T3 Liothyronin weight gain: Hi all, I’ve been on... - Thyroid UK

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T3 Liothyronin weight gain

Wired123 profile image

Hi all, I’ve been on Lio for 7 months now and put on a stone in that time. My body shape is also very different to how it used to be, others have noticed the difference in shape.

In case it’s relevant I’m male.

Is this common? My previous Endo (who started me on T3) didn’t have a clue and suggested I think about diet and exercise. So I bid him and his lazy backside goodbye.

My diet nor exercise levels have changed so the weight gain is puzzling.

My morning cortisol is higher now since starting T3 (has been very low for years), this has been beneficial as I can now wake up in the mornings without any trouble. However I wonder if the higher cortisol is contributing to weight gain?

Any other ideas will be gratefully received.

I’m seeing my new Endo for follow up with my results next week and want to have enough to challenge her on/suggest further testing.

67 Replies
SlowDragon profile image

Please add most recent results and ranges if you have any

How much levothyroxine are you currently taking, do you always get same brand of levothyroxine at each prescription

How much T3

Do you split T3 into 2 or 3 smaller doses through the day

Always same brand of T3?

What vitamin supplements are you currently taking

When were vitamin D, folate, ferritin and B12 last tested?

As you have Hashimoto’s are you on absolutely strictly gluten free diet

all thyroid blood tests should ideally be done as early as possible in morning and before eating or drinking anything other than water .

Last dose of Levothyroxine 24 hours prior to blood test. (taking delayed dose immediately after blood draw).

This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip)

When on T3, day before test, split dose into three smaller doses roughly equal 8 hour intervals. Taking last dose T3 at roughly 8-12 hours before test (even if normally take as single dose)

Is this how you do your tests?

Private tests are available as NHS currently rarely tests Ft3 or thyroid antibodies or all relevant vitamins

List of private testing options


Medichecks Thyroid plus antibodies and vitamins


Thriva Thyroid plus antibodies and vitamins By DIY fingerpick test


Thriva also offer just vitamin testing

Blue Horizon Thyroid Premium Gold includes antibodies, cortisol and vitamins by DIY fingerprick test


cheapest option for just TSH, FT4 and FT3

£29 (via NHS private service ) and 10% off down to £26.10 if go on thyroid uk for code



Wired123 profile image
Wired123 in reply to SlowDragon

Thanks SlowDragon, I’m more interested in people’s experiences of weight changes on T3.

Latest blood results won’t be available till next week and I will post them once I have them.

My previous private Endo was happy with my T3 and T4 levels and I’ve felt good, just the weight gain is a possible undesirable side effect.

SlowDragon profile image
SlowDragonAdministrator in reply to Wired123

Well if you’re under medicated, it’s likely

Obviously TSH is almost always suppressed on T3

You’re currently on tiny dose T3 so it’s very odd your Ft3 is high

Do you test as advised on here

Was Ft3 low before T3 was added?

Are all vitamins optimal

shaws profile image

What dose of T3 do you take. Do you take it once daily with one full glass of water and wait an hour before eating?

Wired123 profile image
Wired123 in reply to shaws

5mcg on waking with 150mcg T4. Yes wait an hour before eating breakfast.

Second dose of T3 (currently 2.5mcg, was previously 5mcg) at 2.30pm well clear of lunch.

Blood tests show high T3 and T4, suppressed TSH so private Endo was happy.

Do you do a lot of exercise? Are you GF? I wouldn’t have thought the cortisol would cause weight gain. Interested to see your most recent blood results.

shaws profile image
shawsAdministrator in reply to Wired123

I've always taken one daily dose of T3, as recommended by one of TUK's Advisers who was an expert in the use of T3.Going by 'how I feel'.

Levothyroxine, for me, was a complete nightmare - and 'nightmare' is appropriate as I was awakened each and every night with such severe palpitations that the cardiologist was puzzled and was suggesting I have an implant in my chest to record my heart. Just at the same time T3 was added to a reduced T4 and it was a revelation in that severe palps ceased and I didn't need the implant. I then went onto T3 only.

Dr Lowe stated that 'one daily dose' of T3 with a full glass of water saturated all of the T3 receptor cells, and it sent out 'waves' throughout the day. He also stated that one dose could last up to three days.

I trialled and took one daily dose of T3, took none on day 2 or day 3 and the effect of that one dose did last for me .

