A pill printed with M231 is Atenolol 50 mg, a white, round, 7 mm tablet.
By the pharmaranks editorial team·Reviewed against the U.S. FDA / DailyMed (Structured Product Labeling) sources·How we research
The pictures are diagrams drawn from the shape, colour and imprint on the FDA label — not photographs of the actual tablet. Identify by the imprint, and confirm with a pharmacist.
A pill’s appearance varies between manufacturers and generic versions, imprints wear off, and two different drugs can share an imprint. Everything here is transcribed straight from the FDA’s DailyMed labels — we do not alter or infer it — but treat any identification as a starting point and confirm with a licensed pharmacist before taking or discarding a medication.
Source: the U.S. National Library of Medicine’s DailyMed Structured Product Labeling — the FDA-required drug labels. Imprint, colour, shape, size and score are transcribed, not inferred. This is reference information, not medical advice.