It is a prescription drug so you would need a private prescription for it in the UK, else a reputable online pharmacy will not supply it. Be wary of anywhere that offers Prescription Only medicines without wanting to see a prescription.
I would be extremely wary of buying pharmaceuticals from overseas, there are so many scams, fake and substandard drugs - some of which are nothing but harmless disguised chalk, but others may contain all sorts of things. They even take cheap medicines like paracetamol and repackage it. The packaging is often entirely convincing. Even if the drug is what it claims to be, it may not have been produced under safe conditions, may contain contaminants or in some way substandard
Be aware that nothing prevents your own NHS doctor from issuing a private prescription, although it's at their discretion. Some charge, some don't The standard fee is £15-20 for the prescription. On top of that, you would need to pay the full, unsubsidised, cost of the medication. However, from what I could gather, Donepezil is not a particularly expensive drug espescially in generic form.
You should also be aware that patients who are receiving private treament can be denied NHS funded treatment (excluding emergencies)
This is because the NHS is essentially an "all or nothing" deal. It was set up in such a way that all patients are treated as equal; having "wealthier" patients receiving NHS funded treatments and then being able to buy extra privileges is a violation of it's founding principles. What actually happens lies with the Primary Care Trust. However, it is much less likely, follwing a series of well publicised stories in the press a while back, concerning patients with terminal cancer who privately obtained life-extending, very expensive drugs not generally available via the NHS - because in many cases they extended life by at most a couple of months, at very high cost. This is of course a highly emotive issue but as the NHS doesn;t have limitless resources the position was understandable.
