Aa
Aa
A
A
A
Close
Avatar universal

interpreting the rT3 test

I have been on the highest dose of medication for hypothyroidism so far for about 2 weeks: 112 mcg generic T4 and 37 amd 1/2 mcg Cytomel. I feel slightly better, and my previous labs (including a metabolic panel), taken before the latest increase in meds, were the best they've been in 2 years, though the FT3 and FT4 levels and symptoms were still not optimal, thus the slight increase.

As my previous posts have indicated, I am constantly battling with my doctors because of an almost non-existant TSH with symptoms that worsen dramatically if my meds are lowered, especially the Cytomel. I test normally for BOTH Hashimoto's labs, although my sister has that disorder.

My primary doc has finally given me a prescription for FT4, FT3, and rT3 for my next labs, to be taken 5 weeks following this last dosage increase, to determine if a conversion problem could explain my difficulty getting balanced on my meds and why my FT3 has been slow to rise.. After several years of useless testing, I have FINALLY learned that I should not take my medications until after my blood is drawn in order to get an accurate test. My question is, how do I prepare for the rT3 test and how do I calculate the ratio of rT3 to FT3 when the labs come back?

Do I need to stop taking Cytomel for longer than 24 hours before the test ? I normally take it along with T4 when I get up unless I'm having labs, in which case I take both medications when I return from the draw. I ordinarily take the Cytomel all at once and have never experienced any sudden jump in energy or anxiety following taking it, nor any difference when I split the dose. The difference I feel is reflected in less hair loss, less dry skin, and a lessening of other symptoms related to muscle spasms and brain function including depression. I feel an increase in energy overall that I did not have when taking T4 alone.

What is the mathematical formula  for calculating the conversion ration? My primary doc is indulging me in ordering this test, as all 5 endos I've seen have said they "don't believe in it". Of course, these are the same 5 endos who've said, based on my TSH, that I'm not hypothyroid at all, though I had every horrible symptom and a multi-nodular thyroid was discovered after they deigned to give me an ultrasound.

Thank you for your advice, good health to all.
Best Answer
Avatar universal
The formula is FT3 divided by RT3 times 100.  Your answer should be somewhere close to the range of approximately 1.0-2.0.  If, after doing the math, you get someting like 13.3, for example, then you have to adjust that to 1.33 (divide by 10) to compensate for the different units that FT3 and RT3 are expressed in.  OR, just ask!
21 Responses
Sort by: Helpful Oldest Newest
Avatar universal
You sweet thing.....sorry to hear you had a bad experience, I just had to apologize for maybe giving one to somebody, which I really didn't intend. Please don't go off the Forum, it's so valuable, and we all have bad days. I was just on here for a minute (to make the apology!) and saw you had posted. I have to run right now but will get back to you later tonight or tomorrow. Sorry to hear you're having a bad time :- (

Talk to you soon.
Helpful - 0
Avatar universal
I hope you are feeling better?  I have read your posts, this can be so complicated and individual.  

Did you find a good endo in Los Angeles yet??  Mine was chief at Cedars and has gone over seas for a year.  He was great.  I am still in a mess, and found out I am hypo with all the hyper side effects now.  I am juggling my meds and coming down to 75 mc g two days a week, and 88 the rest of the week.

I am one of those people that reflect the hyper  symptoms of tachycardia, diarrhea, and inner jitters and tremors. Most beta blockers knock me out and put my HR to low. I am going crazy with it.  My hair is starting to fall again as well.  Weight the same.  Pure T3 is poison for me.  I get to hyper.  The Cardiologist said all of my irregular heart beats, Diarrhea, and tremors are being caused by the thyroid Med....You know, I already knew that, but just dismissed it because of disbelief.  My bp which has always been normal has shot up along with the other symptoms the last month.  I wake up at 4AM or so with pulse going to 180, BP going up and short of breath.  I have been tested for everything, and it comes with all the different thyroid brands I have tried.  One dose may work for a few months, then I go hyper again.  It is hell!!

One thing I realize is there is no one formula for anyone.  We are all so individual and absorb and process medication differently due to our genetic profile and enzymes we inherit to process the drugs.  What happens to me when I take a pill may be completely different that what you experience.  That is why the CYP 450 test is so valuable.  All I know is that I have Diarrhea within a half hour of taking any Thyroid med.  I have been on three different ones.....

I hope your better and I was not going to ever post on this website again due to my bad experience, however I am back on because of my current situation.  I am looking for a good Endo in Los Angeles.  We both live in close proximity of one another.

Also, had anyone here tried Tirosint and how did they do with it????  Would love some input on it as I don't seem to be able to take anything without severe side effects.  I am taking them anyway, as I have no thyroid and have to...By the way, what is the RT3 test??

