Protirelin

There have long been unmet precision diagnosis and treatment needs in clinical scenarios such as central hypothyroidism and differential diagnosis of thyroid diseases. Protirelin, as a synthetic thyrotropin-releasing hormone analog, is a diagnostic drug for regulating the function of the hypothalamic-pituitary-thyroid axis. Its mechanism of action is to specifically stimulate the anterior pituitary to synthesize and release thyroid-stimulating hormone. By monitoring the changes in serum thyroid-stimulating hormone levels after administration, it can assist in determining the lesion site of abnormal hypothalamic-pituitary-thyroid axis function, and can also be used to evaluate the reserve function of pituitary thyroid-stimulating hormone. It is suitable for patients with suspected thyroid axis dysfunction and special populations who need endocrine function assessment.

The overall market size of protirelin is relatively small, mainly concentrated in the field of specialized diagnostic drugs. The annual sales of the global market are approximately USD 80 million to 120 million, with a growth rate maintained in the range of 3% to 5%. The growth momentum mainly comes from the increase in the penetration rate of endocrine disease screening. The domestic market is currently dominated by imported original research products, and no generic drugs have been launched yet. Due to the highly specialized attribute of clinical application scenarios, the overall competitive landscape is relatively loose. If generic drugs pass the consistency evaluation in the future, they are expected to further expand the application scenarios in primary medical institutions with their price advantages. (The data has no verifiable source and is for reference only.)

The original research enterprise of protirelin is Japan's Mitsubishi Tanabe Pharma, and the original research trade name is Thyrel® TRH. Its core compound patent expired in the 1990s, and there is no compound patent restriction in major markets at present. The main dosage form approved for the original research product is injection, with a specification of 500μg per vial. This original research product is not included in China's *Catalogue of Chemical Reference Preparations*, but has been included in the FDA Reference Preparation Catalogue. Up to now, there is no protirelin API with A-status registration number in China, and no protirelin preparation produced by domestic enterprises has been approved for marketing. Only the original imported preparation is approved for clinical supply in China. (The data is as of June 2025, please refer to the official website of CDE for the latest information.)

CATO can provide a full set of impurity reference standards for protirelin API, covering the research needs of the whole path including synthesis process impurities and degradation impurities. Most products are available from stock, and orders placed before 16:00 can be shipped on the same day. All products meet the compliance requirements of multiple regulatory systems such as the Chinese Pharmacopoeia and FDA, and can fully meet the full-process R&D needs of pharmaceutical enterprises in process research, quality control, registration and declaration, etc.