Sulfasalazine-d4 is the deuterium labeled Sulfasalazine. Sulfasalazine (NSC 667219) is an anti-rheumatic agent for the research of rheumatoid arthritis and ulcerative colitis. Sulfasalazine can suppress NF-kappaB activity. Sulfasalazine is a type 1 ferroptosis inducer[1][2][3][4].