My T4 was showing well above range with adequate T3 on 7th December and I decided to stay on this dosing and retest in the spring. I’ve ordered the test kit and suspect my results will be the same but let’s see. If this is the case, dropping the T4 without introducing T3 is NOT an option for me unless I want to be in bed all day. I know this from experience, got the T shirt etc.
My question is, how much more powerful is T3 than T4? So for example, if I wanted to try dropping my T4 by 12.5mcg……would the approx. dosing equivalent for T3 be 2.5mcg (5 times as potent)? I’m very sensitive to T3 so would not want to start any higher than this.
My other option will be to stay on out of range high T4. There is no other option if I’m to stay operable and will have to take the health risks on the chin.
My T4 was quite out of range in December (link below) so will be interesting to see if the T4 remains as elevated. I’ll know in a week or so when my test kit arrives etc.
Going on your last test your FT3 was at 76% of its range so I think you really do need to drop some levo to add in even a small amount of T3.
I think we are all individuals and although there are equivalence rates out there, in reality how we absorb and use thyroid hormone varies, even between brands for instance.
Generally speaking people on combination treatment end up on 100-125 Levo and 5-15mcgs T3.
Most important thing is to ensure your vitamin levels are all optimal before making the change as this will help you tolerate and use the T3 well.
Hi Jaydee, last time I had my vitamin results checked was 9 months ago but I really don’t think this is the issue plus I tweaked supplementation in response to the results and eat very healthily plus 100 per cent gluten free for many years.
I will get around to another full vitamin test soon just to check nothing needs tweaking such as vitamin D reduction etc but I think my issue is having to be on high T4 to be able to convert enough T3 naturally.
The information you have provided on typical T4/T3 dosing is very helpful! Thank you
That's not the right question to be asking because they're not the same thing.
T4 is basically a storage hormone that doesn't do very much until it is converted into the active hormone, T3. So, the equivalance of, say, 25 mcg T4 to T3 for you depends on how well you convert. And, that is difficult to quantify.
It is suggested that 25 mcg T4 is equal to 5 mcg T3, but I think that would be in someone who converts perfectly. However, if you need to take T3 it's usually because you don't convert perfectly. But, if your FT4 is high, and your FT3 low, then reducing levo by 25 mcg and adding in 5 mcg T3 is a good place to start, and you can adjust according to your needs at a later date, when you know how you react to that change. It's all trial and error.
In the blood T3 is 4 to 5 times as potent as T4 as regards its effect on supressing TSH. As tablets LT3 is 3 times as potent as T4 onlinelibrary.wiley.com/doi... .
The accepted conversion ratio when on T4 monotherapy is said to be 1 / 3.50 - 4.50 - T3/T4
with most people feeling at their best once their T4 is in the top quadrant of it's range as this then, should in theory, convert to a decent level of T3 with most people feeling at their best when they come in this ratio at 4 or under.
So to find how well you are converting the T4 - you simply divide your Free T3 result into your Free T4 result.
So looking at your previous readings - we have a 5.88 / 33.50 and more recently 5.90/29.40 and that looks to me like dropping some T4 your conversion actually went up :
Your first shows conversion at 5.69 and on a reduced dose of T4 - I'm getting a 4.98 :
So, the potency of T3 to T4 is unique to each individual as to how well they convert thyroid hormones - there is no direct comparison but rule of thumb seems to be around 4 or under.
The original and successfully used treatment for over 100 years for hypothyroidism is Natural Desiccated Thyroid which contains all same known hormones as that of the human gland and derived from pig thyroids dried and ground down into tablets referred to as grains.
The ratio of T3/T4 in NDT is around 1/4 with Armour being the most well known brand and 1 grain of Armour contains 9mcg T3 + 38 mcg T4 :
There are however some people who add a little T3 or T4 to their NDT to find their sweet spot - I can't say I've ever found my sweet spot - but then I had RAI thyroid ablation back in 2005 and haven't a thyroid.
When T4 monotherapy failed to restore my health and well being the NHS refused me both T3 and NDT so I had to do things for myself and currently 5 years in on NDT I'm ok on this full spectrum thyroid hormone replacement.
perhaps my reply here should be done as a general one, but I must say that your post and others seem to see T3 as some sort of cure-all that’s fashionable as well. It’s not. And you don’t need itat all if you are already converting t4 to t3.
I was fine on 125mcg Levo a day for many years. It was only later that I failed to convert and was prescribed t3.
So, my question is how do you FEEL? That is the overriding point.
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