I have adjusted dose and reduced slightly and now take one daily dose of 20mcg of T3 with one glass of water.

Dr John Lowe - himself took his dose of 140mcg of T3 in the middle of the night when he awoke so that nothing at all interfered with its uptake

He didn't recommend splitting the dose as he stated T3 had to saturate all T3 receptor cells. He himself took 150mcg of T3 but in the middle of the night when he awoke so that nothing interfered with its uptake. He was then capable of doing research etc. He would never prescribe levothyroxine. He also stated that one daily dose (at the appropriate dose for that person) could last up to three days.

I took one daily dose, took none on day 2, and none on day 3 and it did last (I only trialled that once only).

He prescribed NDTs (natural dessicated thyroid hormones that contain all of the hormones a healthy thyroid gland would do. (now withdrawn in the UK). NDTs were the very first replacements from 1892 onwards and it saved lives from then on and still does today.

I often wonder about those medical professionals who withdraw replacement hormones without notice - or even with notice as many people's health had been restored and they were devasted when those who we expect to know more than us, it seems to me, that they know less. That's because they work on 'suppositions' I believe and think they know best, but they can be wrong for some people.

The professionals, who most probably don't have a dysfunctional thyroid gland cannot tell those who have it that they are no longer going to get the tablet that made them feel well again. However, that's what they did re NDT and T3 and there was no gradual changeover but instant causing so much worry and mental health issues when you suspect you're going to be very unwell again.

shaws profile image
shawsAdministrator in reply to Wired123

Your dose of T3 is very low.

I take T3 alone and I used to take a slightly higher dose but going by my symptoms I now take 25mcg once daily. If your T3 is higher, it can be due to you being a good converter of levothyroxine (T4) into liothyronine (T3) and that is what is supposed to do because T4 is an inactive hormone and should convert to T3.

Levothyroxine (T4) is a pro drug converted to liothyronine (T3) in the body [3].

Wirral Guidance on the Prescribing of Liothyronine (T3 ...

mm.wirral.nhs.uk › guidelines › Liothyronine...

Are levothyroxine and liothyronine the same?

Does levothyroxine convert to T3?

T3 is the body's active form of the thyroid hormone thyroxine. Enzymes in organs like the liver, brain, and heart convert thyroxine (T4) into T3 and the thyroid gland produces some as well. For most people with hypothyroidism, the body converts levothyroxine into sufficient T3.10 Oct 2017

6 Thyroid Medication Mistakes You Don't Want to Make - Plus, how

Can you post your most recent bloods? Really hard to advise without this.

Hi Wired123

I am on 75mcg levo and 20mcg lio. 4 months now. I can say I haven’t put on weight but I haven’t lost any either. I have struggled with keeping the weight off for ages and really started to gain weight around October 2020. I put this down to be undermedicated. I discovered I was and probably have always been and believe I still am.

What I will say is that I noticed a change in how I carried the extra weight. I have a real lack of muscle tone. I feel that there maybe something in the theory of mucin storing water. I am hoping that whether it be extra water or fat once properly medicated, I will be able to shift it.

I notice you take quite a low dose of t3 and have been on this for a while. I realise your endo reports that your levels are good but did he actually say what they are? My endo told me my levels were good for 3 years before I educated myself a bit and questioned it. They were very low in the range.

Good luck.

Interesting experience you’ve had.

I’m on a dose that’s enough to get me to the top of the range of T3 so I think that’s enough hormone.

I’ve come down from 2 x 5mcg a day to 1 x 5mcg + 1 x 2.5mcg. I do notice I’m losing muscle strength and stamina as well, so perhaps I need a bit more. Will see what Endo thinks next week but trying to gather experiences on here, so far no one else has experienced weight gain on T3 so it is very very strange!

I took a look at your link to blood tests 2 months ago. How long have you been gaining weight? All that time? I wonder if it is just that you’re not ‘stable’. Your levels have been fluctuating and so perhaps you need a longer length of time on this dose to see if it settles? Either that or maybe you’ll be surprised when you see your latest results as they may show lower levels.

I would be interested to see if one the bright sparks replies to you and what they think.

Sincerely hope that it’s a temporary glitch for you. I know I was hoping to be all trim within a few months! I hope t3 doesn’t put pay to that!! 😱🤣

Lastly, what lio do you take? Have you considered the fillers? I know people tend to have different reactions to different fillers 🤷‍♀️ Clutching at straws??

