Awful fatigue from thyroid?

[roguerain00]

This is my first post after lurking over a year but hoping I can get some advice. After losing about 32 lbs starting from Aug 2024-Late June 2025 I’ve noticed pretty rough fatigue , mid day waves of being exhausted, low motivation, etc. so Hypothyroid symptoms pretty much. These symptoms have worsened over time since starting this diet. Started sema in late January this year then later switched to tirz and now titrating down tirz as I add in reta to maintain as it felt tirz was increasing the fatigue. Was consistently eating under 1900 calories trying to push a 1 lb loss per week since Jan since my tdee was like 2100 at 5’8 after starting glp.

Posted my thyroid labs from this past week. The only previous time I tested my thyroid was back in 2021 and it was only tsh which was 1.3.

My primary doctor didn’t see this as an issue and would not refer me to an endo and pretty much dismissed my symptoms. Wondering where to go from here to get everything into optimal ranges ideally avoiding long term medication like t4 since this only became a problem after this deficit and I don’t believe I need it.

 

[HeatherSwanson]

Supplement with iodine and sea kelp, helps out a lot. Some people can get off synthroid with iodine.

 

[BigDadd7]

A one time snapshot of your thyroid isn't enough to diagnose fatigue. You could draw blood morning, noon ,and night on the same day and get different readings. It's no wonder your doc didnt give you a referral, those numbers don't warrant a referral. You've been on various glps and in a deficit for a while now. That's most likely the source of your fatigue.

 

[Ghoul]

TSH at that level accompanied by fatigue after significant weight loss are classic signs of subclinical hypothyroidism. Most primary care docs don't care about it, to be frank.

It's perfectly reasonable to try a trial of T4. You could start with 25mcg, see how you feel after a couple of weeks. If better, titrate to 50mcg. after a couple more
weeks check TSH. You're aiming to keep free T4 in normal range with TSH no lower than 1, on an max dose of thyroxine of about 1.6mcg/kg. Only use a reputable brand of thyroxine (Abbot, Glaxo Smith Kline).

 

[BamaCrazy]

Don’t jump on a prescription medication that your Doc hasn’t prescribed. As BigDadd7 mentioned above labs should be taken over time to determine if you really have thyroid issues. One lab out of range is not enough to diagnose anything.

My Wife has hypothyroidism and she had been feeling the same fatigue, plus body pain. At first the Doc was told her she likely has fibromyalgia or lupus. So we threw everything at it that has to do mitochondrial function.

1. NAD+
2. NMN
3. NR
4. Resveratol
5. Glutathione injections
6. Carnitine injections
7. 5-Amino 1MQ
8. Ubiquinol

After 3 days taking the above symptoms that she has been living with for months disappeared. And she has been good ever since.

Also look at your diet to ensure you are getting the calories and nutrients needed. Being in a caloric deficit can cause a lot of those issues also.

 

[Ghoul]

Don’t jump on a prescription medication that your Doc hasn’t prescribed. As BigDadd7 mentioned above labs should be taken over time to determine if you really have thyroid issues. One lab out of range is not enough to diagnose anything.

My Wife has hypothyroidism and she had been feeling the same fatigue, plus body pain. At first the Doc was told her she likely has fibromyalgia or lupus. So we threw everything at it that has to do mitochondrial function.

1. NAD+
2. NMN
3. NR
4. Resveratol
5. Glutathione injections
6. Carnitine injections
7. 5-Amino 1MQ
8. Ubiquinol

After 3 days taking the above symptoms that she has been living with for months disappeared. And she has been good ever since.

Also look at your diet to ensure you are getting the calories and nutrients needed. Being in a caloric deficit can cause a lot of those issues also.

As risky ugl lab produced T3 that thousands of members here routinely use you don't comment on?

Low dose thyroxine(T4) has a risk profile lower than the caffeine from one cup of coffee.

Don't be gaslit by this shithead and personal grievance driven selective pharmaceutical "caution".

The levels of TSH, normal ft4, accompanied by quality of life impacting symptoms falls squarely within medical guidelines for a trial dose of T4.

Bama is demented enough he'd rather see you needlessly suffer than me be right.

