Items benefiting from the relief: What is food?: Food and medicine: Medicated foods
The liability of a medicated food depends on whether the main purpose of eating the product is nutrition (in which case it is a zero-rated food), or the therapeutic effects of its medicinal ingredient (when it will be standard-rated as a medicine).
Most zero-rated medicated foods are complete diets designed to meet the special nutritional needs of people with particular medical conditions, to which medicinal substances (e.g. antibiotics) have been added. They are frequently administered in hospitals, or under medical supervision. Since they are designed to meet the patient’s nutritional needs as well as conveying the medicinal ingredient, these products are classed as food.
Medicated foods which are considered primarily medicines would not constitute a complete meal replacement, nor be taken to fulfil nutritional needs; the food element is there only to act as a palatable carrier for the administration of the medicinal component. Medicated pastilles (for sore throats etc), syrups and linctuses fall within this category.