Thyroid UK


Hi everyone I have diagnosed Hashi's and i'm on 75mg Levothyroxine. Recently I have been having really heavy periods that last nearly 3 weeks, Gp says its thyroid related. Is there any help out there or anything I can do to lesson the days im bleeding or am I stuck with this? I have a endo appointment next month only seen her once and she didn't seem very clued up on the thyroid. Just feeling so desperate been ill for 3 years now with very little help or support from the NHS. I'm 41 years old and obviously female xx

7 Replies

Arjs, can you post your recent thyroid blood results with the lab ref ranges as it will help members to advise. When you are optimally medicated periods and cycle often return to normal.

Ask your GP to check your ferritin and iron as anaemia can be caused by heavy periods and can also cause heavy periods. Ask for vitamin D, B12 and folate to be tested too, they are often low in hypothyroid people.


Im due another blood test tomorrow morning. My test 8 weeks ago was 3.9 (tsh) Not had anything else tested apart from B12 a year ago which was 280. x


Arjs, TSH 3.9 is high. Ask your GP to increase to 100mcg. People on Levothyroxine are usually comfortable with TSH just above or below 1.0 and FT4 half way to three quarters of the way through range. Read the comments of Dr.A.Toft, ex-president of the BTA, on dosing and thyroid levels and show it to your GP.

B12 280 is very low. Neurological symptoms can be experienced when it is under 500. Ask your GP to test it again, if it is below range you will need loading injections to correct deficiency.

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My old GP said this was normal!! To have periods that last 3 weeks that is. As you can imagine I slapped him and told him it was his imagination!!. Take more thyroxine, try it, what have you got to lose? You can always drop it if you feel hyPER.


Very similar to what happened to me but I've suffered for at least 15 years before being put on combined levothyroxine (100)and liothyronine (20). Now periods each 26 days for 4 days and I can leave the house.

With clutter's help I've sorted my vitamins and also take primrose oil everyday. B6 from my third week from my cycle on. Hope you sort this soon. Such a nuisance. All the best


Would just like to add have your iron tested, heavy periods can cause anaemia, and be because of anaemia. You could well do with some prescribed iron. Iron makes your thyroid meds work better anyway.

When I was perimenopausal I had terribly long heavy periods, my then GP prescribed what was for me a wonder drug, it was something with acid included in the name. It made life more tolerable, it was so bad before I went to bed I had 3 big maternity pads on.


First thing I was struck by was the fact your GP actually acknowledged heavy periods are due to your thyroid. Goodness work with that GP. My GP has refused this as a potential cause. I too had periods of two/ three weeks a week off and start again. Exhausting isn't it.

In the three weeks I took NDT up to my op last week it was all settling down again. Day after op and lo and behold all upskittled again.

I think if you were optimally treated this would probably settle but definitely take iron and vit C to compensate.


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