Q-Switched Laser
Q-Switched Laser treatment uses high-intensity laser pulses at specific wavelengths to precisely target pigmented lesions in the skin.
Q-switched laser, explained
Q-switching is a method of compressing laser energy into an extremely short pulse — in the nanosecond range, a billionth of a second. It was the standard approach to pigment and tattoo removal for decades, and the term is still widely used.
The reason the distinction matters is not marketing. Pulse duration changes how the energy behaves in tissue, and that changes the risk profile — particularly on the skin types most of our patients have.
Key points
- Pulse duration Nanoseconds (10⁻⁹ s)
- Dominant effect Photothermal — pigment is heated until it fragments
- Common wavelengths 1064 nm · 532 nm · 694 nm · 755 nm
- Typical uses Tattoo ink, deeper pigment, some vascular lesions
- Offered here No — see picosecond alternatives below
Where the term comes from
“Q” refers to the quality factor of the laser cavity. Holding the cavity in a low-Q state lets energy accumulate, then releasing it suddenly produces a single very high-powered pulse. That engineering trick is what made pigment-selective treatment practical in the first place.
Why people still search for it
For many patients “Q-switched” is simply the phrase they learned for pigment laser treatment, the way people say Q-tip for a cotton swab. Often the question underneath is not about Q-switching at all — it is about whether a laser can treat their particular spots without leaving them darker afterwards.
Q-switched versus picosecond
Both target melanin and ink. The difference is how long the energy is delivered for, and that changes the dominant mechanism.
| Q-switched (nanosecond) | Picosecond | |
|---|---|---|
| Pulse duration | Roughly 5–20 nanoseconds | Roughly 300–900 picoseconds — about 1,000× shorter |
| Dominant mechanism | Photothermal: pigment absorbs energy, heats, fragments | Photoacoustic: pressure wave shatters pigment with less heat |
| Heat into surrounding skin | More | Less |
| Fragment size | Larger particles | Finer particles, generally easier to clear |
| Relevance to darker skin | More thermal loading, so a higher risk of post-inflammatory hyperpigmentation | Less thermal loading at comparable settings |
What that means in practice
Less heat is not automatically better. Some deeper or stubborn ink still responds well to a nanosecond pulse, and a picosecond device is not a universal upgrade. But on Fitzpatrick III–V skin — which is most of this clinic’s work — the main complication to avoid is post-inflammatory hyperpigmentation, and that risk tracks with thermal loading. That is the reason for the platforms we chose.
What has not changed
Neither technology removes pigment in one session, and neither prevents it from returning if the underlying cause is untreated. Melasma in particular is a chronic condition, and any laser is one part of managing it rather than a cure.
The platforms in this clinic
- PicoSure Pro— 755 nm picosecond, the main pigment platform here, including work on darker skin types.
- PicoWay— multi-wavelength picosecond (1064 / 785 / 532 nm), which widens what can be targeted, including multi-coloured tattoo ink.
Which one suits a given problem is decided at assessment, not from a menu. The overview of how pigment is diagnosed and matched to a device is on the pigmentation laser page.
If a Q-switched laser is genuinely the right answer
There are cases — certain tattoo inks and depths in particular — where a nanosecond device is a reasonable or better choice. We do not have one, and we will say so at consultation rather than substitute a platform that does not suit the problem.
What people usually mean when they ask
- “Is Q-switched better than pico?”Neither is universally better. They differ in pulse duration and therefore in heat, fragment size and risk profile.
- “Will it work on our melasma?”Melasma is chronic and easily aggravated by heat. It needs a plan, not a device choice — and sometimes the answer is not a laser at all.
- “Can it remove our tattoo in one go?”No. Multiple sessions are required regardless of the platform, and colour, depth and ink chemistry all affect the count.
- “Is it safe on our skin tone?”Risk on darker skin is managed by settings, test patching and sun protection — not by the brand of laser. Post-inflammatory hyperpigmentation is the complication to plan around.
Risks that apply to any pigment laser
- Post-inflammatory hyperpigmentation— the main risk on Fitzpatrick III–V skin. Usually temporary, sometimes months to resolve.
- Hypopigmentation— loss of pigment, which can be persistent. Uncommon.
- Blistering, crusting and textural change, particularly at higher settings or on recently sun-exposed skin.
- Incomplete clearance— some pigment and some ink colours do not fully resolve with any platform.
- Recurrence— where the underlying driver is hormonal or sun-related and is not addressed.
This page is general information about laser technology. It is not medical advice, it is not an offer of Q-switched laser treatment, and it does not replace a consultation.
Where the medical claims on this page come from
Everything above about Q-Switched Laser rests on published evidence rather than on our own word. The sources below are the ones behind those statements: peer-reviewed papers indexed in PubMed, and guidance written for patients by dermatology academies and national health services. Read them before you decide — and bring any of them to your consultation.
- Peer-reviewedA Systematic Review of Picosecond Laser in Dermatology: Evidence and Recommendations
- Peer-reviewedRecognizing and Managing Complications in Laser Resurfacing, Chemical Peels, and Dermabrasion
- Peer-reviewedCommon Dermatologic Procedures and the Associated Complications Unique to Skin of Color
- Peer-reviewedTreatment of Post-Inflammatory Hyperpigmentation in Skin of Colour: A Systematic Review
- Patient guidanceAcne: Lasers and lights
- Patient guidanceLaser tattoo removal
What these references can and cannot tell you. They describe what is known about the treatment itself — how well it tends to work, how long results last, and what can go wrong. They are not an assessment of this clinic, and no published study can tell you whether it suits your skin type, anatomy, or medical history. That judgement comes from the physician who examines you in person, and it may well be “not this one”.