Levothyroxine is a medication used to treat an underactive thyroid, a condition known as hypothyroidism. It works by replacing the hormone that your thyroid gland is unable to produce in sufficient quantities. This helps restore the body's energy and metabolism to normal levels.

### Key Points:
- **Purpose**: Primarily used to treat hypothyroidism, but also used in the treatment of certain types of thyroid cancer and to manage goiter (enlarged thyroid gland).
- **Dosage**: Typically taken once daily, usually in the morning on an empty stomach, at least 30 to 60 minutes before breakfast. The exact dosage depends on the individual's age, weight, and severity of the condition.
- **Side Effects**: Common side effects can include headaches, insomnia, nervousness, and weight loss. More serious side effects should be reported to a healthcare provider immediately.
- **Monitoring**: Regular blood tests are necessary to monitor thyroid hormone levels and adjust the dosage as needed.

### Important Considerations:
- Consistency is key. Taking it at the same time every day ensures stable hormone levels.
- Certain foods and medications can interfere with levothyroxine absorption, so it's important to inform your healthcare provider about all medications and supplements you're taking.
- Sudden changes in symptoms or new symptoms should be discussed with a healthcare professional.

Always consult with a healthcare provider for personalized advice and before making any changes to your medication regimen.