A tablet has no ingredient list on the back. It has a leaflet, long, which nobody reads to the end. And among the excipients, the substances with no therapeutic effect that give the medicine its shape, cohesion and dissolution, sometimes appears wheat starch. The question is legitimate, and the answer more reassuring than feared, provided you know where to look.

Why there is starch in a tablet

An active ingredient is dosed in milligrams, sometimes micrograms. To make it into a tablet you can hold, swallow and that dissolves in the right place, it has to be combined with excipients: a diluent for bulk, a binder to hold it together, a disintegrant to make it break up in the stomach. Starch often plays all three roles. It comes from corn, potato, rice, or wheat.

Lactose is the other common excipient; it has nothing to do with gluten, but it explains why leaflets have a section devoted to ingredients “with known effect”.

What the leaflet must say

The European Medicines Agency keeps a list of excipients with known effect, with the sentence the leaflet must carry for each. Wheat starch is on it. The leaflet of a medicine containing it must state, in substance:

This medicine contains wheat starch. It contains only very low levels of gluten and is considered “gluten-free” [in the sense of regulatory thresholds], and is very unlikely to cause problems if you have celiac disease. If you have a wheat allergy, you should not take this medicine.

The reasoning behind that sentence: pharmaceutical-grade wheat starch must comply with the European Pharmacopoeia, which sets a very low limit on its total protein content. Combined with the amounts of starch in a tablet, a few tens of milligrams, the gluten per dose is counted in micrograms, well below what a day of “gluten-free” food at 20 ppm provides (we explain that threshold).

The distinction from wheat allergy is clear, and it is the same as for food: an allergy reacts to tiny protein traces, celiac disease to cumulative amounts of gluten. The leaflet rules differently for the two; we explain why.

Celiac disease

Considered suitable

  • Reacts to cumulative amounts of gluten
  • Gluten per dose counted in micrograms
  • Well below a day of food at 20 ppm

Wheat allergy

Do not take it

  • Reacts to tiny protein traces
  • The leaflet is categorical
  • Another presentation is needed

Where to look, concretely

  1. The leaflet, section “What [medicine] contains”: the list of excipients. Then the section “Important information about some of the ingredients” or “[Medicine] contains…”, where the standard sentence appears.
  2. The public medicines database of your country (the MHRA in the UK, the ANSM in France), which gives each product’s full composition.
  3. The pharmacist, who has access to the composition and knows whether an equivalent generic or presentation without wheat starch exists, which is frequent, since two manufacturers of the same active ingredient do not choose the same excipients.

If wheat starch is not mentioned anywhere, the medicine does not contain it: the information duty exists precisely for that.

What you decide

Patient associations do not ask people to avoid medicines containing wheat starch, and a necessary treatment is not questioned over an excipient. What can be discussed, with the pharmacist or doctor:

  • Long-term treatment, taken every day for years: asking whether an alternative without wheat starch exists is reasonable, if only to remove doubt.
  • An unexplained reaction despite a strict diet: listing medicines and supplements is part of the investigation, even if the medicine is rarely the culprit.
  • A confirmed wheat allergy: the leaflet is categorical, another presentation is needed.

Food supplements are a separate case. They come under food regulation, not medicines: allergens must be declared as on a yoghurt, but no standard sentence guarantees pharmaceutical quality. Brewer’s yeast, cereal extracts, wheat fibre and wheat germ are frequent in them. Read the label as you would a food’s.

In short

  • Some tablets contain wheat starch as an excipient; the leaflet must say so.
  • That starch is pharmaceutical grade; the gluten per dose is tiny, and the European Medicines Agency considers it compatible with celiac disease.
  • People allergic to wheat must avoid it: a different condition.
  • For daily treatment, an alternative without wheat starch often exists: ask the pharmacist.
  • Food supplements are read like foods.

This information is no substitute for medical advice. Never stop or replace a treatment over an excipient question without talking to your pharmacist or doctor.