Would you be able to recommend the best online delivery by post pharmacy for an autistic person in the United Kingdom of Great Britain and Northern Ireland?

Boots pharmacy maybe?  Depends on what you want and where you are though. 

From their website: "*Please note the repeat prescription home delivery service is only available to patients registered with a GP in England. However, the option to collect in store is available for all customers registered with a participating GP anywhere in the UK."

Have used Boots myself for ordering various things over the years, never had them fulfil a prescription though so I can't comment on that.

Boots pharmacy maybe?  Depends on what you want and where you are though. 

From their website: "*Please note the repeat prescription home delivery service is only available to patients registered with a GP in England. However, the option to collect in store is available for all customers registered with a participating GP anywhere in the UK."

Have used Boots myself for ordering various things over the years, never had them fulfil a prescription though so I can't comment on that.