Biliverdin dihydrochloride is a tetrapyrrolic pigment resulting from the degradation of heme. Heme is broken down by heme oxygenase into biliverdin, carbon monoxide, and iron. Subsequently, biliverdin is rapidly converted to bilirubin by biliverdin reductase. Biliverdin dihydrochloride exhibits antimutagenic, antioxidant, anti-inflammatory, and immunosuppressive properties.