When not to switch

For most medicines, one company's tablet and another's behave the same in your body. That is what the standard guarantees.

A small number of medicines have a narrow window between too little and too much — some thyroid and epilepsy medicines, some blood thinners. For these, doctors often prefer you stay with one maker so the dose stays steady. Your doctor may also write "do not substitute" for a reason of their own.

• If your doctor wrote "do not substitute", we do not.
• If a medicine is one of the narrow-window kind, our pharmacist will say so before you order.
• If you are unsure, ask. It is free and there is no obligation.

Never change a medicine without telling the doctor who prescribed it. We are a pharmacy, not a substitute for them.