Pharmacists are trained experts in the use of medicines. They can advise you on the safe use of prescription and over-the-counter medicines. Lots of pharmacies are open until late and at weekends. Many medications can be purchased cheaply over-the-counter, and in doing so you get a fast service and often can avoid the wait and time required to attend an appointment at the surgery. (If the pharmacist thinks that you need to see the GP or Practice Nurse about your problem then they will advise you.) If you are unable to pay for over the counter medicines you may be able to access free treatment for minor ailments see here.
Many pharmacies offer extra services such as blood pressure checking, help to stop smoking see here, medication review, emergency contraception see here, emergency supply of prescription medication, disposal of unwanted medicines.
Several pharmacies hold specialist medication for example medicines needed for palliative care. A list of these pharmacies can be found here.
The medication they hold can be found here.