LED facial masks. Never has one so expensive item become so popular so quickly. I am grumpy to a fault about most facial gadgets but regarding these at least, I can answer the hundreds of questions I get with (almost) unalloyed positivity.

In my experience, the most sceptical dermatologists are broadly positive about them. It’s easy to see why, because LED therapy is already used widely in doctors’ surgeries. At-home devices are weaker than doctors’ models, which clinical trials are usually based on, but the principles are the same and there’s evidence to support doing it yourself.

Red light has a longer wavelength and deals with the skin’s deeper layers, triggering pathways to repairing damage and inflammation, and stimulating fibroblasts, which produce collagen, so it’s used mostly for its anti-ageing benefits.

Blue light (short wavelength) has antibacterial and inflammation-reducing benefits and is used mainly on the superficial effects of acne.

Both are very safe (including in pregnancy) and cause no discomfort, skin trauma, scarring or damage, and can even prove effective on stubborn conditions like rosacea. However, any light-based treatment can be problematic for those with epilepsy or migraines, and the blue light settings are best avoided by sufferers of hyperpigmentation, since blue light is thought to stimulate melanin production (red light is fine).

Red light masks are all the rage because, when effective, they’re believed to tighten, smooth and plump skin. Some clinical trials show denser, more elastic skin as a result of long-term, diligent use. They are idiot-proof – the treatment is so passive it feels as though nothing is happening at all.

I’ve owned an LED mask (Dr Dennis Gross’s SpectraLite) for seven years but use it infrequently – not because it doesn’t work but because, as with lash serum, hair supplements and facial massage, it requires commitment that I am unable to offer.

But if you have the substantial disposable income and will to persevere, LED masks are good. As ever, though, none of these gadgets is worth the requisite time or money if you’re not already taking proper care of your skin by cleansing twice a day, keeping it hydrated with humectant skincare, protecting with sunscreen and not abusing it by smoking or excessive drinking. An LED mask or any gadget, however well evidenced, will at best complement, but can never be a substitute for, the basics.

Hair and makeup: Sarah Cherry. Model: Emily I at Nevs. Mask: Dr Dennis Gross DRx SpectraLite