What will happen if you stop taking thyroid meds?

Your low thyroid symptoms will start coming back, fatigue, dry skin, low sex drive, others.  Your constant menstruation can be handled with a low dose of hormones from your gynecologist.  The Synthroid really regulates the thyroid gland, not the hormonal output.

I don't believe that your thyroid medication has anything to do with your menustration.  I have Grave's disease (hyperthyroidism) but was treated with RAI and now have hypothyroidism.  One of the common symptoms of hypothyroidism is irregular periods - - not periods that continue.  Also, please please be aware that when you stop your thyroid medication you can get hyperthyroidism which can cause high blood pressure and heart problems.  It IS NOT safe to come off of your thyroid medication.  Please get back on it ASAP.  Synthroid is a natural hormone your body now needs.

I don't have a problem with my thyroid. When I went through the menopause I would get periods every 3 weeks, last for 5 days and were so heavy that there were many times I wondered if I should go to the ER.

You need to go back to your doctor. Maybe a lower dose of thyroid would be better. And you should have a blood to determine if you are anemic. If you are you will need to take iron supplements. Anemia makes the bleeding worse.

After you went on the medication, did your doctor give you a blood test to see if you were on the proper dose. Your dose may have been too high.

See an endocrinologist and get a 2nd opinion.

I had my thyroid remove, and take synthroid. Frequently my dose needs to be adjusted.

You want to see your blood test to determine where you stand and where you were when the doctor diagnosed you. If anything thyroid medicine usually fixes irregulated periods. Make sure you get checked out by your gyno as well as get test results as thyroid may not be the reason for heavy bleeding. There is a lot you can do manage thyroid conditions, menapausal conditions to live a healthy life. Good luck to you!