Levothyroxine
Written By Dr. Lipika Khurana
Reviewed By Dr. Rajeev SharmaLast updated 25 Nov 2025 | 09:34 AM (UTC)
Levothyroxine Uses
Levothyroxine is used in the treatment of hypothyroidism.
How Levothyroxine works
Levothyroxine is a synthetic version of a hormone produced by the thyroid gland. It works by replacing the thyroid hormones that your thyroid gland cannot produce. This leads to improved energy production, oxygen consumption, protein synthesis, and overall regulation of metabolism, helping restore normal thyroid function and physiological balance.
Common side effects of Levothyroxine
Headache, Increased appetite, Irregular menstrual cycle, Insomnia (difficulty in sleeping), Arrhythmia (irregular heartbeats), Heart attack, Breathlessness, Muscle spasm, Irritability, Tremors, Muscle weakness, Weight loss, Diarrhea, Heat intolerance, Skin rash
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Expert advice for Levothyroxine
- Always take Levothyroxine at least 30 minutes before breakfast with a full glass of water to ensure proper absorption.
- Take your dose at the same time every day to maintain stable thyroid hormone levels in your body.
- Avoid certain foods and supplements such as calcium, iron supplements, soy products, and antacids as they can interfere with absorption.
- Keep track of how you feel, and report symptoms like fatigue, weight changes, or palpitations to your doctor for possible dose adjustments.
- Do not skip or adjust the dose on your own, as missing doses or changing the dosage without medical advice can lead to imbalanced thyroid levels and unwanted side effects.
Frequently asked questions for Levothyroxine
Take Levothyroxine on an empty stomach with a full glass of water. Avoid taking it with calcium, iron, or antacids, as they can interfere with absorption.
Avoid Levothyroxine if you have untreated adrenal or thyroid disorders, recent heart issues, or an allergy to any of its ingredients. Pregnant women should not use it alongside antithyroid medications.
If you miss a dose, take it as soon as you remember. If it is close to your next scheduled dose, skip the missed dose and continue with your regular schedule. Do not take two doses at once.