Your persistent symptoms and TSH levels clearly fall within the medical definition of subclinical hypothyroidism, and if trial low dose of T4 doesn't help, just drop it and look for another cause. It's not going to hurt you, which is more than can be said for countless PEDs used in abundance by the same guy swooping in to "save you", lol.

 

[wldb33rz]

This is my first post after lurking over a year but hoping I can get some advice. After losing about 32 lbs starting from Aug 2024-Late June 2025 I’ve noticed pretty rough fatigue , mid day waves of being exhausted, low motivation, etc. so Hypothyroid symptoms pretty much. These symptoms have worsened over time since starting this diet. Started sema in late January this year then later switched to tirz and now titrating down tirz as I add in reta to maintain as it felt tirz was increasing the fatigue. Was consistently eating under 1900 calories trying to push a 1 lb loss per week since Jan since my tdee was like 2100 at 5’8 after starting glp.

Do a carb load/refeed for a few days to a week. What's happening, based on your labs, is that your thyroid hormone receptors are being downregulated due to sustained lower calorie intake. This is why your T4 and T3 levels are actually quite good, but your TSH is high, although not outrageous but your RT3 is very high. The RT3 acts as an anti-T3 and works to knock it down. This is giving you the hypo symptoms and fatigue. The doc would see your labs and is likely not to refer you to an endo because this isnt a hormone issue, it's a body systems downregulation issue.

I've had to deal with this a few times on the GLP-1 treatments over the last 18 months and just finished a carb load/refeed last week. This will reset your body's demand for thyroid hormones and upregulate to normal function. Be extra careful during the refeed, keep it to around 2100-2200 max, based on your TDEE. You want to be at maintenance so your body isnt stressed and trying to downregulate energy expenditure.

Edit to add: during refeed, keep fats low, and increase carbs. Beans, rice, potatoes, even poptarts work, but generally want to keep your total fat down around 40g or less.

 

[Mrhairyman]

After losing about 32 lbs starting from Aug 2024-Late June 2025 I’ve noticed pretty rough fatigue , mid day waves of being exhausted, low motivation, etc.

How much weight did you lose before starting sema,Tirz,reta ?

 

[BamaCrazy]

As risky ugl lab produced T3 that thousands of members here routinely use you don't comment on?

Low dose thyroxine(T4) has a risk profile lower than the caffeine from one cup of coffee.

Don't be gaslit by this shithead and personal grievance driven selective pharmaceutical "caution".

The levels of TSH, normal ft4, accompanied by quality of life impacting symptoms falls squarely within medical guidelines for a trial dose of T4.

Bama is demented enough he'd rather see you needlessly suffer than me be right.

Your persistent symptoms and TSH levels clearly fall within the medical definition of subclinical hypothyroidism, and if trial low dose of T4 doesn't help, just drop it and look for another cause. It's not going to hurt you, which is more than can be said for countless PEDs used in abundance by the same guy swooping in to "save you", lol.

View attachment 338119

This idiot always recommends jumping on prescription drugs because he’s a moron. He uses AI to spit out word vomit on a daily basis when in reality he’s truly stupid and cannot form a coherent thought without help. He was picked on as a child and made to feel ignorant. ChatGPT is finally his opportunity to show everyone how artificially smart he is.

He is not a doctor, has no medical degree, but feels the need to prescribe prescriptions to complete strangers on the internet.

 

[roguerain00]

As risky ugl lab produced T3 that thousands of members here routinely use you don't comment on?

Low dose thyroxine(T4) has a risk profile lower than the caffeine from one cup of coffee.

Don't be gaslit by this shithead and personal grievance driven selective pharmaceutical "caution".

The levels of TSH, normal ft4, accompanied by quality of life impacting symptoms falls squarely within medical guidelines for a trial dose of T4.

Bama is demented enough he'd rather see you needlessly suffer than me be right.

Your persistent symptoms and TSH levels clearly fall within the medical definition of subclinical hypothyroidism, and if trial low dose of T4 doesn't help, just drop it and look for another cause. It's not going to hurt you, which is more than can be said for countless PEDs used in abundance by the same guy swooping in to "save you", lol.

