... > SECTION VI - PRODUCTS OF THE CHEMICAL OR ALLIED INDUSTRIES > CHAPTER 29 - ORGANIC CHEMICALS > XI. PROVITAMINS, VITAMINS AND HORMONES > 2937 Hormones, prostaglandins, thromboxanes and leukotrienes, natural or reproduced by synthesis; derivatives and structural analogues thereof, including chain modified polypeptides, used primarily as hormones > Steroidal hormones, their derivatives and structural analogues > Oestrogens and progestogens