I’m deliberately not posting results as those results look pretty good. They are available on my previous post 2 months ago:


Latest set of blood results will also be available next week.

I don’t think the bloods are relevant, the question remains whether anyone has experienced weight gain after adding T3 accompanied by a change in body shape.

Clearly something hormonal is at play.

I’ve been hashis since 2008 and on T4 mono till Nov 2020 after which T3 was introduced. Diet and exercise unchanged since adding T3 so I believe T3 is the culprit either directly or indirectly. Cortisol is what I suspect is at play here.

Steni profile image
Steni in reply to Wired123

It’s so frustrating that everyone just keeps asking for blood tests when what you really want to know is has anyone else had the same experience. I’m interested to hear if anyone else’s experience is similar.

Fitly profile image
Fitly in reply to Wired123

I have been on T3 since Sep2020 (raised from 10-15 in December) with 75 levo and have gained one stone in that time. I am female. I should say that t3 has completely transformed my life so I wouldbear the gain but it is frustrating. I exercise regularly and am very active though undoubtedly don’t have the stamina or strength that I had pre Hashis, I am more energised since T3.. I also notice that while T3 picks me up so I can almost resume earlier levels of exercise - if I overdo it I really crash. One thing I have noticed is that I am hungrier - I wonder if the metabolism shift actually might cause that- so although I am a healthy eater I might be eating more- I should keep a food diary. The fat is definitely around my belly area which is not normally where I carry any excess weight. I also get 3 monthly B12 injections and supplement vit D.


This post by Dr Eric Balcavage explains how initially some people feel well increasing T3 but then they hit a plateau as they experience the cell danger response. So your body deactivates T3 at the cellular level.


Dr Balcavage

Now this is very interesting. I did feel amazing after starting T3, it tailed off a bit. However I am still better on it than off it, particularly around brain function and general energy levels.

Steni profile image
Steni in reply to Wired123

Wow that’s so interesting - and really speaks to your question I think

SlowDragon profile image

Looking at previous posts, 7 months ago ferritin was low, at 48.....especially for a male

Have you retested ferritin recently?

Wired123 profile image
Wired123 in reply to SlowDragon

Ferritin is a red herring, have had iron investigations by 2 private Haematologists. Good spot anyway!

Not everyone can have high iron stores (Ferritin) but as long as serum iron and Haemoglobin are good there’s no issues.

SlowDragon profile image
SlowDragonAdministrator in reply to Wired123

When on levothyroxine/T3 we need good ferritin levels

If iron levels are good, then don’t need supplements. Instead Look at increasing iron rich foods in diet

Eating iron rich foods like liver or liver pate once a week plus other red meat, pumpkin seeds and dark chocolate, plus daily orange juice or other vitamin C rich drink can help improve iron absorption

List of iron rich foods


Links about iron and ferritin



Great in-depth article on low ferritin



This is interesting because I have noticed that many patients with Hashimoto’s disease and hypothyroidism, start to feel worse when their ferritin drops below 80 and usually there is hair loss when it drops below 50.



Post discussing just how long it can take to raise low ferritin


shaws profile image

What dose of T3 do you take?

I've taken lio for a few years and haven't gained any weight.

Usually, on the forum, some people who take levo alone gain weight but mostly it is because they aren't on an optimum dose or their metabolism hasn't improved.

The most common 'weight gain' post is from members who're on levothyroxine alone. The following link might be helpful:-


Wired123 profile image
Wired123 in reply to shaws

Thanks, I’ve been on 10mcg for most of the time but recently dropped down to 7.5mcg. The point is the weight gain has started after adding in T3, so it’s strange that it caused weight gain as nothing else has changed.

shaws profile image
shawsAdministrator in reply to Wired123

Could it be due to you not having a sufficient dose of T3? I have read that 25mcg of T3 is approx equal to 100mcg of levothyroxine and I think most members believe that too.

According to the link below it isn't in agreement and states:-

"Equivalency statements in the product monographs for Pfizer Canada’s Cytomel and for ERFA Canada’s “Thyroid” (NDT brand) claim that a 25 mcg dose of Liothyronine sodium (L-T3) is “considered equivalent” to 100 mcg / μg (0.1 mg) of Levothyroxine sodium (L-T4).

These statements communicate a misleading message to doctors and patients because they do not provide dose ranges, but rather precise doses.

