Abstract: Compositions and methods of increasing the bioavailability of catechins are presented. Compositions for increasing the bioavailability of catechins include compositions where the catechin is added to a solution of ethanol and water; compositions where the catechin is encapsulated within a nanoparticle; and compositions in which a nanoparticle complex is formed between the catechin and the nanoparticle. Each of these compositions was shown to increase bioavailability of EGCG and is useful in treating diseases such as Alzheimer's and HIV-associated dementia.