View attachment 338119

I would definitely be open to try it as long as I won’t have issues stopping it

 

[wldb33rz]

As risky ugl lab produced T3 that thousands of members here routinely use you don't comment on?

You're not taking the full labs into account here. The RT3 is the red flag here, not the symptoms of hypothyroidism. Adding exogenous T3 at this point is unlikely to resolve the isue.

Using your favorite diagnostic tool here's the results:

Lab Interpretation and Context​

TSH: 4.78 µIU/mL

• Elevated. Most labs consider 0.45–4.5 as normal, but many functional and some endocrine clinicians use a tighter reference (e.g. 0.5–2.5). This suggests the pituitary is sensing low thyroid activity and trying to stimulate more.

Free T4: 1.2 ng/dL

• Mid-normal. Not alarming, but not suggestive of strong peripheral production.

Free T3: 3.5 pg/mL

• Upper mid-normal (assuming range ~2.3–4.2). This is usually a very good sign unless there’s inefficient utilization or high Reverse T3 (rT3) interfering with action.

Reverse T3: 14 ng/dL

• This is somewhat elevated depending on the lab's upper limit (typically ~10–15). High-normal rT3 in a hypocaloric state, particularly during prolonged weight loss or stress, indicates non-thyroidal illness syndrome (aka low T3 syndrome or adaptive hypothyroidism).

---

Conclusion: Adaptive Downregulation, Not Primary Hypothyroidism​

This looks more like a case of calorie- or stress-induced adaptive thyroid suppression rather than classic hypothyroidism:

• GLP-1s (e.g. semaglutide, liraglutide) reduce appetite, sometimes to the point of borderline malnutrition. They may reduce T3 production or conversion.
• Sustained calorie deficit (especially >6 months) often causes FT3 to drop, rT3 to rise, and TSH to drift up slightly.
• rT3 blocks T3 receptors, so even if FT3 looks good, high rT3 can lead to symptoms.

The TSH elevation is mild and can often resolve with metabolic "relaxation" or refeeding.

---

So, What Should Be Done?​

Option 1: Refeeding/Recovery Phase​

• Try refeeding at maintenance or slightly above (TDEE 2200–2300) for 1–2 weeks.
• Prioritize complex carbs and adequate protein to support liver conversion of T4 → T3.
• Reduce exercise intensity briefly, especially long-duration cardio.
• Monitor symptoms: fatigue, mood, temperature, libido, cycle regularity (if applicable).

If symptoms improve, it’s a strong sign that the thyroid was adapting, not failing.

Option 2: Seek Endocrinology Review​

Consider this if:

• Symptoms persist after refeeding.
• TSH continues to rise above 5.
• FT3 drops or rT3 increases further.
• Signs of autoimmune thyroid disease appear (test for TPO and Tg antibodies).

---

Summary​

• Not true hypothyroidism (yet) — likely adaptive thyroid suppression due to long-term hypocaloric intake and GLP-1 use.
• A strategic refeed for 7–14 days is a low-risk, potentially high-reward approach.
• If no improvement, or labs worsen, then refer to endocrinology to rule out central hypothyroidism or early Hashimoto’s.

Let me know if you want help designing a short-term refeed protocol or interpreting follow-up labs.

 

[BamaCrazy]

Battle of the AI tools. lol.

 

[roguerain00]

How much weight did you lose before starting sema,Tirz,reta ?

I went from 170 to 152ish from Aug last year to mid October. Took a break until late January when I started glp1s. I gained back up to 158 during the break period.

Do a carb load/refeed for a few days to a week. What's happening, based on your labs, is that your thyroid hormone receptors are being downregulated due to sustained lower calorie intake. This is why your T4 and T3 levels are actually quite good, but your TSH is high, although not outrageous but your RT3 is very high. The RT3 acts as an anti-T3 and works to knock it down. This is giving you the hypo symptoms and fatigue. The doc would see your labs and is likely not to refer you to an endo because this isnt a hormone issue, it's a body systems downregulation issue.

I've had to deal with this a few times on the GLP-1 treatments over the last 18 months and just finished a carb load/refeed last week. This will reset your body's demand for thyroid hormones and upregulate to normal function. Be extra careful during the refeed, keep it to around 2100-2200 max, based on your TDEE. You want to be at maintenance so your body isnt stressed and trying to downregulate energy expenditure.

