Summary The aim of this work is to evaluate the predictable nature in human therapeutics of results obtained with some anti-seborrhoeic drugs in various experimental tests performed in vitro or in vivo on animal models. This correlative study applies to anti-seborrhoiec drugs (mainly of the hormonal type) for which the results of tests based on objective measurement criteria (secretion of sebum, synthesis of sebaceous lipids, height and mitoses number of sebaceous gland) are available in the animal as well as in man (literature references or assays performed in our laboratory). Natural or more often synthetic oestrogens are currently used in women with seborrhoea or acne, as an oral contraceptive drug and, more recently, as a local therapy in both sexes. Benefits of such utilisation have been well assessed by assays on animal models in which powerful oestrogen derivatives (ethinyl estradiol, diethylstilboestrol) are actually active by systemic administration on the sebaceous target as well as on the sexual organs. Nevertheless a more specific action on the sebaceous gland has been found for other less powerful estrogen derivatives (promestriene or CM 4727). The topic use may yet be criticised because the inhibition observed in the animal is usually a systemic one and, on the other hand, depending on the animal chosen and its sex, the results may not be in agreement with those described for human tests.