They imply that a simple mathematical calculation can estimate dosages of each pharmaceutical in any ratio, either as a combination, or as monotherapies.

It is naive and potentially harmful to believe that 25 mcg of L-T3 (Liothyronine) is equivalent to 100 mcg of L-T4 (Levothyroxine) at every dose and in every combination and in every patient.

The bulk of historical clinical research and practice disagreed with limiting L-T3 to such a low dose equivalent.

They raised the ceiling — they gave much higher doses and ranges to L-T3.


Wired123 profile image
Wired123 in reply to shaws

Well I’m still on T4 as well and pretty much on the same dose as I was prior to starting T3.

On T3 only, 20mg daily I think, I put on three stone in two years, mostly round my middle, with no lifestyle changes that would account for it. The endocrinologist and his specialist dietitian were baffled. I was then unmedicated for about nine months, during which time my weight was stable.

Wired123 profile image
Wired123 in reply to Ansteynomad

Yes mine is almost all around the middle.


Yes, agree cortisol could have something to do with your weight gain and change in body shape ... fat around the middle? Equally leptin, insulin, sex hormones , or all of them influencing metabolism & body fat distribution.

Leptin is secreted as weight is gained to signal to the hypothalamus there is enough energy (fat) stores. The hypothalamus then stimulates metabolic processes that result in a reduction in hunger, increased resting metabolism and lipolysis (fat breakdown) & so weight loss. Resistance to leptin is sensed as 'starvation' & all processes reverse to increase or retain fat stores. This includes changes to the deiodinase enzymes that dictates how our body uses our thyroid meds (same as happens on a calorie deficient diet or anorexia).

Much like blood glucose mechanisms going wrong with insulin, leptin can also work both ways - with high levels creating a down regulation of receptors after prolonged exposure to excessive levels, or simply inadequate levels. With glucose the issues are hypoglycemia (too little sugar in the blood caused by various reasons but in Hashi peeps mainly insufficient cortisol to raise blood sugar into the normal range) and insulin resistance (too much sugar in the blood mainly caused by eating too much chocolate 😁).

Then looking at cortisol when its elevated for too long in the early stages of hypo before we crash, it can cause thyroid hormone receptor insensitivity meaning T3 (active calorie burning hormone) won’t work effectively on a cellular level. Do you have other lingering hypo symptoms?

And finally low testosterone levels caused by previous low thyroid hormone or adequate testosterone where symptoms are still lagging behind good biochemistry could mean increased weight gain & belly fat caused by the resulting reduction in muscle mass and so calorie expenditure.

Why did this all happen after medicating T3 and not before? I have no idea 🤣 but after I started medicating T3 I blossomed physically (except for a few blood sugar issues that were rectified by frequent small meals that included protein at each) but suffered mentally until supplementing sex hormones. It’s as if adding T3 exposes any extreme deficiencies or systems that haven’t quite recovered, until they do 😁

Are you still hungry after eating?

Steni profile image
Steni in reply to radd

Amazing - thank you for this

Wired123 profile image
Wired123 in reply to radd

Very interesting points you raise.

Agree on lack of cortisol due to Hashis causing the knock on effect of not being able to raise sugars = cravings for sugar.

Didn’t realise adding in T3 will show up other problems. Are you taking Testosterone replacement as mine is borderline low coupled with low SHBG but this is not a new problem, it was there before I added in T3.

radd profile image
radd in reply to Wired123


No, I am a female who had elevated testosterone relative to O & P after diagnosis, so eventually took HRT as didn’t want a hairy chin! Also, good for post menopausal bone maintenence.

Both SHBG & testosterone should rise with optimal thyroid hormone levels but you need to go slow with T3 if supplementing testosterone because otherwise SHBG risks becoming elevated (ie in relation to sex hormones so binding too much. Most circulating testosterone is bound to SHBG but it also binds T3.)

Low testosterone in hypo males is common. Also blood sugar issues can suppress testosterone levels, hence males with diabetes usually have lower than normal testosterone levels, and low SHBG is a biomarker of insulin resistance and metabolic syndrome (low T3). Are you supplementing any liver helpers such as milk thistle? So much happens there.

Wired123 profile image
Wired123 in reply to radd

Your detailed and precise knowledge astounds me! Are you a doctor/scientist?

I’m not supplementing Testosterone and am just inside the range so it’s not indicated but I am borderline.

