Thyroid UK
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When to start my T3?

Hi all, endocrinologist has finally given me a trial of Liothyronine(T3) 10mcg and lowered my Levo dose to 100mcg (previously 125mcg). This is a moment that I've been waiting for but now I am apprehensive to start taking them just in case I've not got all my ducks in a row to really get the best benefits and it turns out not to be the miracle pill I am secretly hoping it will be! Haha!

I know I'm low in range on Ferritin, folate, Vit d and B12 so have bought all supplements ready to start along with Magnesium, Selenium etc.

Question is do I start the vitamins now and give them a few weeks to kick in before I change over to T3 dose too? Or do I just start my T3 now? What time of day should I take it? I usually take Levo at night but not sure if that's the right thing to do for t3?

Your help would be appreciated! 😊 thank you! X

10 Replies

It's perfectly ok to take your T3 at night, with your levo.

For the vitamins and minerals, do not start them all at once. Start with one, and leave about two weeks before starting the next one.

My personal opinion is that you should start on the T3 first, but just 5 mcg, not the whole 10 at once. Add in the next 5 after about a week. Stay on that for a couple of weeks, and then start adding in the vitamins and minerals. Slow and steady wins the race! :)


T3 of 10mcg per day divided into 4 equal doses taken at roughly 6 hour intervals through 24 hours plus 50 mcg of T4 was the right protocol for me. Your total dose will be individual to you but some people find they need to take the T3 in even smaller doses so don't worry if you find even 5 mcg at one time is too much. With difficultly I've managed so far to be prescribed 5 mcg tablets of T3 from NHS doctor which I can divide into 2.


Hi Tarajp, great that your endo has offered T3. I'm not as experienced as many others here but just thought I would mention my current experience. I've been on 75mcg Levo for many years, tried to increase to 100mcg but couldn't tolerate it, had adverse symptoms creep in after a couple of weeks.

But recently (long story) saw an Endo in London who offered me two different lines of treatment which I could do either or both. For various reasons I chose the route of NDT which he prescribed and sent in the post. Like you I was extremely apprehensive but decided to try and have faith in the Endo (as my husband said, you've paid all that money, try and trust him) but knowing that NDT contains T3 which isn't in Levo, I felt sure it would have some sort of effect.

The first 3 days were completely uneventful and I breathed a sigh of relief (switched from Levo one day to NDT the next) but by day 4, I felt quite poorly in many ways. When I looked at a site where you can buy the NDT, there was a small sentence describing a list of side effects you may get initially. I seemed to have quite a few of them and the site said this indicates the dose is too high for you to tolerate the T3 initially.

So the next day I halved the dose, managed to crack the tablets in half and got to the end of the week feeling much better, well back to how I was before starting NDT but I didn't expect miracles. After asking lots of questions in this forum and another, several people mentioned that of course everyone is different, some will tolerate more than others, but one lady told me how she raised her dose in very small increments and it took longer, but it was much better for her. So thats what I'm doing.

I don't have nearly as much knowledge as Greygoose (I read all your replies GG) but I would agree on going lower on the T3 to begin with.

I know just how you feel about hanging your hopes on something hoping you're going to feel amazing quite soon and then worrying about it not working. I think perhaps most people switching or altering meds feel the same. So I would be cautious on the T3 dosing and if you do get side effects, try lowering the dose a little bit. I'm sure someone else will help with regard to the ducks in a row before starting T3.

If you do have to split tablets at some point, I posted about this and got all sorts of recommendations of pill cutters costing £10 up to £20. Yesterday I went into a large Boots store and asked for a pill cutter. They had one only. It was £2.99. Thought it was worth trying and it works perfectly! :-)

Good luck with your new journey. x


It certainly made a difference to my life. I take mine in the morning with my T4 as that is what I was told to do. No idea what my vitamins are like apart from D as that's the only one they've ever tested. It's a bit low at the moment and I'm trying to get it up a bit but can't say it's had any effect on thyroid..


It seems that if you split your dose of T3 this is best. Never having taken T3 this is all I can say.


No, I don't agree splitting dose is better. Some may do so but it is required to saturate all the receptor cells then its work begins and lasts between one to three days. Also food interferes with the uptake of thyroid hormones, so your stomach has to be empty:-


I want to emphasize, however, that when our protocol is used properly, there is no overstimulation to be avoided by using timed-release T3. The protocol has safeguards against adverse effects.

And finally, why do I specify that the typical patient use one full dose of non-timed-release Cytomel for life? Because extensive testing has shown that this is safe, effective, and most economical—when used within the context of our entire protocol.


Go for it! Remember on an empty stomach or a few hours after food or drink, with water, then wait half an hour before food or drink. You may feel flutterings in your neck for a week but nothing earth shattering. If you suffer constipation they work like a charm for that!


Because hypo causes everything to slow down, so does digestion and this is an excerpt:

Dr. Lowe: As a rule, our patients take thyroid hormone only once per day. An advantage of this one-per-day schedule is that it’s easier to find a window for good intestinal absorption—when the stomach or small intestine doesn’t contain food.

Most of our patients wait at least one hour after taking thyroid hormone before they eat. Or they wait at least two hours after eating before they take thyroid hormone. The two hour wait is a rough estimate of the time it takes for food to pass through the stomach and small intestine. It’s worth noting, however, that several factors can increase the time a patient should wait before taking thyroid hormone.

One factor is being female. Researchers report that on average, the woman’s stomach empties more slowly than the man’s. In a 1998 study, for example, researchers tested how long it took for half of a solid meal to empty from the stomachs of healthy women and men. The average time for women was 86 minutes and for men was 52 minutes.[1] This result is consistent with those of other studies; it suggests that women may benefit by waiting a while longer than men after eating to take thyroid hormone.

Another factor is the slower movement of food and stool through the gastro-intestinal (GI) tract of many patients who have hypothyroidism or thyroid hormone resistance. Doctors often diagnose the sluggish GI function as "constipation-type irritable bowel syndrome."[2,pp.681-687] Until the patient finds a thyroid hormone dose that relieves her constipation, it may be prudent for her to allow more than two hours—maybe three—for food to clear from her stomach and small intestine before taking the hormone.


Thank you shaws, very comprehensive info.


I've been taking 20mg of T3 for 18 months along with 75mg and 50mg T4 alternate days. I was told by my specialist that T3 does not last as long in your system so I take 10mg in the morning and 10mg in the afternoon about 2pm. I found if I forgot and took it later say at tea time it kept me awake. So I'd definitely split your dose up. I take selenium, magnesium, zinc,B12, liquid iron as I have hashimotos autoimmune disease too and liquid iron is better absorbed and doesn't aggravate the tummy as much. I also have omega 3, evening primrose oil and vitamin D. These are all vitamins that I have read that with underactive thyroid you may be deficient in. I do feel better when I'm on them. My iron an vit D have been very low before. Also if you are in the range for iron it's not enough. My specialist said we need to be at least in the 60s to feel well so if that's on about 11-20 it's still too low. I've felt worse since mine dropped from 60-20 in 3 months, but I believe it's coming up with the liquid iron now. I buy it from Amazon, it's expensive but I no longer get pains and constipation like I did with iron tablets. Your diet is equally important too. It's not just the medication. Last year my life changed dramatically for the better when I cut out wheat,sugar,dairy and potatoes. Paleo is the type of diet that really helps thyroid patients. We also need plenty of sleep at least 8-10 hours. So the T3 wasn't my miracle cure but the combination of T3,diet and sleep were. Good luck. Xx

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