Summary An assay was devised in which the hypocholesterolemic action of parenterally administered androsterone could be demonstrated in rats given a low dose of propyl-thiouracil. Using this procedure an analogue of androsterone, 3α-methoxy-17α-methyl-5α-androstan-17-ol (SC-12790), was found to have an oral hypocholesterolemic activity similar to that of parenterally administered androsterone. Endocrine assays indicated the new steroid to be a weak androgen of the same order of potency as androsterone. We gratefully acknowledge the assistance of Mr. R. S. Jacobs in performing the lipid studies, of Dr. E. F. Nutting in the endocrine assays and of Dr. D. L. Cook in carrying out the cardiovascular tests.