Madeleine Finlay

So this is the idea that shining red light on yourself is going to have some kind of health or aesthetic benefit.

So let's think about the electromagnetic spectrum.

Starting with UV, which is short wavelengths, then you go into the visible spectrum and you're going to have the short wavelengths of visible light.

That's blue and purple.

And then as the wavelengths get longer...

Think of the rainbow, you go yellow, orange, red.

So red has the longest wavelengths that we can see.

And after that, you go into infrared.

And those long wavelengths allow the light to penetrate our skin millimetres and perhaps even a few centimetres deep.

And so it's getting into our bodies and it's interacting with us in supposedly a beneficial way.

The concept behind what is sometimes called phototherapy or now photobiomodulation has actually been around for quite a long time.

This idea that shining different wavelengths of light could treat potentially different conditions.

And

There is some logic behind it.

You know, you think about how we make vitamin D, for example.

Light shines on us, we produce vitamin D. But look, for this research on red light therapy, I got in touch with Dr Jonathan Kentley.

He's a consultant dermatologist who works for the NHS and in a private practice.

And I asked him the same thing.

When did red light therapy begin to take off, really?

And like all the very best scientific discoveries, Ian, it happened by accident.