It’s a chicken and egg game really isn’t it. From your post I see you’re saying metabolic syndrome leads to low T3, but then adding too much T3 can lead to insulin resistance.

Will discuss liver helpers, you’re right that a lot happens in the liver and obesity can lead to a fatty and/or sluggish liver with knock on effects especially alright blood sugar levels.

It’s a real shame that Endos don’t look at the whole picture and the interaction between each hormone, just blindly tinkering with one thing at a time. If Endos don’t look at this then you wonder who will, they are supposed to be experts in hormones!

radd profile image
radd in reply to Wired123


Thank you, I am just another Hashi sufferer, but who is inquisitive & reads rather a lot 🤣.

No, I am not saying 'metabolic syndrome leads to low T3, but then adding too much T3 can lead to insulin resistance' (although I guess theoretically it could) but was trying to demonstrate how low SHBG corresponds with low T3, which blood sugar issues are known to be a result of. If GP’s also noted SHBG levels instead of just being guided by the TSH, we would all be a lot better off.

I can’t see that you have posted any blood test results & are on quite a small dose of T3. Be wary of a doctors ‘normal’ but if thyroid hormones, iron & nutrients are adequate then this will help any blood sugar issues to rectify. Like I said smaller more frequent meals including protein with each (& protein shake snacks in-between) rectified mine & my "hypo' weight fell off.

Other symptoms can lag behind good biochemistry as there are so many systems that have to catch-up. Again doctors don't recognise anything other than the six week duration between dose adjustments and retesting.

Wired123 profile image
Wired123 in reply to radd

It’s interesting that I’m seeing Harley Street private Endos and their knowledge is lacking vs well versed members on this forum like yourself.

I’ve been told by a Professor of Endocrinology that nothing can be done about low SHBG except if I go and lose weight. Yeah thanks mate, great advice when I have no energy!

This small regular meals may be the silver bullet I’m looking for. For too long I’ve been trying the approach of no snacks and sticking to 3 set meals which is what most weight loss advice centres around, but blood sugar can then crash/deviate too much and lead to binges and spiralling.

My previous results are on this old post:


Latest results will be posted as soon as I have them tomorrow/Monday.

My T4 levels were always high on Levo and I'm naturally thin. It's the only way I could function on it but I still had a TSH of 1.3 along with lingering hypo symptoms. Adding a small amount of T3 to high T4 levels actually makes my fluid retention and symptoms worse. My stomach bloated up. A few days ago I lowered my Levo a little bit and taking 15mcg of T3 with it. In those two days the swelling and fluid retention has reduced. Maybe it's not so much the T3 but the ratio of T4 to T3 and the conversion process or T3 causing T4 to be used up faster. Perhaps you need to slightly lower the T4 and raise the T3 a little. The advice on this forum to get the T4 around 60-70% has worked for me at the moment. So, if your T4 levels are high and that's what you need to function on Levo but then you add in a little T3 and that reduces the amount of T4 then you may be experiencing hypo symptoms which is raising your cortisol and creating body changes. That's what happens to me so I've had to lower my Levo a little and increase the T3 to compensate and with the amount of T3 I need to compensate I would feel terrible if I added that to already high T4 levels. I tried T3 only and didn't have body changes so I think it's more about the ratio of T4 to T3. I don't know the science behind all of it but this has been my personal experience. I'm still on my own journey to find the right combo and haven't been especially patient in the past several months until now because I'm not going back to T4 only. Hope you make some progress.

radd profile image
radd in reply to jrbarnes


I agree the ratio is hugely important and individual to everyone of us. If you read how the deidonases work they demonstrate how too much of one hormone will down regulate one system but increase another, etc, etc ... and more is certainly not always better.

For those of us that need to medicate both hormone meds even the conversion process is important as sets off other mechanisms at play in the whole picture of thyroid physiology.

And then even more tricky is factoring in all the conditions that low thyroid hormone induces such as inflammation, low stomach acid, etc, etc as all these have so much bearing on how meds will perform also.

Jonathan1956 profile image
Jonathan1956 in reply to radd

Hello radd, many thanks for your interesting comments. Interestingly, and counterintuitively, my wife lost weight (from size 12 to size 8) when hypo and undermedicated. Our functional doctor recommended 2 tbsps apple cider vinegar, dissolved in water, before meals, and her weight has now stabilized. I've noticed that she has a better appetite and quite often asks for a sandwich mid-afternoon. My wife is now doing well on 3.25 grains NDT/day, and we are, at long last, in the ball-park of optimum dosage. You have opened my eyes - weight gain/loss in hypo sufferers is much more complex than I imagined.

