They are safe to use but can be stripping, particularly on fine, thinner hair types. For the most part I’ve avoided them, besides in one formula where I think they’re a good addition.

I have fine, wavy hair, so I need to be very picky about what products I use to avoid weighing it down or causing build up.

It is also said to deliver 200 per cent thicker, fuller hair, when used with PROfiller+ Shampoo and Conditioner. The website claims it “gives fine, flat hair an instant thickening boost”, and ...