Late period after starting Levothyroxine

[Cloud77]

Has anyone had a delayed period after starting Levothyroxine?

If so when do they normalise and return and is this a common side effect?

Thanks!

[SlowDragon Administrator]

Lily905

That is highly unhelpful comment to someone just starting on levothyroxine

Vast majority of people manage well on levothyroxine once on correct dose

[SlowDragon Administrator]

Yes changes in menstrual cycle are common, especially initially

your previous post shows you are ready for next increase in levothyroxine

healthunlocked.com/thyroidu...

Have you got increase to 75mcg yet?

[RedApple Administrator]

Lily905 'I had a very bad reaction to Thyroxin - it poisoned me & made me really ill'

Some people do not do well on levothyroxine, and need a different form/type of replacement hormone to be well. That does not mean that levothyroxine is poisonous. Levothyroxine is a replacement hormone. It replaces the T4 hormone normally produced by the thyroid gland itself. Levothyroxine (LT4) is most commonly prescribed in tablet form but is also available in liquid form, as well as in desiccated thyroid tablets.

[Cloud77 in reply to RedApple]

Thanks! I hope it’s not the menopause… May I ask how old you were when you took it? I did mention to the GP but told to me to keep an eye on it. From what I have been reading it can interfere with cycles but helpful to get some advice. Thanks!

[RedApple Administrator in reply to Cloud77]

At the moment, your body is experiencing an imbalance of all hormones, both thyroid hormones and sex hormones, which will inevitably upset your normal cycle. It takes time to establish the appropriate dose of replacement thyroid hormone for you, and until then, things such as periods and libido are likely to go haywire. Before worrying about menopause, it's best to wait it out and see if things correct themselves once you've been on the right dose of levothyroxine for some time.

[HealthStarDust in reply to RedApple]

This is sound advice Cloud77 from RedApple . Since I’ve had a disturbance in my latest period (prolonged, not delayed or absent) that’s confirmation enough that my sex hormones are being impacted right now and I suspect will right itself once dose is optimised. For this reason, I have decided there is nothing to be gained from testing sex hormones at the minute (I’m pretty sure I’ve stopped ovulating).

It’s hard not worry, of course. I do too, especially since I wish to have a baby as soon as I am well enough.

Hang in there 🫶🏽

[Cloud77]

Thank you! No not yet…. GP wanted to keep it as it is for another 6 weeks. It’s come down quite quickly. It looks like it is in the correct range as I think about 4.25 now… will see if it reduces any further at the next one. He said he didn’t want to over medicate…

[HealthStarDust in reply to Cloud77]

Oh Gosh! One my GPs decided that I had to stay on a particular dose for 3 months. This made no sense to me on starter doses, nor with the fact I felt (and still do feel) so rubbish.

If you can, listen to your body carefully, and organise blood tests and increases around that. And, try another GP if you can if your percriber isn’t being agreeable.

P.S. once on levothyroxine, TSH would be between the lower end of range and 2 maximum. My GP of course had no idea, but thankfully the lab mentions this in my blood tests results.

[SlowDragon Administrator in reply to Cloud77]

Suggest you see a different GP after next test results

Levothyroxine doesn’t top up failing thyroid, it replaces it

ALWAYS book early morning test, ideally before 9am, only water to drink between waking and test and last dose levothyroxine 24 hours before test

Essential to include Ft4 and Ft3, plus test thyroid antibodies, vitamin D, folate, ferritin and B12 if not already been tested at diagnosis

TSH should be under 2 as an absolute maximum when on levothyroxine

gponline.com/endocrinology-...

Graph showing median TSH in healthy population is 1-1.5

web.archive.org/web/2004060...

Comprehensive list of references for needing LOW TSH on levothyroxine

healthunlocked.com/thyroidu....

onlinelibrary.wiley.com/doi...

If symptoms of hypothyroidism persist despite normalisation of TSH, the dose of levothyroxine can be titrated further to place the TSH in the lower part of the reference range or even slightly below (i.e., TSH: 0.1–2.0 mU/L), but avoiding TSH < 0.1 mU/L. Use of alternate day dosing of different levothyroxine strengths may be needed to achieve this (e.g., 100 mcg for 4 days; 125 mcg for 3 days weekly).

pathlabs.rlbuht.nhs.uk/tft_...

Guiding Treatment with Thyroxine:

In the majority of patients 50-100 μg thyroxine can be used as the starting dose. Alterations in dose are achieved by using 25-50 μg increments and adequacy of the new dose can be confirmed by repeat measurement of TSH after 2-3 months.

The majority of patients will be clinically euthyroid with a ‘normal’ TSH and having thyroxine replacement in the range 75-150 μg/day (1.6ug/Kg on average).

The recommended approach is to titrate thyroxine therapy against the TSH concentration whilst assessing clinical well-being. The target is a serum TSH within the reference range.

……The primary target of thyroxine replacement therapy is to make the patient feel well and to achieve a serum TSH that is within the reference range. The corresponding FT4 will be within or slightly above its reference range.

The minimum period to achieve stable concentrations after a change in dose of thyroxine is two months and thyroid function tests should not normally be requested before this period has elapsed.

[Littleboots12]

Hiya, yep I had the same, it’ll sort itself out. I figured my body had clearly (looking back, once fog had cleared) been out of balance for a good while. 10mths on from starting meds, it is stabilising. Other factors can affect cycles too, we’re not precision engineered clockwork so a few days either way happens. 🙂 Report back to your Dr. when you have a review but bear with it. Take care and look after yourself.

[HealthStarDust in reply to Littleboots12]

Thank you. This is reassuring for me too. I miss my consistent libido and ovulation as I am pretty sure I am not ovulating right now.

[Lily905]

Sorry Slow Dragon, RedApple & the Forum. That's why I wrote "Other people on here who have been taking T4 long term will be able to give you better advice. Best Wishes" because I know not everybody is ill when they start T4. I'll remove my comment & I will not answer anything to do with T4 again. I'm sorry you all thought my comment was highly unhelpful

[RedApple Administrator in reply to Lily905]

Lily905, of course it's absolutely fine to tell how you personally had a bad experience on levothyroxine. It's wrong though, to scare people by likening it to 'poison'. That is a very scary and worrying thing for someone just starting on replacement hormone to read.

[Catseyes235]

It’s quite normal for all your bodily functions to slow down, even your thinking! As your symptoms improve and you get to optimal levels of treatment things should return to normal. Maybe get a print out of best treatment as your GP should be testing you every 6 weeks. …they need educating! Best wishes!

[Dinkki]

Please also ask your doctor to check if you are converting T4 to T3. If you are not, taking t4 is not helpful