Thickening agents: what to consider when choosing a product?

This Medicines Q&A provides information on thickening agents and describes factors that may influence the choice of product including differences between starch-based and gum-based thickening agents, patient factors and product information.


  • Many people with dysphagia require liquids to be thickened in order to swallow them safely.
  • People with dysphagia must be assessed and reviewed by an appropriately trained healthcare professional (a speech and language therapist) who will recommend the appropriate fluid consistency and food texture for that individual.
  • Fluid thickness and texture are measured on the IDDSI scale. Thickening agents can be used to modify liquids to the appropriate IDDSI Level for the patient.
  • Thickening agents available in the UK are starch-based or xanthan gum-based. There are a number of differences between them.
  • This Medicines Q&A describes the differences between starch-based and gum-based thickening agents and factors to consider when choosing a product.
  • An appendix to this Q&A lists brands of thickening agents available and provides information on composition e.g. carbohydrate, sugar and sodium content. Additional information regarding suitability for patients with specific diet requirements (e.g. gluten-free, vegetarian) is included where available.
  • Many products are available to prescribe at NHS expense; choice may be restricted by local contract or formularies.

This Medicines Q&A complements two others: