MERCK & CO INC revenue for the last year amounted to 1.02 T MXN, the most of which — 910.11 B MXN — came from its highest performing source at the moment, Pharmaceutical, the year earlier bringing 1.01 T MXN. The greatest contribution to the revenue figure was made by United States — last year it brought MERCK & CO INC 483.74 B MXN, and the year before that — 530.64 B MXN.