Any process that decreases the frequency, rate or extent of the chemical reactions and pathways resulting in the formation of heme.
Synonyms:
exact_synonym:
down regulation of heme biosynthetic process; downregulation of heme biosynthetic process; negative regulation of haem biosynthetic process; negative regulation of heme anabolism; negative regulation of heme biosynthesis; negative regulation of heme formation; negative regulation of heme synthesis