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T4 to T3 conversion
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T4 to T3 conversion

I had an RAI ablation after being diagnosed with Grave's disease 10 years ago and have been on levothyroxine since.  Does synthetic T4 convert to T3?  I thought that T4 to T3 conversions occurred in the thyroid gland...so without one, where does this conversion take place?

Desperately need advice as I've been miserable when my TSH is in the "normal range" and have resorted to self-treatment.
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Although both T3 and T4 are produced in a healthy thyroid, far more T4 is produced than T3.  T4 is converted to T3 primarily in the liver, but the kidneys are also involved to a lesser extent as are other organs.  Yes, synthetic T4 does convert to T3, unless you are a "slow converter".  

Please post your free T3, free T4 (and their reference ranges) and TSH.  It sounds like you are either undermedicated or might require a bit of T3 meds if your FT3 and FT4 look out of balance.  It's difficult to comment further without seeing those.
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393685_tn?1325870933
I have about the same background as you with this disease. Grave's - then RAI

Goolaara is right on the mechanics of conversion.

I found it wasn't the right conversion for me as many do .

Until I found out my correct ratios of FT3 and FT4 I needed - I was lost - and sick too.

Get the labs.
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649848_tn?1357751184
It's usually not a good idea to self-medicate........what are you self medicating with? What are your most recent labs and were they done before or after you began self treating.

Please post your labs if you have them, along with dosage info.

I'm on both a T4 (levo) and T3 med because I wasn't converting enough T4 to T3.  Currently, doing well.
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10419551_tn?1410006149
Anyone ever explore if the could enhance T3 conversion? perhaps through diet and/or gut healing?
Why the attitude that once on HRT on it for life?
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Correcting a selenium deficiency can enhance conversion since the enzyme that catalyzes the conversion of T4 to T3 is selenium based.  Some conversion happens in the liver and kidneys, but a lot of it also happens right at the cell that needs it.  

By HRT do you mean thyroid hormone replacement?  The original poster had a thyroid ablation, so she has no choice but to be on replacement for life.  By far, most thyroid disease is autoimmune, Graves' or Hashi's.  Neither of those is a curable disease.  In the case of Hashi's, it's also progressive, i.e. antibodies keep destroying the thyroid until it's "dead".  
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649848_tn?1357751184
What she said.  As is the case with many of us, myself included, Hashi has done so much damage that our thyroid no longer produces any hormones at all and we are dependent on the hormones we get through our daily med.  

Studies have shown that supplementing with selenium can help with the conversion of T4 to T3, but for some of us (again including myself), even that's not enough; we still have add a source of added T3.
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10419551_tn?1410006149
Well 5 tears ago I was diagnosed with hypothyroid, given synthroid and white coat declared me "fixed based only on TSH. Well symptoms continued, switched to armour, symptoms abated for the most part. Also was placed on Testosterone therapy, Went Gluten free 5 years ago dropped weight and did a couple of ironmans. Last winter I started having super high body heat I felt in metabolic hyper drive and I was. Quit all supplements felt allot better then 2 months after cessation I did have chronic afternoon negative energy. 2 months after stoppage blood tests revealed T4 low normal and T3 in the tank, Testosterone was in the tank. Month ago started using a sleep enhancement device- earth pulse, it has helped sleep so hopefully I get another round of tests to see effect of earthpulse, next is to add my mineral supplementation, BTW I work 12 hour shifts 7 on 7 off days and nights. I also has apnea diagnosed originally and use a dental device to keep airway from being obstructed.
Dose my plan seem reasonable, after the mineral I wll look at adding back T.
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649848_tn?1357751184
As far as I'm concerned, any doctor who would pronounce a patient "fixed" on the basis of TSH, doesn't deserve to be called a doctor.  I guess no one realized that it was the medication that was keeping your TSH in the normal range in the first place?

I'm guessing by "metabolic hyper drive" you were over medicated?  Is that correct?  It seems that it would have made more sense to simply decrease your Armour dosage than to stop all med and I'm not surprised that it only took 2 months for T4 and T3 to tank.  

By the way, were those Free T4 and Free T3 or were they Total T4 and Total T3?  They aren't the same tests, so when you're having blood work, always make sure you're specifying Free T3 and Free T4.  If you just say T4 and T3, you get the Totals by default and those are considered obsolete and of little value.

As goolarra noted above, most thyroid disease is autoimmune, caused by, either, Graves or Hashimoto's and Hashimoto's is progressive in that it continues to attack your thyroid until it is, completely, non-functional. The fact that it only took 2 months for your T4 and T3 to tank after stopping the medication would indicate this could be the case.

While there are some vitamins/minerals that are necessary for the proper metabolism of thyroid hormones, you can't live indefinitely without the hormones themselves, and once your thyroid stops working, nothing can make it start working again.  Your thyroid controls your heart rate, body temperature, metabolism and other body functions.  If you wait too long to add back the thyroid hormones, you run the risk of a life threatening condition called myxedema coma that requires hospitalization.

You don't say whether you've been tested for Hashimoto's or not, so that would be the first thing you need to find out.  If you have Hashimoto's and it has destroyed your thyroid to the point where it can't produce enough hormones, which seems to be the case, then no, your plan does "not" sound reasonable.
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