I’ve got a good question for discussion that could probably help a lot of ppl out. I’ve read about and heard a lot of different ppl talk about T3 only therapy. I’ve experimented with it and never been able to handle the doses recommend by ppl. I’d love to read or hear someone elaborate on how to approach using T3 for ppl that are sensitive. I know I’m not the only one out here with this issue. There’s a lot of us. What are the reasons one individual could handle 25mcg daily and someone else can only handle 1mcg daily? I’ve always wondered this as most T3 medications are dosed fairly high - or at least way higher than I could handle in a single serving. Even Idealabs - 1 drop is 8mcg. If I used one drop I’d prob feel like I was having a heart attack lol. What is it that the T3 sensitive population lack or have excess of? What do we need to look at from a testing/biomarker standpoint? Cortisol levels? Nervous system dominance? Tissue sensitivity to T3? HPA axis disregulation? I’d love someone to actually go into depth on this subject.
Personally, ive only been able to use 1-2mcg at a time max and ive spread that dose out through the day. I’ve also tried using T3 (at the same dose) with food only as others have recommended. And I’ve tried lower doses (0.5 mcg) with the same protocols. It’s always made me feel the same - anxious, in sympathetic overdrive, foggy/spaced out, given me ruminating thoughts, wired but tired, etc. It’s never been an enjoyable experience for me and I’ve always stopped a week or so into using it.
Most recently I tried using T3 to further optimize my thyroid levels. My most recent labs showed TSH = 4.15, Free T4 = 1.2, Free T3 = 3.5, T3 Uptake = 32, Reverse T3 = 12. I was interested in lowering TSH & raising free t3. Using 1 mcg with breakfast, lunch and dinner. I made it a week and a half and had to stop.
Anyways - just something I’ve always wondered about and never seen anyone go into depth on explaining. Maybe a subject worthy of a future article.
If you convert T4 into T3 adequately, the you can also take T4. Then T4 only might actually work. Otherwise I like TyroMix and use that throughout the day. Keep an eye on your heart rate and body temp, sleep and energy.
I have Thybon 20 as a private prescription through connections. It is German pharmaceutical-grade T3 (Liothyronine) from Sanofi.
A few months ago, because of what I considered suboptimal T3 levels, I started experimenting very cautiously with only 2.5 mcg (1/8 tablet). Splitting the tablet into exact eighths is honestly quite annoying and inconsistent.
Unfortunately, I mostly notice negative effects from it:
increased pressure sensation in my head
a more visible/prominent vein on my head
brief warmth shortly after taking it
but then I quickly feel cold again
increased inner tension, nervousness and overstimulation
At one point I tried to work up to 3×2.5 mcg per day, but the symptoms stayed the same, so I did not continue increasing the dose.
I also have the impression that T3 amplifies the “high stress / adrenaline mode” that I already seem to live in most of the time. Instead of feeling calmly energized, I feel more wired, overstimulated and adrenergic.
This makes me wonder whether my issue is truly a lack of T3, or whether my body is already in a chronically sympathetic / stress-driven state and additional T3 is just increasing catecholamine sensitivity further.
My reaction feels less like “better metabolism” and more like:
wired but tired
overstimulated but not truly energized
transient warmth followed by coldness again
more sympathetic activation rather than calm metabolic energy
For context, I also deal with chronic stress, nervous system dysregulation, sleep/recovery issues (can easily fall asleep and stay asleep but never feel refreshed), dysbiosis of the colon, SIBO (IMO) with low motility, and periods of caloric restriction/recomp dieting. I know I need to continue working on the gut/motility side of things and finally get rid of SIBO, but I wanted to mention this as additional context because I suspect it may contribute to the overall stress physiology picture as well.
Because of this, I wanted to ask:
Why do you think I react this way to T3?
And would you personally recommend pursuing a different route instead of continuing to increase T3?
