Medications
Thyroid Medicine Before Surgery
Thyroid medicine is one of the simpler ones to manage before surgery.
Medically reviewed by
Dr. Saurabh Shukla, MBBS, DNB Anesthesiology
· Last updated June 2026
Quick answer
Keep taking your thyroid medicine. Levothyroxine can be taken on the morning of surgery with a small sip of water — and because it stays in your body for a long time, it's also safe to skip a single dose if your team prefers.
Why it matters
Thyroid hormone levels change very slowly, so one missed dose doesn't affect your thyroid control. That makes thyroid medicine low-risk around surgery.
The goal is simply to keep your thyroid stable. Stopping it for days isn't recommended, but there's no urgency about the exact timing of a single dose.
Do not stop without instruction
Don't stop your thyroid medicine in the days before surgery. Keep your usual routine unless told otherwise.
What to ask your doctor
- Should I take my thyroid tablet on the morning of surgery, or skip that one dose?
- Do I need any thyroid blood tests before surgery?
- When do I resume my normal routine afterward?
Red flags — call your team
Red flags — call your team
- Known severe under- or over-active thyroid that isn't controlled
- Racing heart, tremor, or feeling very unwell
References
- American Society of Anesthesiologists (ASA) — perioperative medication management. asahq.org
Frequently asked questions
Do I take levothyroxine before surgery?
Yes, usually. Take it on the morning of surgery with a sip of water, or skip a single dose if your team advises — it's long-acting and one dose makes little difference.