And help or comments from anyone would be appreciated...

Take Care
Helpful - 0
Avatar universal
BUMP. Anybody ? I need to order my meds.
Helpful - 0
Avatar universal
NOT TSG test. Typo ! TSH, natch.
Helpful - 0
Avatar universal
Have done some more research on rT3 / T3 ratios, including information on Dr. Holtorf's site. I also read a paper on diodinase enzyme function in thyroid hormone resistance. That paper discusses that serum blood tests are of little use in diagnosing tissue resistance with diodinase disfunction, and that tissue in the pituitary reacts differently than those in the rest of the body, perhaps explaining the inefficacy of the TSG test.  All of my research, including Dr. Holtorf's own statement, suggests that an rT3 ratio of anything less than 2.0 indicates a resistance problem and that raising the T4 supplement further suppresses the ability of T3 to be utilized in the cells. I read some information that says that in a situation like this, Cytomel ONLY is given for a period of up to 12 weeks to clear the rT3 proteins form the body. Is anyone aware of this protocol ? My rT3/ T3 ratio is 1.6.


As you can see in my labs above, my levels of both FreeT4 and FreeT3 have barely risen with a rise in dosage of one or both. And YES, gooolarra, the range for FreeT4 Direct from Quest Labs IS as I said....( .8 - 2.7 ) whereas the Free T4 index range is ( ,8 - 1.8 ) All I know is that the Direct test factors in estrogen binding factors.

As my latest labs show my Free T4 level at less than 1/2 the range and my T3 is ok at 3/4 of the range. But with an rT3 ratio of 1.6, I think that indicates that while I may have adequate serum levels, the rT3 protein is binding some of it, which would explain why I still have some edema and a few other symptoms.

I was intending to raise my T4, which is currently 112 mcg, in light of those labs. But NOW I'm thinking I should LOWER it and RAISE the T3, which is the only hormone I respond to or react to a reduction in medication. My PCP said I could do that if I wanted to, and we'd see what happens to my labs......but it is beyond her comprehension of the condition. I asked if I could also be tested for Leptin resistance, thinking that would also reinforce the idea of tissue resistance, but she refused because she doesn't know what the test is for.

I am currently taking 37 and 1/2 mcg Cytomel, by dividing a 50 mcg tablet. This is NOT a particularly accurate way to dose, as the pill doesn't cut exactly evenly. If I get a separate prescription for lesser mcgs and try to add them together to make doses that aren't standard, I get charged for a whole 'nother prescription, and Cytomel is expensive. My PCP has cleared me to reduce the T4 to 100 mcg (better for me w/out the red dye anyway) and up the Cytomel to 50 mcg. That's a HUGE jump in the T3, and in the total hormone count. I will be bumping the T3 by 12 and 1/2 mcg = 50 mcg hormone> My total hormone consumption will be 300 mcg, up from 262 mcg. Doesn't that seem like a huge jump ?

It has taken me so long to get to where I am now. My hair is just growing back from the LAST time the endo lowered my T3, and I've just lost 8 lbs. of the 15 I gained when he did that. I could lower the T4 to 75 mcg while raising the T3 to 50....that would put me at 275, not such a big jump. But what if I'm wrong about the rT3 ? The last endo I went to said he didn't BELIEVE in the rT3 test and the other 4 endos refused to discuss anything but TSH.

ANY suggestions or comments will be appreciated. The edema is very uncomfortable, still having some spastic feet and muscle soreness and super-dry skin. I will run out of meds in 4 days.

Thanks a lot.

Helpful - 0
Avatar universal
Hahahahaaaaaa, yep, pinning one's hopes on Medicare gets more dicey every day and turns out ain't so hot to begin with. Doctors hate it because it doesn't compensate them fairly, so IF you can get an appointment, they're grumpy about it. My longtime primary care doc, faced w/ now treating me under Medicare, just flat out told me I was having trouble finding new doctors because of my insurance. Of course, everybody with a conscience hates Wellpoint / Blue Cross. Their record speaks for itself and I was appalled to have to choose them, purely for access to Cytomel and to their contract with Express Scripts, which has a compounding pharmacy for the BHRT I take.

Unfortunately Cytomel only comes in 5, 25, and 50 mcg dosages. My next task is to explore whether a compounded medication would be cheaper under the circumstances and whether a compounding pharmacist would be more consistent with the exact amount of the active ingredient, unlike generic drug providers with their 10% >< variation allowed by the FDA. I don't understand that one at all.
Helpful - 0
Avatar universal
I'm not all that familiar with Cytomel tablet doses, but could you buy 75 mcg tablets (don't know if 75s exist) and split them.  Then, you'd only need 15 pills for the month.  Actually, this works great for a lot of things.  There's usually only an incremental price increase for the higher dose, so you really make out.