Wired123 - this may be a long shot, but my wife did not get on with the synthetic T3/T4 and has done much better on NDT. Just a thought?

shaws profile image
shawsAdministrator in reply to Jonathan1956

If you want to draw the attention of a member put an @ sign before their name and this is an example @ before the name. Several names may appear but when you select the name of the person you want he/she will then be notified as you will also notice it changes to blue, i.e. Jonathan1956

Hi just to let you know I trialled addingT3 to my T4 last year at aloe level and slowly increasing and I did generally feel better but it gave me headaches so after a year of persevering I’ve gone a I to T4. I also noticed I put on weight so much easier on the T3 even when not eating any differently. People assume it’s because you must be eating more but I definitely wasn’t. Since I e stopped the T3 weight has gone back to normal. I have read other people experiencing the same. It’s very strange!

Yes, I gained weight when I added T3, headaches, insomnia..off it now but still can't shift weight but at least I feel better. What I have noticed that I don't get hungry, ever!!!! Eat very little and very healthily.

Elevated cortisol is not condusive to weight loss. That is my experience. Body is too stressed

What brands of levo and lio are you taking?

All you have to do is type in google 'T3 and weight gain' you will get all the results ......Taking too much T3 can raise insulin resistance. In other words, thyroid hormone dose increases could lead to weight gain in those who are already insulin resistant. If this is the case, then diet modifications instead of higher doses are the solution. It has been found that not everyone will put on weight with T3....only those that are insulin resistant

It's strange because some people useT3 as it increases metabolism so can be abused quite easily so it's odd ur gaining weight with it sorry can't be more helpful


I am female but I have definitely put on weight with T3. It's strange though as it almost feels like predominantly fluid as sometimes I can push my skin and leave a dent and that has not been the case when being three stone heavier than this following pregnancy. Also it doesn't really apply to you but T3 has definitely altered my female hormones so my menstrual cycle is much shorter and my breast are bigger than ever, despite never really changing in size even when I was quite ill some years ago and 5 Stone lighter with severe acid reflux for a couple of years. I don't know the science behind it. No matter my weight they did not changes in size so it is a negative side effect of T3 for me.

Whether it is water or mucin or a different kind of fat I don't know. However, if miss a couple of doses of medication I notice a reduction in feeling full of fluid and the scale drops buy a couple of pounds. However, I bearly existed on T4 only so even with the side effects,T3 gives me some semblance of a normal life so I just reluctantly accept it. All hormonal systems are interlinked so it may be impacting on your male reproductive hormones.

Have you looked at your b12 level? My B12 level was low but in range. Improving this in my case with injections and going gluten free has made a massive difference. Blood levels of thyroid hormones only show whats circulating in the blood stream. It doesnt show what uptake there is in the cells . This means you can have high level on a blood test but you maybe not utlisung it very well. One way of addressing this is ensuring the other vitamins and minerals are optimal.

Have you tried taking all your T3 in once dose? Bar the weight gain do you otherwise feel optimum?

Can’t say I’ve gained weight on T3, but if I over do exercise I think I run out of T3; I feel hunger and eat more; so can put weight on.

You say your diet hasn’t changed but are you really eating in a calorie deficit? Regardless of what meds we take, if you’re not eating in a deficit you will gain weight (unless you’re under medicated which your bloods show you aren’t, unless the T3 isn’t really getting through on a cellular level - see question about taking it all at once).

Weight gain could also be due to an underlying digestive issue - perhaps a reaction Gluten or diary or soy; I’ve found my body started working properly on T3 and as such don’t eat gluten anymore and struggle with soya.

When you get your bloods done later this week, ask them to check testosterone and oestrogen for you too. I suspect you may have a sex hormone imbalance going on due to the extra T3. Just a theory, but I'm struggling with menopause and so I'm up to date on my knowledge there and think it is worth you investigating. Especially as it's around the middle you have gained it. Typical with sex hormone issues. I need more oestrogen to feel good in my brain, but I've had to reduce it again because when I have enough to feel good inside my head, I am so full of fluid I can't walk. As soon as I drop the oestrogen dose the misery returns and I loose the ability to multitask or think properly but the fluid in my feet goes down a bit. Everything is linked in this game.

