Melasma: Laser Toning or Picosecond Laser?

Split-face studies that directly compare laser toning (Q-switched 1064 nm Nd:YAG) with picosecond lasers for melasma mostly find no significant difference in how much pigment fades, though the studies disagree on which device hurts less during treatment, and recurrence rates look similar across both. Before choosing a device by its name, we recommend confirming first whether your pigment is melasma or a separate flat spot, and whether your schedule allows the multiple sessions these studies were built on.

Hello, I am Dr. Kim Yeon-jin, Chief Physician at UHCELL Clinic Gangnam. Patients researching melasma treatment in Korea usually ask us the same question first: is laser toning or a picosecond laser more effective. Today I want to walk through the split-face studies that compared the two approaches on the same patient’s face, and explain how to think about this if you are visiting Seoul for a short stay.

Laser Toning and Picosecond Lasers Differ in Pulse Duration

The real distinction between the two is how long the laser holds its light in a single pulse. What patients call “laser toning” is usually a Q-switched 1064 nm Nd:YAG laser, delivered in nanosecond pulses (one billionth of a second) at low energy across the whole face. A picosecond laser fires in picosecond pulses (one trillionth of a second), a much shorter burst. When a picosecond laser is delivered the same low-energy, whole-face way, it is called picosecond toning. So “toning” describes how the energy is delivered, while “Q-switched” and “picosecond” describe how long each pulse lasts.

There is a theoretical reason to expect a difference. Researchers who published a randomized, double-blind split-face trial in the Journal of Cosmetic Dermatology in 2026 explain that picosecond pulses may break pigment into smaller particles than nanosecond Q-switched pulses, and smaller particles may be cleared more easily by the body’s macrophages, which could lower the risk of post-inflammatory hyperpigmentation. That is a mechanism, not a measured outcome in melasma patients. For the actual result, we need the comparison studies below.

What the Split-Face Studies Found for Melasma

Each of the following studies treated one half of a patient’s face with a picosecond laser and the other half with a Q-switched laser, which reduces the effect of individual skin variation on the comparison.

Study	Design	Melasma improvement	Pain, safety, recurrence
Hong et al., Journal of Dermatological Treatment (2022)	20 Korean melasma patients. 1064 nm picosecond toning vs. 1064 nm Q-switched toning, 5 sessions 2 weeks apart	Both sides improved from baseline. No significant difference between devices at any time point	–
Feng and Huang, Plastic and Reconstructive Surgery (2023)	18 melasma patients. 1064 nm picosecond vs. 1064 nm Q-switched, 3-month follow-up	Both sides improved significantly. No significant difference between devices	Pain was greater on the Q-switched side. Recurrence was 12.5 percent on both sides
Zhou et al., Lasers in Surgery and Medicine (2024)	20 enrolled, 3 withdrew. 755 nm picosecond (diffractive lens array) vs. 1064 nm Q-switched, 3 sessions 1 month apart, 2-year follow-up	Only the Q-switched side showed a significant decrease from baseline at 6 months. No significant difference between the two sides	Pain was lower on the Q-switched side. No serious adverse events. At 2 years, 10 of 17 patients (58.82 percent) had recurrence or worsening, with no difference between devices
Researchers in Journal of Cosmetic Dermatology (2026)	Asian women with melasma. 1064 nm picosecond vs. 1064 nm Q-switched, double-blind	No significant difference in the degree of improvement	Pain immediately after the first session was lower on the picosecond side
Researchers in Lasers in Medical Science (2018)	12 Asian melasma patients. 755 nm picosecond vs. 1064 nm Q-switched, 4 sessions 1 month apart	At 3 months, pigment reduction was greater on the 755 nm picosecond side	The study authors concluded the 755 nm picosecond laser was a safe and effective option for melasma in Asian patients

In four of these five studies, melasma improvement was not statistically different between the two devices. The one study that favored picosecond lasers was the smaller 2018 trial of 12 patients. Most of these studies enrolled only 12 to 20 patients, and wavelength, energy, interval, and session count all varied between them. Based on this evidence, we cannot tell you that a picosecond laser clears melasma better than laser toning.

