About Thyroxine (levothyroxine)
Medically reviewed by Dr Khizer Hussain Junaidy, MD Pharmacology, Diabetologist & Bariatric Physician, on 23 Oct 2026.
What it is for
Replaces thyroid hormone when the thyroid is underactive (hypothyroidism).
How to take it
Take it on an empty stomach, first thing in the morning with water, 30 to 60 minutes before tea, coffee, breakfast or other tablets. Keep 4 hours between thyroxine and calcium or iron tablets.
Common side effects
- Usually none at the right dose.
- Too high a dose: palpitations, sweating, poor sleep, weight loss.
Call your doctor if
- Chest pain or fast heartbeat.
- Pregnancy. The dose usually needs to go up early.
Take care
Do not switch brands often; tell the doctor if you do.
From our clinic: TSH is checked 6 to 8 weeks after any dose change.