I have gained a dress size since Christmas, when I started adding T3. So far I have had 2 or possibly 3 good days on it. The rest I feel as rubbish as before. Currently feeling very depressed. All I want to do is eat and it's about all I have been doing, especially carbs. So it could be hormonal gain for me or it could just be the crappy eating. I can barely function in the day. I'm glued to chairs. I'm not doing anything. Even the washing (with a machine and dryer) is too hard. I can't remember when I last felt this exhausted. I used to be up until 2am most nights. Now I'm falling asleep at 11pm. But I am waking up earlier and feel better for a little while on rising.

Like you I am retesting this week. Last test showed below middle of range T3 and T4. I feel like a lot of my gain is water. My skin, feet and stomach feel stuffed with it. It's horrible. Earlier in the year, I reached a point where I was loosing some of that mucin water and could finally start to almost pinch some skin (not been able to do that for many years) but that's reverted again. Very difficult to grasp any skin on my arms.

I think I'm going to be as interested in your results as in my own! I'm on 125 Levo and 20 T3. I'm 5'10". I experimented this last time since dose change (which means this coming blood test had to be delayed for me to get back stable again!). I tried reducing my Levo to 100mcg because it has never helped me and I've never felt good on it. I was OK for a few days then fast became not OK and my hair just jumped off my head! I would be sitting at my desk with it falling off around me. I have really thin hair on the top/front of my head now. I'm distraught about that. I reversed back to 125mcg Levo after 2 weeks. I have never been able to increase Levo over 125. It makes me feel really strange if I try.

Are you on progesterone as well? Like you, I need a high dose of estrogen to function. It was recently suggested to me that I should switch from cyclic to continuous HRT and that made a huge difference to me. I especially notice losing more fluid since taking progesterone daily instead of two weeks a month.

I've been on continuous HRT for several years now. I have the Mirena coil for progesterone. It works better than the tablets or capsules for me.

I kind of have experienced the same, even though I'm still very slender I have a weird accumulation of body fat around my middle (; I'm on T3 only 3 times daily 25 mcg. I also have many other symptoms like a extreme histamine intolerance, leaky gut (yes, I'm avoiding all the inflammatory stuff, I only eat organic beef, cucumber and mango for some years now...), anxiety and chronic lyme :/ Maybe to much T3 is making things worse?I'm female...

Has anyone experience with lowering the dose?

I’ve just come across this interesting question and it may be a light bulb moment for me. I’ve been taking NDT for 1 years and then T 3 for 4 years. Whilst I feel pretty good on T3 with energy levels etc.. my weight has climbed by 3 stone within 5 years. I’ve always watched my good nutritional intake and regularly exercise. Yes I.m female and in my early 50’s so hormone changes are at play. However, I am so frustrated and upset by the weight gain and have tried to research and understand why ? Since I started NDT then 20 mcg T3 the weight keeps on growing. I’m due to have bloods before endo appointment within 3 weeks and will definitely ask about possible weight gain on T3 as I feel incredibly bloated and unhealthy. Thank you for raising this.

You are at prime time for your bloating and weight gain to be loss of oestrogen rather than your T3. We gain weight at menopause and during late perimenopause when our hormones are all over the place. It's a common misconception that HRT makes you fat. It's not, HRT often gives us more energy to exercise and stay or reduce weight. But menopause changes cause weight gain, especially around the middle. We loose fat off our thighs and bums and gain it on our stomaches.

Hi Wired123

T3 will boost your cortisol levels - See Paul Robinson's work with the CT3M. If your cortisol was low then having it increased courtesy of the T3 is a good thing especially if you find you can wake up in the morning more easily and function better.

From what I understand increased cortisol can lead to weight gain - see this blog


Apologies that it is written from a female perspective, but if you scroll down to the section on diet and blood sugar regulation there is some reasonably good advice there. You say you haven't changed your diet - perhaps you might need to make some changes to accommodate your higher cortisol levels, eating more fruit and veg, higher fibre foods, and less refined carbs and perhaps lower your carb intake. I am in a similar position as I am taking Adrenal Cortex Extract to boost my low cortisol levels and am also on T3 and am noticing some subtle weight changes and an having to moderate my eating accordingly - more protein and vastly reduced carbs.

