7-hydroxy-6-methyl-8-(1-D-ribityl)lumazine is the pteridine that is lumazine substituted with a methyl group at C-6, a hydroxy group at C-7 and a 1-D-ribityl group at N-8. It has a role as an EC 2.5.1.9 (riboflavin synthase) inhibitor. It is functionally related to a ribitol and a lumazine. It is a conjugate acid of a 7-hydroxy-6-methyl-8-(1-D-ribityl)lumazine(1-).