<s>[INST] Hello! My name is Maxine, I`m 26 and I have some questions concerning thyroid cancer and birth control. I was diagnosed with papillary thyroid cancer 10 months ago and had a full thyroidectomy . So far I have received 145 mci of RAI, 100 of which were given for treating lymph node metastasis . There are some undifferenciated areas on my CT scans (neck and mediastinum ) so I`m still in the status of a cancer patient. My therapy is 150 micrograms of Euthyrox. I`m considering starting another birth control measure in addition to using condoms. Is it problematic to use hormonal birth control while on Euthyrox, especially if the cancer is still present in the form of metastasis? I would appreciate your help, thank you. [/INST] Dear,you are being given Euthyrox 150mcg daily so that you are not thyroid defficient and to creat a feeling in the body as if thyroid was not removed. so you can use hormonal contraceptives like a normal person would have used it with no problems. Had you not been on replacement therapy,  hypothyriodism itself acts as a birth control measure. regarding your thyroid malignancy you may have to undergo RAI uptake study again as per the advice of your physician to rule out the complete ablation of your disease.Truly,Dr. J. Ticku </s>