Can my birth control pills change the dose of thyroid medication I need?
Ask the doctor
Q. Is there any interaction from taking levothyroxine and birth control pills together?
A. Most birth control pills contain a combination of two female hormones, estrogen and a progestin. Assuming that your pill contains estrogen, it will interact with the levothyroxine (a synthetic type of thyroid hormone).
The explanation for this interaction gets a little complicated. But the bottom line is you don't need to stop the birth control pills. You may need to take a slightly higher dose of levothyroxine while you are on the estrogen-containing pill.
Your doctor can order a blood test called TSH (thyroid-stimulating hormone) to see if your thyroid dose needs to be a little higher.
The interaction between estrogen and levothyroxine also applies to women who take estrogen for relief of menopausal symptoms.
Image: © Cris Cantón/Getty Images
About the Author
Howard E. LeWine, MD, Chief Medical Editor, Harvard Health Publishing; Editorial Advisory Board Member, Harvard Health Publishing
Disclaimer:
As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review or update on all articles.
No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.
