Medical Treatments · Skin & Lasers · IN Eternity Clinic
Alexandrite Laser in Singapore
A 755 nm long-pulsed laser that targets brown pigment sitting in the upper skin, such as sun spots and freckles. It works well on the right spot, and it is not the right laser for every brown mark.
Written & medically reviewed by Dr Sin Yong · 8 October 2026
Quick answer
- A 755 nm long-pulsed laser that targets brown pigment sitting in the upper skin, such as sun spots and freckles. It works well on the right spot, and it is not the right laser for every brown mark.
- Used for: Sun Spots & Freckles.
- Performed by: Dr Sin Yong at IN Eternity Clinic, 9 Scotts Road, Pacific Plaza (beside Orchard MRT).
- Enquire: SkinRev Lab, CityLink Mall (City Hall MRT) passes enquiries to the clinic, or contact IN Eternity Clinic directly on +65 8815 3008.
- Suitability, number of sessions and pricing are decided at consultation; individual results vary.
The alexandrite laser emits light at 755 nanometres, a wavelength that melanin (skin pigment) absorbs strongly. In its long-pulsed form, each pulse lasts milliseconds rather than the billionths of a second used by Q-switched or picosecond lasers. For people searching for an alexandrite laser in Singapore, Dr Sin Yong performs this treatment at IN Eternity Clinic for flat, well-defined brown spots that sit in the epidermis, the outer layer of skin.
The typical candidate is someone with sun spots (solar lentigines) on the cheeks, temples, forehead or backs of the hands, or freckles that have darkened with years of tropical sun. Because Singapore's UV is high all year round, these spots are common from the late twenties onwards. The same 755 nm wavelength is also widely used for hair removal, but the settings, handpiece and technique for pigment are different.
How it works
The mechanism,
in plain English
The principle is selective photothermolysis: light passes through the skin and is absorbed mainly by the target, here the melanin packed into the cells of a sun spot. The longer millisecond pulse heats the pigmented cells relatively gently, and the treated spot usually turns darker or slightly grey within minutes. Over the next one to two weeks, the darkened layer forms a thin micro-crust that flakes away, taking the excess pigment with it.
Because 755 nm is so well absorbed by melanin, the same property that makes it effective on a dark spot also means the surrounding skin absorbs some energy, especially in tanned or darker skin. Skin cooling, small spot sizes and careful settings help protect the surface. The main risk in Asian skin is post-inflammatory hyperpigmentation (PIH), a temporary darkening where the skin was heated, which is why spot selection and aftercare matter as much as the laser itself.
“Not every brown patch is a sun spot: melasma, birthmarks and some growths look similar and need a different plan.”
— Dr Sin Yong, IN Eternity Clinic
- Energy / device
- 755 nm alexandrite laser, long-pulsed (millisecond) mode
- Target layer
- Melanin in the epidermis (outer skin layer)
- Typical session
- Usually well under an hour, depending on the number of spots
- Downtime
- Spots darken and form fine crusts that usually flake off in about one to two weeks
- Performed by
- Dr Sin Yong, IN Eternity Clinic
Is it right for you
Who it suits,
and who it does not
Alexandrite laser in Singapore is mostly used for adults with discrete, flat brown spots that a doctor has confirmed are sun spots or freckles, especially on fair to medium skin. People who can protect the treated area from sun for several weeks, and who are happy to look a little speckled while the crusts flake, are good candidates. It is also an option for scattered spots on the backs of the hands and forearms, where many people want to even out tone.
It is not a treatment for melasma, the hormonal, blotchy pigmentation common in Asian women, because heat can trigger it to darken; low-energy toning or picosecond approaches with a melasma plan are used instead. Deeper blue-grey pigment, such as Hori's naevus, needs a Q-switched or picosecond laser. Raised, changing or irregular spots should be examined before any laser, as laser should never be used on a lesion that might be a skin cancer. Treatment is usually deferred during a tan, in pregnancy, and with light-sensitising medicines, and people prone to marked darkening after injury need extra caution.
Non-invasive alternative at SkinRev Lab
Needleless SkinBooster — The Needleless SkinBooster at SkinRev delivers hydrating and brightening boosters without needles. It can help overall radiance and support a sun-protection routine, but it does not remove a defined sun spot the way a pigment laser can. Read more
What to expect
Consultation, session
and aftercare
At consultation, Dr Sin Yong examines each spot, often with magnification, to confirm what it is and how deep the pigment sits. He will discuss whether alexandrite is the right tool, or whether a picosecond, Q-switched or toning approach suits your pigment better. A test spot may be done first, especially if your skin is darker or tans easily. A course is usually planned at consultation, as some spots clear after one visit and others need repeat treatment.
On the day, you wear eye protection and each pulse feels like a quick, hot flick; cooling is used throughout. Treated spots turn darker straight away. Keep them clean and moisturised, do not pick the crusts, and use a broad-spectrum sunscreen and shade without fail. Avoid scrubs, exfoliating acids and retinoids on the area until the skin has settled. Any darkening that persists after the crusts fall is reviewed at follow-up.
