The invention relates to a method for producing hyperbranched amylopectin having a mean molecular weight ranging between 2,000 and 29,000 Dalton and an average degree of branching of more than 10 percent and less than 20 percent, said degree of branching being expressed in mole percent of the anhydroglucose units carrying branching points. According to the inventive method, the molecular weight of plant amylopectins or starch rich in amylopectin is reduced to molecular weights not exceeding 60,000 Dalton by means of a-amylase or acid hydrolysis in a first hydrolysis step, and the molecular weight of the reduced product obtained in the first hydrolysis step is further reduced by means of .beta.-amylase reduction in a second hydrolysis step. The invention further relates to the production of coupling products of the hyperbranched amylopectin with a pharmaceutical agent.