Unconjugated and conjugated bilirubin are molecules of physiological importance with increasing evidence demonstrating multipotent cardiovascular protective effects in conditions of benign hyperbilirubinemia. Individuals with Gilbert's Syndrome, a condition typified by benign hyperbilirubinemia resultant to impaired bilirubin conjugation, report reduced cardiovascular disease risk, increased serum antioxidant capacity, increased anti-inflammatory profiles and favourable lipid-profiles. Unconjugated bilirubin also possesses established antiplatelet characteristics, with reduced activation and aggregation reported at physiologically relevant concentrations. Despite previous works demonstrating that endogenous and synthetic bilirubin compounds possess antioxidant potential, the specific impact of these compounds on platelet function more globally is poorly understood. The main aims of this thesis were to assess whether bilirubin ditaurate, a synthetic water-soluble analogue of bilirubin diglucuronide, induces acute antiplatelet effects and, if so, could inclusion during platelet storage preserve platelet characteristics? This thesis also aimed to investigate if increased in vivo serum total bilirubin concentrations inhibit platelet activation in vivo, in efforts to establish if a widely available natural product could induce an Iatrogenic Gilbert's Syndrome. [...]