US vs EU label comparison
Only the US label names the source
The US label states the botanical source. The EU leaflet uses an unqualified starch term, so on the EU label alone the source is undetermined.
US drug labelsas of April 2026EU drug labelsApril 2026 snapshot
FDA Structured Product Label, via DailyMed
EMA product information leaflet
This compares disclosure, not gluten content. A label that names maize starch has resolved the question. A label that says only “starch” has not — the starch may well be corn, and usually is, but the label does not say so, and that gap is the finding.
Nothing here says macitentan is or is not gluten-free. It says what each regulator's label states, which is the only claim this dataset supports. Brand and generic products of the same molecule can differ, and a manufacturer can reformulate without any announcement.
These labels were captured in April 2026. That is old enough to matter: check the current label for the product you actually have.
Gluten Screen is a label-reading tool, not medical advice, and is not a pharmacist, physician or dietitian. Never stop, switch or substitute a prescribed medication because of something you read here. Bring the question to your pharmacist or prescriber.