Dienogest

As a new generation of synthetic progestogen drugs, dienogest has high selectivity for the progesterone receptor, and has no estrogen, androgen or glucocorticoid activity. It can reduce the estrogen level by inhibiting the hypothalamic-pituitary-gonadal axis, and directly act on endometrial lesions to inhibit their proliferation. In clinical practice, it is mainly used for the treatment of endometriosis, which can effectively relieve dysmenorrhea, pelvic pain and other symptoms for a long time and reduce the volume of lesions. It is currently the first-line drug for the long-term management of endometriosis, suitable for patients of childbearing age and perimenopausal period, and can also be used in combination with estrogen for perimenopausal hormone replacement therapy.

The global market size related to dienogest had exceeded USD 2.1 billion in 2023, with a compound annual growth rate maintained at around 8%. The growth rate of the Chinese market is significantly higher than the global average. In 2023, its market size was approximately RMB 1.4 billion, with a compound annual growth rate of over 15%, which is mainly driven by the rising prevalence of endometriosis and the increasing popularization rate of clinical medication. In terms of the competitive landscape, the domestic preparation market is currently co-occupied by original research drugs and generic drugs, and more than 10 generic drug enterprises have been approved. After the implementation of centralized procurement, the price of preparations has dropped significantly, further driving the continuous expansion of upstream demand for API.

The original research enterprise of dienogest is Bayer HealthCare Co., Ltd., and the original research product is sold under the trade name "Visanne". Its core compound patent expired in Europe in 2022, and the compound patent in China expired in 2021. The main dosage form of the original research product is tablet, with a specification of 2mg per tablet. It has been included in the *Catalogue of Reference Preparations of Chemical Drugs* of China, and is also listed as a reference preparation by the FDA. With respect to domestic API registration, nearly 30 enterprises have submitted the API registration numbers of dienogest as of now, among which more than 20 have passed the A-status publicity. There are 13 approved dienogest preparation varieties in China, covering products of the original research enterprise and multiple generic drug enterprises. (Data as of October 2025, please refer to the official website of CDE for the latest information)

CATO provides a full set of impurity reference standards for dienogest API. The products strictly meet the compliance requirements of multiple regulations such as the Chinese Pharmacopoeia and FDA. Most of the products are in stock. For in-stock orders, delivery can be made on the same day if the order is placed before 16:00, which can fully meet the full-process demands of API manufacturers and R&D institutions for impurity research, quality control, etc.