment is in the epidermis it takes weeks to months; in the dermis it can take months to years. Use 3 months as a checkpoint.
Can I have my next laser session while the pigmentation is still there?
Adding heat to skin that is still inflamed can make it darker. The timing should be decided by examining your skin directly.
Why do I seem to get it more easily than others?
The darker the skin tone, the stronger the pigment cell response. The skin types most Koreans have tend to react this way more than those of Western people. It is often constitution, not a care mistake.
REFERENCES
- Kaufman et al., Am J Clin Dermatol 2018 ↗
- Fu et al., Mol Med Rep 2020 ↗
- Kashetsky et al., J Eur Acad Dermatol Venereol 2024 ↗
- Tan et al., J Dermatolog Treat 2022 ↗
Written and reviewed by Dr. Kevin Kim, M.D.Last reviewed October 2026
Read the full post on Naver Blog (Korean) ↗