Where this happens
Assessment and non-invasive care — SkinRev Lab, CityLink Mall #B1-28, 1 Raffles Link, Singapore 039393. Underground from City Hall MRT and Esplanade MRT; a short walk from Raffles Place, Marina Bay, Suntec and Bugis. Open daily 11am–8pm.
Medical treatment — IN Eternity Clinic, 9 Scotts Road, #12-01 Pacific Plaza, Singapore 228210, beside Orchard MRT (three stops from City Hall on the North-South line). Mon–Sat 11am–8pm, closed Sunday. Treatments are performed by Dr Sin Yong. WhatsApp +65 8815 3008.
Enquiries to SkinRev Lab about medical treatments are passed to IN Eternity Clinic, where Dr Sin Yong performs them.
What the research says
The evidence,
with sources
Reviews of laser treatment for pigmented lesions describe long-pulsed alexandrite among the lasers used for solar lentigines and freckles, alongside Q-switched and picosecond devices. A 2025 systematic review of clinical studies on solar lentigines concluded that lasers as a group appear more effective than other methods such as creams and cryotherapy, with mostly mild and short-lived side effects, while noting that post-inflammatory hyperpigmentation remains a consideration. In a pilot study of Korean adults, many patients treated with a long-pulsed alexandrite laser for facial pigmentation reported good or excellent improvement.
The evidence in Asian skin is not uniform, which is why careful selection matters. A small retrospective study of Chinese patients comparing four pigment lasers for freckles and lentigines found that the long-pulsed alexandrite group did not show significant improvement and had a higher rate of post-inflammatory hyperpigmentation than the other lasers studied. The authors suggested that long pulses with small spot sizes may lower risk. For this reason, alexandrite is one of several tools Dr Sin Yong chooses between, rather than a default for every brown spot.
References
- Polder KD, Landau JM, Vergilis-Kalner IJ, et al. Laser eradication of pigmented lesions: a review. Dermatol Surg. 2011;37(5):572-595.
- Mardani G, Nasiri MJ, Namazi N, et al. Treatment of solar lentigines: a systematic review of clinical trials. J Cosmet Dermatol. 2025;24(4):e70133.
- Lee YB, Shin JY, Cheon MS, et al. Photorejuvenation using long-pulsed alexandrite and long-pulsed neodymium:yttrium-aluminum-garnet lasers: a pilot study of clinical outcome and patients' satisfaction in Koreans. J Dermatol. 2012;39(5):425-429.
- Ho SG, Chan NP, Yeung CK, et al. A retrospective analysis of the management of freckles and lentigines using four different pigment lasers on Asian skin. J Cosmet Laser Ther. 2012;14(2):74-80.
Common questions
Your questions,
answered
How much does alexandrite laser in Singapore cost at IN Eternity Clinic?
The cost depends on how many spots are treated, their size and whether a repeat session is likely, so pricing is given at consultation at IN Eternity Clinic. Before you compare prices, it is worth confirming that the spots are actually sun spots or freckles, because a laser that suits one type of pigment can worsen another, such as melasma.
Is the alexandrite laser safe for Asian skin?
It can be used in Asian skin, but with care. The 755 nm wavelength is strongly absorbed by melanin, so darker or tanned skin absorbs more energy around the spot, raising the risk of temporary darkening called post-inflammatory hyperpigmentation. Careful settings, cooling, a test spot, strict sun protection and choosing the right spots lower that risk, but cannot remove it entirely. Some people are better suited to a picosecond or Q-switched laser.
How is it different from pico laser or laser toning?
They work on different time scales and depths. The long-pulsed alexandrite heats pigment over milliseconds and suits defined spots in the outer skin. Picosecond lasers shatter pigment with ultra-short pulses and can reach deeper pigment and tattoo ink. Laser toning uses low-energy 1064 nm pulses across the face to even out tone gradually. Dr Sin Yong chooses based on what the pigment is and how deep it sits.
How long is the downtime?
Treated spots usually darken within minutes and form thin crusts that flake away over about one to two weeks. Most people return to work the same day, though the spots look more noticeable before they clear. You can usually wear sunscreen and, once the skin is intact, light make-up. Picking the crusts raises the risk of marks, so let them fall off on their own.
Will my sun spots come back?
The treated pigment usually does not return in the same spot if it clears, but new sun spots can appear because the skin keeps receiving UV, and Singapore's sun is strong all year. Freckles in particular tend to darken again with sun exposure. Daily broad-spectrum sunscreen, shade and a hat are the most effective way to keep results, and occasional touch-ups may be needed.
Can the alexandrite laser treat melasma?
Generally no. Melasma is driven by hormones, heat and light, and the heat from a long-pulsed pigment laser can make it darker or trigger rebound pigmentation. Melasma is usually managed with sun protection, prescription creams, and gentle approaches such as low-energy laser toning or carefully set picosecond treatment. A doctor needs to confirm the diagnosis first, since melasma and sun spots often appear together.
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