Once you have a medical diagnosis, you are entitled to a reasonable quantity of essential* gluten-free foods on prescription.
These essential foods include:
Loaves and Rolls
Breakfast Cereals
Flour Mixes
Pasta
Pizza Bases
Crackers
Biscuits (biscuits are only prescribed in exceptional circumstances on clinical advice)
*The type and quantity of gluten-free foods allowed on prescription will depend on the NHS Clinical Commissioning Group (CCG) area you live in.