We have seen rather mixed reports about dispensing "specials" - varying from someone sometimes getting the UK product, sometimes a special; being told specials cannot be prescribed; needing prescriber's involvement (e.g. endorsing the prescription in some way) or not; and so on.
The document below (obviously far more by following the link) might help to clarify what is allowed, when, who by, and so on.
One justification I have not seen in the bits I have read so far is that they might enable a patient to get a medicine which would otherwise be too expensive - an obvious case being our dear liothyronine (T3).
Professional Guidance for the Procurement and Supply of Specials December 2015
Specials are a category of unlicensed medicines that does not have either a centrally authorised Marketing Authorisation in the European Union, or a UK Marketing Authorisation and are manufactured, imported or distributed to meet the special clinical needs of an individual patient (see also Definitions).
A Special may only be supplied when there is no available licensed medicine which fully meets the patient’s special clinical needs. Specials can be prescribed when it is judged by the prescriber and agreed with the patient or carer that, on the basis of available information, a Special is the most appropriate option for the patient.
Whilst there are several other categories of unlicensed medicines, this professional guidance relates primarily to the procurement and supply of Specials. Other categories of medicines not directly in the scope of this guidance include:
Medicines used outside the terms of their Marketing Authorisation (commonly referred to as ‘off-label’ use);
Medicines rendered unlicensed when the dosage form is manipulated, for example, crushed tablets/opened capsules (see separate RPS guidance 3); and
Extemporaneously dispensed medicines prepared in a pharmacy.