Trichozette

Walk around any beauty trade show and you will see red light glowing from helmets, caps, hoods and handheld wands. The category goes by several names: low-level light therapy, low-level laser therapy, photobiomodulation, or simply LED. The names matter less than the questions underneath them. What is the device meant to do, for whom, and how do we know?

The research, in outline

Low-level light has been studied mainly in pattern hair loss. A number of trials have reported modest changes in hair counts or density over several months of regular use. The research also has well-known limits. Many studies are small or short, devices and settings vary widely, and some trials are funded by the companies selling the equipment. Researchers are still discussing how the light might act on the follicle, and which wavelengths, doses and schedules matter.

A fair summary, then, is that low-level light may help some people with some types of hair loss, and that results are variable and depend on consistent use. That is a long way from the language of regrowth and guarantees that often surrounds it.

What that means in the treatment room

• Establish the likely cause of the hair loss first. Light will not address thyroid disease, iron deficiency, scarring conditions or medication effects, and some of those need a doctor.
• Set expectations in writing. Say that response varies, that any change is usually gradual, and that stopping treatment may mean losing what was gained.
• Photograph and measure at baseline and at agreed intervals, under the same lighting and from the same angles, so that you and the client can judge progress honestly.
• Follow the manufacturer's instructions on eye protection, contraindications and photosensitising medication, and record that you have checked.

Ultraviolet is not the same thing

Ultraviolet light is used in dermatology, under medical supervision, for certain inflammatory skin conditions, which can include some that affect the scalp. It is also a known cause of sunburn, skin ageing and skin cancer. The dose that helps one person can harm another, particularly someone with fair skin, a history of skin cancer, or medication that makes the skin more sensitive to light.

For that reason, ultraviolet treatment of the scalp is not something to offer on the strength of a supplier's training day. It needs a clear clinical reason, proper training, and medical oversight wherever a condition is being treated. If a device on your shortlist emits ultraviolet, ask exactly what it is for, who should be operating it, and what your insurer says.

Light-based devices can earn a place in a considered practice. They earn it through careful case selection, honest conversation and good records, not through the brochure.