Thyroid UK
87,389 members102,098 posts

Thyroid S first day - no side effects

Hi, I'd really appreciate some advice if possible.

I switched from 125 levo to Thyroid S today. I took 1 grain this morning at 7am and another at 12 midday.

So far I have no side effects at all. I was expecting palpations as I've read that you need to start slowly and work your way up (which obviously I totally disregarded lol)

I intend to stay on this dose for at least 4 weeks. TSH is 5.7 at the moment (0.4 - 4.0).

I don't know if I should feel lucky or concerned about the lack of side effects.

I'd love to hear your experiences of switching from levo to Ndt please.

Thanks so much x

6 Replies


Welcome to our forum.

We sometimes have to acclimatise our bodies to the T3 that the NDT contains as our bodies become intolerant to this hormone we may have been missing for a long time.

Two grains of NDT will take you slightly over your dose of T4 alone and bearing in mind you haven't been medicating T3, you may find you experience inner heat, a headache or palpations.

If you post any test results complete with ranges (numbers in brackets) members will comment.

It is advisable to retest bloods after six weeks to establish where you are.


Thank you radd.

I have had a headache today but that's not uncommon for me anyway.

I was mainly worrying that I would end up needing a huge dose down the line if 2 grains at the beginning wasn't really effecting me.

Sorry about not posting ranges, I didn't realise.

The ranges for TSH here is between 0.4 and 4.0 so I should have wrote that my TSH is 5.7 (0.4 to 4.0) is that right?

Thanks again, I'll be getting retested in 6 weeks.




TSH is high when medicating 125mcg Levo.

Hopefully the T3 in the NDT will help you to feel better but you will need to leave it several weeks for full benefit to be felt.

Have you had thyroid antibodies (TPOAb & TGAb) tested ? ?

Also Vit B12, Vit D, folate and ferritin tested ? . These are commonly low in people with low thyroid hormone and may impair further good thyroid function.

Post any further test results complete with ranges (numbers in brackets) for members to comment.


Hi PF, your body needs some time to acclimitise to T3 which can take four to six weeks. No effects on day one will mean nothing really. Try 1/2 grain for a couple of weeks and then raise slowly by a quarter to half a grain every two weeks. Some people can switch straight over without the slow start, but everyone is different. I have posted this link as it gives a good example of how thyroid hormones need to slowly absorb into our cells.


Hi I started on NDT in mid June. I am currently on 2.5 per day. It seems fine I have noticed that it takes weeks for the body to get used to T3.again. I was on 3 per day but lowered it and i'm still tweeking the dose myself. I only take notice of how I feel and don't rely on blood tests to much. Good luck.

1 like

Hi. Agree with Bunnyjean. With NDT you need to dose by how you feel not TSH. Always try and take more rather than less, but after a few weeks you will begin to recognize the symptoms of being high or low for you. It is different for different people. For me - Low is feeling cold and even running a low temp 35.1C , sluggish heart beat (45). To much is feeling hot, temp 36.7C, tingly hands and feet, heart palpitations in bed at night.

Just keep adding a little more (.25 Grains of NDT) extra every few days until you are Hyper (high dose) then back it down a little. You need varying amounts depending on your activities , stay home and watch movies and you might need 1.5 -2 grains, go ice skating for a few hours and that day you need 3 Grains to make up for the cold and the exercise.

The T4 in NDT and Levo take up to 6 weeks to plato in you body tissue, so what works now wont work in 6 weeks - so there is little point in sticking on some regiment blood test driven dose set by a doctor, you need to work your own body out. Funny enough if you always try and take the most you can take each day rather than the least - your blood tests will come back fine.

Best of luck


You may also like...