The achievement of increasing both the adsorption and release of heparin in a drug delivery system is reported. The reduced graphene oxide (rGO) material can efficiently adsorb heparin in aqueous solution up to 112 mg g⁻¹ owing to its layered and stacked structure. Moreover, this carbon vessel is able to release 90 mg g⁻¹ of the drug within 30 days, exhibiting the highest released/adsorbed ratio of 80% to date and has become a promising candidate as a novel drug releaser.