What narrowband UVB is
Narrowband UVB is a focused band of ultraviolet light used to treat several skin conditions. Here is what the light is, what it is used for, and where the evidence stops.
Last updated 2026-07-29
What the light actually is
Narrowband UVB is ultraviolet light limited to a narrow band peaking around 311–313 nanometres — a small slice of the wider UVB range that sunlight also contains.[1]
What is known
Therapeutic narrowband UVB lamps are built to emit most of their energy in this narrow band rather than across the whole UVB spectrum. That band was chosen because it is the part of UVB most useful for treating skin, while leaving out much of the shorter-wavelength light that mainly causes burning.
What is uncertain
The precise peak differs slightly between lamps and manufacturers. Knowing the wavelength tells you what the device is; it does not tell you how much light any individual should receive, which depends on the person and is decided in a clinical setting.
What to ask
- Is the unit being discussed actually narrowband UVB, or a broadband or blue-light device?Saving keeps this on your device and needs JavaScript, which is off in this browser.
- How is the output of this particular lamp checked over time?Saving keeps this on your device and needs JavaScript, which is off in this browser.
What it is used for
Narrowband UVB is used as a treatment for several skin conditions, including vitiligo and psoriasis.[1][2]
What is known
It is an established option that dermatologists reach for across a range of conditions. On this site the app currently supports vitiligo; psoriasis education is here because the light is the same, even though the app does not track psoriasis yet.
What is uncertain
That a therapy is used for a condition is not a guarantee it will help a particular person, and it says nothing about how it compares to creams, oral medication, or newer drugs for that condition. Whether it is a good fit for you is a decision for you and a clinician, not for a website.
What to ask
- For my condition, where does phototherapy sit relative to the other options?Saving keeps this on your device and needs JavaScript, which is off in this browser.
- What would make me a poor candidate for it?Saving keeps this on your device and needs JavaScript, which is off in this browser.
Sources
British Association of Dermatologists and British Photodermatology Group guidelines for narrowband ultraviolet B phototherapy 2022
British Journal of Dermatology (Goulden V, et al.)
Regulatory / guidelineIndependent
- Published
- 2022-09-01
- Last checked by us
- 2026-07-29
Read the sourceWhat this source does and does not support
Supports that therapeutic narrowband UVB lamps have an emission spectrum peaking near 311–313 nm, and that this narrow band was selected because it is the most effective part of the UVB spectrum for treating psoriasis. It is a clinical guideline for clinicians administering phototherapy; it does not establish any home-use dose, and this site never reproduces its dosing schedules.
Phototherapy — NB-UVB (patient information leaflet)
British Association of Dermatologists
Patient educationIndependent
- Published
- 2022-06-01
- Last checked by us
- 2026-07-29
Read the sourceWhat this source does and does not support
Supports, in plain patient-facing language, that narrowband UVB uses a small part of the UVB spectrum and is used for skin conditions including psoriasis, eczema and vitiligo. As patient-education material it is context, not primary evidence, for any efficacy claim. Its review date is June 2025, so re-verify before relying on it past then.