Dr Jonathan Kentley

subjective.

So there's no real measure of the amount of collagen that's going to be increased.

And obviously it's going to vary very much from mask to mask and person to person.

I don't think anyone has really decided what the parameters are.

And the parameters is when we think about how far away from the skin, how strong the energy is, and how long you use it for.

And if you look at the studies, the figures that they quote vary hugely.

So if you look at fluence, which really represents how strong the light is that's going into the skin,

That ranges in studies from 2 joules per centimetre to 120 joules per centimetre.

And some of these will be every day for 10 minutes, some will be three times a week.

So it's very difficult to compare like to like.

My general advice that I tend to give to people is if you have the money and you want to do something that may help, certainly feel free to invest in a mask, but don't go into it thinking that it's going to be...

a life-changing outcome that you're going to see in your skin.

Anyone who's telling you they're going to obliterate all your wrinkles with an at-home cream or an at-home device, really they're lying to you.