Thulium 1927nm laser for the face: What it Actually Does, and Who I Turn Away
September 2026
Written by Dr Geeta Moor, MBBS MRCP FRCA MD(Res) — Medical Director, The Selborne Clinic
I have spent more than twenty years in the NHS as a doctor. The job trains you to understand that the most important part of any procedure is the conversation you have before it.
That instinct, and the need to make women and men feel confident about their skin, is the reason The Selborne Clinic exists in the form it does. It is also why I want to write about the 1927nm thulium laser. It is the device I use most on the face and it is the one patients ask about most.
What the wavelength actually does
LASER is an acronym: Light Amplification by Stimulated Emission of Radiation. Which is not especially helpful! In practice, a laser is a device that produces a narrow, focused, and coherent beam of intense light. That beam of light has a wavelength and each wavelength is chosen because of what absorbs it.
At 1927nm, the target is water. Water absorption at this wavelength is high — considerably higher than at 1550nm, the older workhorse of fractional resurfacing — which means the energy is absorbed fast and shallow. It does not travel deep into the dermis. It deposits its heat in the epidermis and the very uppermost dermis, roughly the top 200 microns of your skin. That is not a limitation. It is, in fact, the entire point!
The epidermis is where the pigment lives. It is where the sun damage, the freckling, the dull uneven tone, the rough patches and the enlarged-looking pores are. If your complaint is "my skin looks tired and blotchy", the problem is almost certainly sitting in the first fraction of a millimetre. Sending energy deep would be missing the target and buying yourself downtime you don't need.
The laser is also fractional. Rather than treating the whole surface at once, it delivers thousands of microscopic columns of thermal injury — microthermal treatment zones — surrounded by untreated skin. That untreated skin is your reservoir of healthy cells, and it is what makes recovery days rather than weeks. Recent imaging work using optical coherence tomography has shown that the effect at 1927nm sits on a spectrum from genuinely non-ablative to frankly ablative depending on the pulse energy and the tip used, which is exactly why settings matter and why "a thulium facial" is not one standardised thing.
