Amazing. I developed an allergy to other brands such as GDI as can happen if you use it regularly. I was dissapointed thinking I'd never be able to wear gel nails again. However I researched and found you can get 3 and 7 free varnishes containing less chemical. One of which is shellac cnd. I tried this and yes it works I get no reaction just beautiful nails. I have to use cnd top and. Base coat and colour and then I am fine. Deffo worth a try if you have an allergy like me. I just wish it wasn't so expensive!