Do you think it could make sense to instead try breaking the 2.5 mcg dose down into even smaller divided doses across the day and just hold that steady for a while to observe adaptation/tolerance?
For example, something like splitting 2.5 mcg into 3 very small doses throughout the day to avoid a stronger adrenergic peak response.
The problem is that with Thybon tablets this becomes quite impractical and not always very reproducible dosing-wise, especially at such tiny amounts.
I originally experimented with Thybon because my free T3 values seemed relatively low/suboptimal. Here are my thyroid labs chronologically with their respective reference ranges:
01.03.2024
TSH: 1.71 mU/L (ref. 0.27–4.2)
Free T3: 2.6 pg/mL (ref. 2.00–4.43)
Free T4: 1.5 ng/dL (ref. 0.93–1.7)
Reverse T3: 0.14 ng/mL (ref. 0.12–0.35)
20.06.2024
TSH: 2.9 µIU/mL (ref. 0.27–4.2)
Free T3: 3.17 pg/mL (ref. 2.0–4.4)
Free T4: 1.31 ng/dL (ref. 0.9–2.0)
03.06.2025
TSH: 3.51 µIU/mL (ref. 0.27–4.2)
Free T3: 2.74 pg/mL (ref. 2–4.4)
Free T4: 1.46 ng/dL (ref. 0.9–2.0)
Reverse T3: 0.15 ng/mL (ref. 0.12–0.35)
DHEA-S: 340 µg/dL (ref. 160–449)
Cortisol: 204 ng/mL (ref. 20–200)
I would really appreciate your interpretation of these labs and whether you think this truly points toward a functional T3/conversion issue, or whether the bigger issue may instead be stress physiology, under-recovery, inflammation/endotoxin burden, gut dysfunction, etc.
Where to buy t3?
I’ve got a good question for discussion that could probably help a lot of ppl out. I’ve read about and heard a lot of different ppl talk about T3 only therapy. I’ve experimented with it and never been able to handle the doses recommend by ppl. I’d love to read or hear someone elaborate on how to approach using T3 for ppl that are sensitive. I know I’m not the only one out here with this issue. There’s a lot of us. What are the reasons one individual could handle 25mcg daily and someone else can only handle 1mcg daily? I’ve always wondered this as most T3 medications are dosed fairly high - or at least way higher than I could handle in a single serving. Even Idealabs - 1 drop is 8mcg. If I used one drop I’d prob feel like I was having a heart attack lol. What is it that the T3 sensitive population lack or have excess of? What do we need to look at from a testing/biomarker standpoint? Cortisol levels? Nervous system dominance? Tissue sensitivity to T3? HPA axis disregulation? I’d love someone to actually go into depth on this subject.
Personally, ive only been able to use 1-2mcg at a time max and ive spread that dose out through the day. I’ve also tried using T3 (at the same dose) with food only as others have recommended. And I’ve tried lower doses (0.5 mcg) with the same protocols. It’s always made me feel the same - anxious, in sympathetic overdrive, foggy/spaced out, given me ruminating thoughts, wired but tired, etc. It’s never been an enjoyable experience for me and I’ve always stopped a week or so into using it.
Most recently I tried using T3 to further optimize my thyroid levels. My most recent labs showed TSH = 4.15, Free T4 = 1.2, Free T3 = 3.5, T3 Uptake = 32, Reverse T3 = 12. I was interested in lowering TSH & raising free t3. Using 1 mcg with breakfast, lunch and dinner. I made it a week and a half and had to stop.
Anyways - just something I’ve always wondered about and never seen anyone go into depth on explaining. Maybe a subject worthy of a future article.
Same here!
So how do you figure out dosing? And should you always also take T4 with it or just T3 is ok?
If you convert T4 into T3 adequately, the you can also take T4. Then T4 only might actually work. Otherwise I like TyroMix and use that throughout the day. Keep an eye on your heart rate and body temp, sleep and energy.
