Thiophene derivatives of the formula ##STR1## WHEREIN R.sub.x is --S-CHR.sub.5 -COOH or -S-CH.sub.2 -CH.sub.2 -OH, R.sub.y is 1-2 of halogen alkoxy of 1-6 carbon atoms, aralkyl of 7-10 carbon atoms, phenyl, halophenyl or alkylcarbonyl of 1-6 carbon atoms in the alkyl group, and R.sub.5 is a hydrogen atom, when R.sub.y is a halogen atom, when R.sub.5 is alkyl, their enantiomers, and their pharmacologically acceptable salts thereof with bases, possess antilipolytic activity.