The invention relates to the use of hydrophilic aromatic alcohols to enhance the uptake of molecules, including biologically active macromolecules, into the body across the intestinal wall from the lumen of the gut; to compositions for oral administration which consists of an enteric capsule capable of withstanding transit through the stomach, containing a mixture comprising: (a) an active principal, and (b) a hydrophilic aromatic alcohol absorption enhancer; and to the user of the composition in medical treatment and diagnosis.