T4/T3 Combo Synthetic Vs NDT choice


Wonder if anyone can advise . Been on T4 only now for 2 years with no improvement or worsening hypo symptoms . Fluctuating between 100mg and 75mg due to TSH led diagnosis . Have finally got to see an been pushing endo to trial combo T4/T3 and he is considering but won't yet say for sure. However most success stories I have read revolve around NDT. I have found a doctor who is willing to prescribe NDT . Has anyone had experience of combo synthetic T3/T4 success vs NDT. I am desperate now to do something different and don't want to waste another year under an endo if T3/T4 is not as effective as NDT. On the other hand having waited almost 6 months to even see an Endo, I don't know whether I should still seek to try adding T3 to my current T4 first. But I feel my Endo is too slow to react and will always measure me on TSH . My main symptoms at moment are is weight gain, hair loss, debilitating fatigue plus all the usual list. (I do take full nutrition supplements and vitamins )Any advice would be most welcome . Thank you

16 Replies

It's not as simple as that, I'm afraid, because we're all individuals, and all react differently to different treatments. Whilst one person might do very well on NDT, another might find it makes her worse. And, to add to the confusion, there are lots of different brands of NDT, and you might have to try several different ones, before you find the right one for you.

I started on T4 only, and did very badly. I did a little better on T4+T3. On NDT, I went rapidly downhill and was worse than on T4 only. I tried several different brands, but none of the suited me. I finally found that I needed T3 only.

In the same way, you are going to have to find what works for you. No-one can predict which will be best for you. You just have to try it and see, I'm afraid. It's all trial and error.


It's a very individual thing. Some people do well on synthetic T4+T3 combination but don't do well on NDT and vice versa. No way of telling unless you try both. I do well on T4+T3 so I've never tried NDT.

Whatever you try, having dose guided by TSH will often mean your FT4 and FT3 are not optimal and you won't feel well. Read Treatment Options in thyroiduk.org.uk/tuk/about_... Email louise.roberts@thyroiduk.org.uk if you would like a copy of the Pulse article to show your endo.

As greygoose states. It isn't as simple as that as our bodies accept medications/hormones differently.

If I were you I'd try NDT first as that was the very original and it does contain all of the hormones we'd produce if our gland was healthy. There are several varieties and you might have to try one or two but might be very lucky and respond straight away to your first choice.

You need to put up a new post when you decide of where you can source your choice and for a Private Message to be sent to you with information.

I've tried T4 and t3 and felt better than just being on Levo alone. My weight stabilised but I still couldn't sort the fatigue though. I stuck at it for a year or two until my Endo said he'd be happy to trial me on Nature Throid. Have been on this for 2 months and it's definitely helped me with the fatigue though not fully. This is the best I've felt since being diagnosed some 5-6 years ago. I'm just waiting for my bloods to come back to see if they back up how I'm feeling. Best of luck on your journey to feeling well again.

Thank you all for your replies. Its very much appreciated.

If you have Hashimotos, Izabella Wentz, on Thyroid Pharmacist website, suggests that T3/T4 combo is possibly likely to suit better than NDT

I am about to try adding T3. I decided on that as first option as I take my T4 at bedtime, which I found much better than mornings & didn't want to change.

I've got Hashimoto's. I'd been on t4 for the past 6yrs and still experienced symptoms. I didn't even know NDT or t3 existed until about two months ago, I blindly trusted my gp's. I added 6.25 mg per day, five days ago. Today, for the first time in months my arms aren't aching as much. I'm hoping this is due to the t3, as when my private blood test results came back, my t3 was only just above the lowest level. It's early days for me, but I can honestly say that without this group and one on Facebook, I'd still be completely in the dark about other options to treat myself, struggling every day. I really hope t3 will prove to be my saviour and hope you find yours ☺

Hi Bejourain,

I have some T3 also to add to my synthroid. I'm afraid of negative side effects like anxiety and insomnia. Have you experienced any of these symptoms? Is your fatigue better?

Thank You,


It's early days for me, I started last week and some of my vita min levels were low, so I'm onky two weeks into supplementing them. The only thing I've noticed, is that my arms aren't aching as much. They've been aching for months now. It was so bad a few weeks ago, it was painful to pick a cup of coffee up, how pathetic is that? It's not affected my sleep.

Thank you SlowDragon. Bijourain, sorry to hear you have struggled so long in the dark. Once I started reading up on this I was shocked at the sheer numbers of people in the same situation as me and astounded at the ignorance or dismissiveness of the mainstream medical profession. Wishing you luck on the T3.

You must make sure vitamin D, folate, ferritin and B12 are at very good levels. Don't just accept "normal" as a result. Get a printed copy, including ranges & post on here for advice.

If have high antibodies (Hashimotos) then getting to grips with that too. Very many of us find strictly gluten free reduces symptoms enormously & can also lower TPO antibodies

Hashimotos often impacts on gut function, improving gut bacteria can help -kefir, sauerkraut and good daily probiotic

Soya best avoided

As far as I can tell it The British Thyroid Foundation who tell the NHS that t4 is the preferred treatment. We need to change this mindset, I wonder if anyone there has thyroid disease, and if they do, what treatment they receive? Good luck to you too 🖒

This suggests they do acknowledge some need T3

It's written for endocrinologists mainly to highlight that patients should NOT be having T3 withdrawn on grounds of cost


So why has somebody else posted on here with a response from their gp, stating that Levothyroxine is their preferred choice? If i hadn't found this group I wouldn'thave found out that t3 or NDT was even an option as neither my gp or endo mentioned to to me.

Exactly- if you read my profile been to hell & back

Been completely stonewalled for 25 years.

The only endo who started to open up to me that they saw 100's (if not 1000's) of patients like me - she was quickly silenced.

Here's the BTA recommendation for GP's


There's two problems now

1 they won't acknowledge that some need T3 & it's more than a very few

2 NHS being ripped off on cost of T3, so rather than sort it, they are trying to withdraw it as an option

Meanwhile the cost in ruined lives & extensive testing for other causes is vast.

So I wonder what they are going to do when, people, who haven't received the correct treatment, turn up with heart failure, like my Mum, who ended up having a heart by pass, two kidneys removed and who basically slowly died a horrible death? They spent thousands on her treatment in the last two years of her life. I honestly don't think the NHS is fit for purpose.

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