If you will be funding the treatment yourself you do NOT need to see your GP.
If you will be claiming through Private Medical Insurance, you will need to have seen your GP first.
We do not necessarily need to see a letter from your GP at your first visit if there is a time delay with this, as long as you have either seen your GP or had a verbal agreed referral, and as such confirmation be in your medical records. Once you have received your referral letter we will need to see it.