Hi Wired123, When you say your shape has changed how much weight have you gained and what type of change? I did gain a lot of weight after my thyroidectomy and I use to be a fitness instructor and extremely active but for me personally I don’t blame my gain on T3 but on the surgery and aftercare that sucked so bad my TSH was allowed to go high for weeks before my original moron Endo would even give me meds and I fell apart from their.

Wired123 profile image
Wired123 in reply to Batty1

I’ve put on a stone since adding T3. I still have a thyroid gland but it’s badly damaged due to Hashi’s.

Hi Wired123 I am a 63 year old female and I have been gaining weight steadily for the last few months - around my middle but sitting more on the sides. I had not considered it could be connected to when I started a T4/T3 combination last September so you have raised a very interesting point, thank you. My doses of T3 had not been consistent as I had a bad start and I then had a kidney infection which lasted over a month in the middle of it all which made everything go awry - so the last four months have been on a consistent dose (125mcg Levo x five days, 100mcg x two days and 6.25mcg Lio every day. I am now getting very concerned with this gradual weight gain and I have had other hypo symptoms creeping back so I think it may well be thyroid hormone-related, rather than something else. I am about to post to ask for advice as both my T4 and T3 are high and I just don't know what to do next. jrbarnes post about ratios of T4 to T3 was helpful too and I think reducing my T4 and increasing my T3 may be the way forward. I hope you get some helpful advice from your Endo and will look out for your next post.

jrbarnes profile image
jrbarnes in reply to Zebra5

I got that good advice from the admins and other members here. Perhaps trying to alternate three days with a lower dose plus raising the T3 will help. It certainly made life more tolerable for me!

Zebra5 profile image
Zebra5 in reply to jrbarnes

Thank you fur your help jrbarnes I think I will do that. I’ll start a new post with my blood test results as would like some guidance on vitamins too x

Get your igf-1 checked. T3 raises it and can lead to insulin resistance.

Thanks, this has been done and awaiting results. Will post back when I have them

I had to persist for nearly 10 years to be given T3 as my then consultant said I couldn't have it....I thanked him for his tunnel visioned services and asked to see another consultant who was much more helpful but he was not keen on T3 either. He explained that it was little understood, but I wanted to try it. As my Thyroid was unstable (hyper one day, hypo the next) I got impatient after a few months and kept changing my meds which did little to help my cause I know, but I was so exhausted all the time. My GP suggested diet and exercise too, so I suggested she review my notes and when she did realised that as a Persona Fitness Trainer I had a pretty good handle on the whole diet and exercise thing already. Joke eh? My Thyroid consultant retired and a new guy saw mw who was more than happy to write me prescription for T3...and off I went. I had at alarm more energy but nothing like the energy I had before so I had to give. up my25 year career as a PT because some mornings I couldn't;t get my head off the pillow. I put on weight, but I honestly don't know if the T3 is responsible as I lost weight in the first year. age does have a bearing on everything I'm afraid, and as I; ve got older it's crept on despite having a physical job and being generally active. Food intolerances can cause us to gain weight - fluid retention in particular - I live abroad at the moment so haven't been able to see my specialist since Dec 2019, in France they don't even have T3 so I get mine sent over until I can get home. Have you seen any research to support your suspicions? as I would be very interested to see it.

Started daily dose of 10mcg t3 in January 2019. Gradually increased to 60mcg. No Levo. Had previously gained 2st 10lb on top of 8st over previous 15 years and feeling like hell. Now lost over half of weight gain without trying. So, no, I didn’t gain on t3. It’s sped up my metabolism as suggested it would. So maybe it’s the cortisol. Hope you sort it soon.

Wired123 profile image
Wired123 in reply to Kandahar

Big difference is you are on T3 mono, I’m on T3/T4 combo. Mono is the next option I’m considering and it’s pleasing to see it worked so well for you!

Kandahar profile image
Kandahar in reply to Wired123

Don’t understand the difference. Perhaps you should stop levo?!

Add some ashwgandha 400-500 mg on daily basis,cortisol will be refuced.and thyroid function will be much better.

Wired123 profile image
Wired123 in reply to Irshassd

Well I need the additional cortisol in the morning to wake up which is what T3 gave me. I’ve tried Ashwa before adding T3 and it actually made me more tired!

Will try getting a 24 hour urinary cortisol and see what that shows as well as perhaps the salivary cortisol curve.

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