Progesterone is used as contraceptive as

Options

A. It stimulates the secretion of GnRH
B. It inhibits the secretion of GnRH
C. It promote the synthesis of prolactin
D. it inhibits the development of blastocyst

Answer

To solve the question "Progesterone is used as a contraceptive as," we need to analyze the options provided and determine which one accurately describes the role of progesterone in contraception.

### Step-by-Step Solution:

1. **Understanding Progesterone's Role**:
- Progesterone is a hormone that plays a critical role in the menstrual cycle and in maintaining pregnancy. In the context of contraception, it is important to understand how it affects the reproductive hormones.

2. **Analyzing the Options**:
- **Option 1**: "It stimulates the secretion of GnRH."
- This option is incorrect. Progesterone does not stimulate the secretion of Gonadotropin-Releasing Hormone (GnRH); rather, it has an inhibitory effect.

- **Option 2**: "It inhibits the secretion of GnRH."
- This option is correct. Progesterone inhibits the secretion of GnRH, which in turn reduces the secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), preventing ovulation and thus acting as a contraceptive.

- **Option 3**: "Promotes the synthesis of Prolactin."
- This option is incorrect. High levels of progesterone do not promote prolactin synthesis; in fact, it can inhibit it. Prolactin is more associated with lactation and is influenced by other factors.

- **Option 4**: "It inhibits the development of the blastocyst."
- This option is also incorrect. While progesterone is important for maintaining the uterine lining for implantation, it does not inhibit the development of the blastocyst.

3. **Conclusion**:
- Based on the analysis, the correct answer is **Option 2: It inhibits the secretion of GnRH**. This mechanism is crucial for its contraceptive effect.

### Final Answer:
**Progesterone is used as a contraceptive as it inhibits the secretion of GnRH.**