Biological process

down regulation of nitric oxide biosynthetic process, down-regulation of nitric oxide biosynthetic process, downregulation of nitric oxide biosynthetic process, negative regulation of nitric oxide anabolism, negative regulation of nitric oxide biosynthesis, negative regulation of nitric oxide formation, negative regulation of nitric oxide synthesis

Any process that stops, prevents, or reduces the frequency, rate or extent of the chemical reactions and pathways resulting in the formation of nitric oxide.