**Question:** Gestrinone has following actions except

A. Oestrogenic actions
B. Progestogenic actions
C. Androgenic actions
D. Gonadotropin-releasing hormone (GnRH) antagonism

**Core Concept:** Gestrinone is a synthetic steroid hormone primarily used as an oral contraceptive and an anti-fertility agent. It is a synthetic derivative of the natural hormone, diethylstilbestrol (DES), which has a similar structure and biological activity. Gestrinone exhibits diverse actions due to its unique chemical structure, including oestrogenic, progestogenic, and anti-androgenic effects.

**Why the Correct Answer is Right:** Gestrinone possesses anti-androgenic and anti-Gonadotropin-releasing hormone (GnRH) actions that contribute to its contraceptive and anti-fertility effects. This makes option D incorrect because Gestrinone does not directly target androgenic pathways.

**Why Each Wrong Option is Incorrect:**

A. Oestrogenic actions: Gestrinone does have oestrogenic effects, although its overall hormonal balance is skewed towards progestogenic and anti-androgenic effects. This makes option A incorrect as oestrogenic activity is part of Gestrinone's pharmacology.

B. Progestogenic actions: Gestrinone is a progestogenic agent, as it mimics the actions of progesterone by binding to the progesterone receptor and inhibiting luteinizing hormone (LH) and follicle-stimulating hormone (FSH) secretion, thereby inhibiting ovulation and menstruation. This makes option B correct as progestogenic actions are a part of Gestrinone's pharmacology.

C. Androgenic actions: Gestrinone possesses anti-androgenic properties, as it interferes with androgen biosynthesis and action by inhibiting the enzyme 5α-reductase and reducing the conversion of testosterone to dihydrotestosterone (DHT). This makes option C incorrect as androgenic actions are counteracted by Gestrinone's pharmacology.

**Clinical Pearl:** Understanding the pharmacology of Gestrinone is essential for its clinical use in contraception and anti-fertility treatments. The balanced hormonal effects of Gestrinone, including its anti-androgenic and progestogenic actions, contribute to its effectiveness in preventing pregnancy and regulating menstrual cycles. The correct answer is option B (Progestogenic actions) because Gestrinone's progestogenic effects are a key component of its pharmacology, contributing to its contraceptive and anti-fertility properties.