Pain and Recurrence Can Differ Even When Pigment Clearing Does Not

What patients actually feel during and after treatment can diverge even when the pigment result looks similar. Feng and Huang, working at the Plastic Surgery Hospital of the Chinese Academy of Medical Sciences and Peking Union Medical College, found less pain and less post-treatment redness on the picosecond side, with a possibly lower risk of melasma worsening. Zhou and colleagues found the opposite: less pain on the Q-switched side. Their picosecond device used a 755 nm diffractive lens array handpiece, which is a different wavelength and delivery system from the 1064 nm picosecond lasers in the other studies, so results under one “picosecond” label are not interchangeable. This is why, in a consultation, I weigh wavelength, energy setting, session interval, and how your skin responded to past treatments more heavily than the device name on its own.

Melasma and Flat Pigmented Spots Raise Different Questions

Every study above was conducted specifically in melasma patients. A flat, sharply bordered spot such as a solar lentigo or freckle is a different condition, and results from melasma trials do not transfer to it automatically. Because the same face can carry both melasma and flat spots at once, we diagnose each area before designing a treatment plan, rather than applying one protocol across the whole face.

Planning a Short Stay in Seoul

Every comparison study above measured its result after multiple sessions: Hong and colleagues used five sessions two weeks apart, Zhou and colleagues used three sessions a month apart, and the 2018 study used four sessions a month apart. If your stay in Seoul runs two to seven days, you will likely receive only one of those sessions during this visit. We treat that first visit as the start of a diagnosis and a treatment plan, and during the consultation we work out together whether the following sessions continue here in Seoul or with a clinician near you after you return home.

If your schedule includes significant sun exposure during your stay, tell us in advance. If pigment looks darker after treatment, or if pale spots appear, do not add home whitening products on your own; come in for an exam, since the treatment plan may need to change.

What to Tell Us Before Your Consultation

Photos are enough for most of this. Please have the following ready:

1. When the pigment first appeared, and whether it darkened with summer sun, pregnancy, or hormonal medication
2. The type, number of sessions, and interval of any previous toning, picosecond, or peeling treatments, and whether pigment darkened or pale spots appeared afterward
3. The names of any whitening products or medications you are currently using (a photo of the product or package works)
4. Your return date, any planned outdoor activities during your stay, and whether you can continue treatment near home afterward
5. A photo of your bare face, without makeup, taken in bright natural light

Our Gangnam Clinic

Our Gangnam location is on the 2nd and 3rd floors of the WD Building at Teheran-ro 8-gil 13, inside the UH FLAT SIGNATURE Gangnam hotel. Treatment takes place in a private room, and we have Japanese, Chinese, and English-speaking staff on site, so details like when your pigment first appeared or how you responded to past treatment can be explained in any of those languages.

If you are staying at UH FLAT SIGNATURE Gangnam, you can return to your room in the same building to rest after treatment. Guests of UHC hotels may choose one complimentary option between a 30-minute oxygen chamber session or an IV vitamin drip; if you use both, the IV vitamin drip is 55,000 won. Full conditions are posted on our promotion page.

FAQ

Will melasma come back after treatment?

Plan for the possibility of recurrence from the start. In Zhou and colleagues’ 2-year follow-up, 10 of 17 patients (58.82 percent) reported recurrence or worsening, with no difference between picosecond and Q-switched devices. Feng and Huang’s study, followed for 3 months, found a 12.5 percent recurrence rate on both sides. These two figures were measured over different follow-up periods, so they are not directly comparable. Discuss sun protection and a maintenance plan with us when you choose a device.

Which option hurts less?

Among 1064 nm devices, Feng and Huang’s study and the 2026 Journal of Cosmetic Dermatology trial both found less pain on the picosecond side. Zhou and colleagues, comparing a 755 nm picosecond device against Q-switched, found the Q-switched side was more comfortable. If you are sensitive to pain or had a difficult experience with a past treatment, tell us during the consultation; we factor that into the wavelength and setting we choose.

How do I know if my pigment is melasma or a flat spot like a freckle?

This requires an in-person or photo-based diagnosis, since the two conditions can look similar but respond differently to treatment. Bring clear, makeup-free photos in natural light so we can assess this before recommending a device.

If you are weighing which pigment to treat first, or how to fit a treatment plan into your stay, prepare the information above and book a consultation with our Gangnam clinic.

※ Individual skin response and recovery time vary. Please consult a specialist for an exact diagnosis and treatment plan.