**Question:** All of the following drugs can cause gynaecomastia except:-

A. Testosterone
B. Anabolic steroids
C. Progesterone
D. Oral contraceptives

**Core Concept:** Gynaecomastia is the pathological enlargement of breast tissue in males, typically caused by hormonal imbalances or exposure to certain drugs, chemicals, or medical conditions.

**Why the Correct Answer is Right:**
Drugs like Testosterone and Anabolic steroids increase the production of estrogen and androgens, leading to an imbalance between estrogen and androgen levels, which results in gynaecomastia. Progesterone, on the other hand, is a hormone produced by the corpus luteum and placenta that has anti-androgenic effects, decreasing the production of testosterone and other androgens, thus reducing the risk of gynaecomastia. Oral contraceptives contain a combination of estrogen and progestin, which also helps in preventing gynaecomastia by suppressing the production of androgens in the testes.

**Why Each Wrong Option is Incorrect:**
Option C (Progesterone) is incorrect because it has anti-androgenic effects and reduces the production of testosterone and other androgens. Testosterone and Anabolic steroids (Option A and B) increase the production of estrogen and androgens, leading to an imbalance between estrogen and androgen levels, which results in gynaecomastia. Oral contraceptives (Option D) contain a combination of estrogen and progestin, which suppresses the production of androgens in the testes.

**Clinical Pearl:** A thorough understanding of hormonal mechanisms and drug actions is crucial in preventing and managing gynaecomastia in patients, particularly when prescribing anabolic steroids or testosterone therapy, which are often used in the treatment of hypogonadism, Klinefelter's syndrome, or conditions associated with decreased testosterone production.

**Correct Answer:** D. Oral contraceptives

**Why the Correct Answer is Right:**
Oral contraceptives contain a combination of estrogen and progestin, which suppresses the production of androgens in the testes. This helps prevent gynaecomastia by mitigating the excess androgen production.

**Why Each Wrong Option is Incorrect:**
A. Testosterone and Anabolic steroids: Increased androgen production leads to gynaecomastia. By contrast, these drugs increase the production of estrogen and androgens, causing an imbalance that results in gynaecomastia.

B. Progesterone: Progesterone is a hormone that plays a crucial role in the luteal phase of the menstrual cycle and is not directly linked to the development of gynaecomastia.

C. Oral contraceptives: Oral contraceptives contain a combination of estrogen and progestin, which suppresses the production of androgens in the testes, thereby preventing gynaecomast