Edit to add: during refeed, keep fats low, and increase carbs. Beans, rice, potatoes, even poptarts work, but generally want to keep your total fat down around 40g or less.

Been eating maintenance or above for the past couple weeks. I do feel like it’s helping so far. I seem to be maintaining at 2400 cals.

Would you advise against eating in a small surplus some days?

 

[wldb33rz]

I went from 170 to 152ish from Aug last year to mid October. Took a break until late January when I started glp1s. I gained back up to 158 during the break period.



Been eating maintenance or above for the past couple weeks. I do feel like it’s helping so far. I seem to be maintaining at 2400 cals.

Would you advise against eating in a small surplus some days?

Depends on what your goals are, a surplus wouldnt be bad per se, but if your goal is weight loss, maintenance is key. So if you're maintaining at 2400 cals, I would keep it there.

 

[readalot]

Battle of the AI tools. lol.

F me, lol.

 

[AlexDavis43]

I would definitely be open to try it as long as I won’t have issues stopping it

My advice is similar to others: get a second opinion (see another general doctor)

High TSH plus your symptoms should warrant a referral to an endo, who you really want monitoring this

Or see if your insurance will cover you going directly to an endo

 

[flasspass123]

Don’t jump on a prescription medication that your Doc hasn’t prescribed. As BigDadd7 mentioned above labs should be taken over time to determine if you really have thyroid issues. One lab out of range is not enough to diagnose anything.

My Wife has hypothyroidism and she had been feeling the same fatigue, plus body pain. At first the Doc was told her she likely has fibromyalgia or lupus. So we threw everything at it that has to do mitochondrial function.

1. NAD+
2. NMN
3. NR
4. Resveratol
5. Glutathione injections
6. Carnitine injections
7. 5-Amino 1MQ
8. Ubiquinol

After 3 days taking the above symptoms that she has been living with for months disappeared. And she has been good ever since.

Also look at your diet to ensure you are getting the calories and nutrients needed. Being in a caloric deficit can cause a lot of those issues also.

This is great to hear. What do you think contributed the most to her improvement in health? I am going through something similar and want to try this out.

 

[BamaCrazy]

This is great to hear. What do you think contributed the most to her improvement in health? I am going through something similar and want to try this out.

Reduction of oxidative stress and repair of mitochondrial function. She has dealt with chronic fatigue, sleep issues and circulatory issues for years. The doctors have misdiagnosed her for years. But now as long as she eats healthy, exercises, and takes those supplements she feels great. Before she lacked the energy to even exercise. Now she’s in the gym 4 days a week and still has plenty of energy to do other things she enjoys.

 

[flasspass123]

Reduction of oxidative stress and repair of mitochondrial function. She has dealt with chronic fatigue, sleep issues and circulatory issues for years. The doctors have misdiagnosed her for years. But now as long as she eats healthy, exercises, and takes those supplements she feels great. Before she lacked the energy to even exercise. Now she’s in the gym 4 days a week and still has plenty of energy to do other things she enjoys.

I sent you a PM

 

[Avies48]

Don’t jump on a prescription medication that your Doc hasn’t prescribed. As BigDadd7 mentioned above labs should be taken over time to determine if you really have thyroid issues. One lab out of range is not enough to diagnose anything.

My Wife has hypothyroidism and she had been feeling the same fatigue, plus body pain. At first the Doc was told her she likely has fibromyalgia or lupus. So we threw everything at it that has to do mitochondrial function.

1. NAD+
2. NMN
3. NR
4. Resveratol
5. Glutathione injections
6. Carnitine injections
7. 5-Amino 1MQ
8. Ubiquinol

After 3 days taking the above symptoms that she has been living with for months disappeared. And she has been good ever since.

Also look at your diet to ensure you are getting the calories and nutrients needed. Being in a caloric deficit can cause a lot of those issues also.

How much of each of these did you do? And what were the dosings like? Around food, inbetween meals etc… i feel drowsy and sleepy and just balahh a lot perhaps some of these could ignite my brain and wakefulness…