@Hans Do take a look,might be good for ya podcast
If basal body temp is sitting just under 97 and thyroid labs are as so are you still pulling synthetic T3?
TSH: 2.59
T4, Total: 7.5
T4, Free: 1.3
T3, Free: 3.1
T3 Total: 103
T3 Reverse: 12
Thyroglobulin Antibodies: <1
Thyroid Peroxidase Antibodies: 7
Hi Hans,
I have Thybon 20 as a private prescription through connections. It is German pharmaceutical-grade T3 (Liothyronine) from Sanofi.
A few months ago, because of what I considered suboptimal T3 levels, I started experimenting very cautiously with only 2.5 mcg (1/8 tablet). Splitting the tablet into exact eighths is honestly quite annoying and inconsistent.
Unfortunately, I mostly notice negative effects from it:
increased pressure sensation in my head
a more visible/prominent vein on my head
brief warmth shortly after taking it
but then I quickly feel cold again
increased inner tension, nervousness and overstimulation
At one point I tried to work up to 3×2.5 mcg per day, but the symptoms stayed the same, so I did not continue increasing the dose.
I also have the impression that T3 amplifies the “high stress / adrenaline mode” that I already seem to live in most of the time. Instead of feeling calmly energized, I feel more wired, overstimulated and adrenergic.
This makes me wonder whether my issue is truly a lack of T3, or whether my body is already in a chronically sympathetic / stress-driven state and additional T3 is just increasing catecholamine sensitivity further.
My reaction feels less like “better metabolism” and more like:
wired but tired
overstimulated but not truly energized
transient warmth followed by coldness again
more sympathetic activation rather than calm metabolic energy
For context, I also deal with chronic stress, nervous system dysregulation, sleep/recovery issues (can easily fall asleep and stay asleep but never feel refreshed), dysbiosis of the colon, SIBO (IMO) with low motility, and periods of caloric restriction/recomp dieting. I know I need to continue working on the gut/motility side of things and finally get rid of SIBO, but I wanted to mention this as additional context because I suspect it may contribute to the overall stress physiology picture as well.
Because of this, I wanted to ask:
Why do you think I react this way to T3?
And would you personally recommend pursuing a different route instead of continuing to increase T3?
Do you think it could make sense to instead try breaking the 2.5 mcg dose down into even smaller divided doses across the day and just hold that steady for a while to observe adaptation/tolerance?
For example, something like splitting 2.5 mcg into 3 very small doses throughout the day to avoid a stronger adrenergic peak response.
The problem is that with Thybon tablets this becomes quite impractical and not always very reproducible dosing-wise, especially at such tiny amounts.
I originally experimented with Thybon because my free T3 values seemed relatively low/suboptimal. Here are my thyroid labs chronologically with their respective reference ranges:
01.03.2024
TSH: 1.71 mU/L (ref. 0.27–4.2)
Free T3: 2.6 pg/mL (ref. 2.00–4.43)
Free T4: 1.5 ng/dL (ref. 0.93–1.7)
Reverse T3: 0.14 ng/mL (ref. 0.12–0.35)
20.06.2024
TSH: 2.9 µIU/mL (ref. 0.27–4.2)
Free T3: 3.17 pg/mL (ref. 2.0–4.4)
Free T4: 1.31 ng/dL (ref. 0.9–2.0)
03.06.2025
TSH: 3.51 µIU/mL (ref. 0.27–4.2)
Free T3: 2.74 pg/mL (ref. 2–4.4)
Free T4: 1.46 ng/dL (ref. 0.9–2.0)
Reverse T3: 0.15 ng/mL (ref. 0.12–0.35)
DHEA-S: 340 µg/dL (ref. 160–449)
Cortisol: 204 ng/mL (ref. 20–200)
I would really appreciate your interpretation of these labs and whether you think this truly points toward a functional T3/conversion issue, or whether the bigger issue may instead be stress physiology, under-recovery, inflammation/endotoxin burden, gut dysfunction, etc.