Is there any interaction from taking levothyroxine and birth control pills together?
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 interation gets a little complicated. But the bottom line is you dont 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.
