Long-pulsed Alexandrite laser 755nm treatment Singapore — Dr Sin Yong

Long-Pulsed Alexandrite Laser Singapore · 755 nm · Hair Removal · Freckles & Sun Spots · Dr Sin Yong

Alexandrite Laser Singapore — 755 nm, Long-Pulsed, Chosen by Skin Type

Dr Sin Yong · MBBS (NUS) · MRCS (Edin) · MSc Aesthetic Medicine (London) · MSc Practical Dermatology (Cardiff) · International KOL

The long-pulsed Alexandrite laser at 755 nm is strongly absorbed by melanin — the pigment in hair and in sun-induced spots. That absorption is its power and its caution: the right wavelength for one skin type is the wrong one for another. Here, the laser is chosen after your skin is examined, not before.

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755 nm

Alexandrite Wavelength

Long-Pulsed

Millisecond Domain

Melanin

Primary Target Chromophore

Phototype

Decides the Wavelength

The Principle

One Wavelength Does Not Fit All Skin

Every laser treatment is a negotiation between the target and the surrounding skin. At 755 nm, melanin absorbs strongly — which makes the Alexandrite effective on dark hair and discrete pigmented spots, and demands respect in deeper skin tones, where the epidermis itself carries more melanin. This is why the examination, and Fitzpatrick phototype, come before the machine.

The Approach

Alexandrite When It Fits, 1064 nm When It Does Not

For lighter-to-medium phototypes, the long-pulsed Alexandrite is a workhorse for laser hair removal and selected lentigines. For deeper phototypes, the longer 1064 nm Nd:YAG wavelength bypasses more epidermal melanin and is often the safer choice. You are matched to the wavelength — never the other way around.

Mechanism

How the Long-Pulsed Alexandrite Works

The 755 nm beam is delivered in millisecond pulses — long enough to heat a hair follicle through its melanin, matched to the follicle’s thermal relaxation time, while cooling protects the surface. In hair removal, only follicles in their active growth phase respond to any one pass, which is why hair reduction is inherently a staged process across growth cycles.

On pigmented lesions, the same melanin absorption lets discrete, well-defined spots — freckles, lentigines — take up energy selectively. Diffuse or hormonally driven pigment such as melasma is a different condition entirely and is deliberately not treated this way; heat can make melasma worse, and telling those diagnoses apart is the point of the assessment.

What the Alexandrite Laser Addresses

Laser Hair Removal

Dark terminal hair on lighter-to-medium skin — face, underarms, arms, legs, back. The 755 nm wavelength’s strong melanin absorption is well suited to this combination.

Freckles & Lentigines

Discrete, well-defined sun-induced spots that an examination has confirmed are benign. Selective melanin targeting lightens the spot while sparing surrounding skin.

Ingrown Hair & Folliculitis-Prone Areas

Where repeated shaving or waxing drives ingrown hairs and inflammation, reducing the follicle addresses the cause rather than the symptom.

The Wrong Candidates — Named Honestly

Melasma, tanned skin, and deeper phototypes on this wavelength. These are not refused because they cannot be helped — they are redirected to the right tool, usually 1064 nm or conservative pigment protocols.

Skin Tone Matching

Fitzpatrick phototype is assessed formally. Singapore skin spans III to V — the group where wavelength choice matters most.

Combination Plans

Hair removal and pigment work are sequenced with any other laser treatments so wavelengths and recovery do not collide.

“You are matched to the wavelength — never the other way around.”Dr Sin Yong

Key Facts

Long-Pulsed Alexandrite Laser Singapore — the Mechanism in Numbers

Wavelength

755 nm (Alexandrite crystal)

Pulse domain

Milliseconds — long-pulsed, matched to follicle thermal relaxation

Chromophore

Melanin — in hair shafts and pigmented lesions

Follicle depth

Terminal hair bulbs sit roughly 2–4.5 mm deep

Alternative

1064 nm Nd:YAG for deeper phototypes

Principle

Selective photothermolysis — heat the target, spare the surroundings

Reference: Anderson RR, Parrish JA. Selective photothermolysis: precise microsurgery by selective absorption of pulsed radiation. Science. 1983;220(4596):524-527.

The Treatment Process

Phototype & Lesion Assessment

Skin type grading, examination of the treatment area, and — for pigment — confirmation that each spot is a benign, laser-appropriate lesion. Anything atypical is referred, not lasered.

Patch Test Where Indicated

On borderline phototypes or reactive skin, a small test area confirms the response before committing the full area.

Treatment

Protective eyewear, surface cooling, and systematic passes at settings chosen for your skin and target. Sensation is often described as a quick snap with warmth.

Aftercare & Review

Strict sun protection afterwards — pigment recurrence and rebound are sun-driven. Response is reviewed and settings refined; hair reduction is staged across growth cycles by design.

Frequently Asked Questions — Long-Pulsed Alexandrite Laser Singapore

It depends on your skin tone and target. 755 nm Alexandrite absorbs melanin more strongly — effective for hair and spots on lighter-to-medium skin. 1064 nm Nd:YAG penetrates deeper with less epidermal melanin uptake — usually the safer choice for deeper skin tones. The examination decides.

For Fitzpatrick I to III it is generally well suited. For IV and above, settings become conservative or the wavelength changes to 1064 nm. This is exactly what the assessment and, where needed, a patch test are for.

Treated spots can lighten substantially, but sun exposure creates new ones — pigment is an ongoing negotiation with ultraviolet light, not a one-time erasure. Sun protection determines how long results hold.

Melasma is heat-sensitive and hormonally driven; aggressive melanin-targeted heat can make it worse. It is managed with its own conservative protocols — a different diagnosis deserves a different plan.

Poorly — the laser targets melanin, and fine vellus or grey hair carries little of it. You deserve to know that before starting, not after.

Hair grows in cycles and only actively growing follicles respond to each pass, so treatment is staged by biology. The realistic plan for your area and hair type is set out at consultation.

Alexandrite Laser Consultation — Dr Sin Yong

Start with a message, not an appointment. Describe your concern on WhatsApp and you will get a straightforward reply about whether an assessment makes sense, before you commit to coming in.

WhatsApp +65 8023 7170

This page is general information, not a diagnosis. Suitability for any treatment is decided at an in-person medical assessment.