So, you're telling me that I shouldn't pin all my hopes on Medicare???!!!  It seems every time I turn around lately, someone is managing to get more, not less, money out of me.  We won't shoot you just yet...
Helpful - 0
Avatar universal
Thank you so much ! I haven't heard of THR. It certainly seems like there's some kind of inability for my body to be nourished. I will research.

I'm having such a problem with my insurance since I went on Medicare.In my previous insurance, it didn't matter how many pills I took a month, that was my monthly dose and was covered under my co-pay. Now, with my Blue Cross PPO, it's a problem, first because they categorize Cytomel at the highest tier and I apparently can't take the generic, then they charge per pill over 30 pills. I paid $53 for the 50 mcg Cytomel last month, splitting 1 pill in half, and then the half into 1/4 to make 37 and 1/2 mcg. what a pain. But it would have been even more expensive to get 25 mcg. pills with less splitting. The total price at the drugstore is $74 , so my insurance is only covering $20 of the medication. I thought once I went on Medicare I would get some relief from high insurance bils, but it has been just the opposite, a $25 co-pay every time I turn around, and drugs WAY more expensive. Blue Cross was the ONLY coverage that even had Cytomel on their formulary at all. Lost in America. Shoot me now.
Helpful - 0
Avatar universal
Only 17 years?!  I thought a lot of them had missed everything since the development of synthetics in the '60s!  LOL  Maybe we could call it midwitchery...

I'm fairly sure you do have a conversion problem.  With your high dose of T3, I don't think you could tolerate it if you didn't.  However, slow conversion does not necessarily imply RT3 dominance.  They're two separate issues.

"Endemic craziness"?  OMG, please tell me someone didn't actually say that.

I'm so glad you were able to put together such a good personal history...that is probably THE most important thing we can do as patients.  We always engourage people to get all lab results for their own records and to jot down meds and symptoms prior to each.  

If the 112 mcg tablet contains red dye, you might try combining a 100 mcg and half a 25 mcg tablet to get the 112 without the red dye.

Well, don't know about wisdom, but since you did just up your meds a bit again, I still think there's the possibility that this could go away with a little time.  Some of our more stubborn symptoms can take a while to go away, especially if they've been with us for some time.  Also, most of us find that labs improve and symptoms may lag that improvement.  I'm hoping so, anyway!

Yes, I would consider the amount you are taking at the moment high...only because most people reach a therapeutic dose at 200 mcg or less (combined), IF (the big fat IF) there are no issues (metabolic) besides thyroid going on.  Have you done any research on THR (thyroid hormone resistance)?  In THR, FT3 levels have to be extremely high for cells to get an adequate amount.  Often, FT3 levels have to be MUCH higher than yours, however, before they feel well...often several TIMES the upper limit of the range.  Just something you might explore to see if any lightbulbs come on...    
Helpful - 0
Avatar universal
bump
Helpful - 0
Avatar universal
Oh, I forgot....No I didn't ever think the dosage recommendation on the Cytomel site (FOR MYXEDEMA ONLY) was to be taken *in addition to * T4, that's why I was trying to make sure my combined medication, mutiplied out, still came within their range and in fact what I'm taking puts me at the lower end of their recommendation. And they DO recommend titrating up incrementally according to symptoms, which I was glad to see since the idiotic endos don't seem to grasp the concept !

It seems like the total amount I'm taking now would be considered "high" in your estimation, and I'm just wondering why I seem to need that, since my TSH was always "within low normal range" before I was treated, thus causing this struggle in the first place. One endo had the nerve to say "Well, EVERYBODY feels better when they're on speed." and wanted me to go off meds cold turkey immediately ! Really ? Even someone who was having non-stop panic attacks and a verified anxiety disorder....that got better with thyroid meds ? Thank god for my primary, who thought that was appalling.

I should alos mention that I've had "paradoxical" drug reactions in the past, that my sister has Hashimoto's, and that there are other auto-immune manifestations within my family.

Thanks again for your patience and expertise !
Helpful - 0
Avatar universal
Golarra, flyingfool....

LOL y'all ! but not really funny, right ? My best information has research doctors and the more advanced practitioners complaining that current standard endocrinology practice is 17 years behind the most recent knowledge. They bemoan the fact that new endocrinologists are trained by medical professors who either do not follow or have no time to read the updated medical information contained in JAMA and The European Journal of Medicine, or to follow results of clinical trials. Whattayagunnado ??? Too bad there's no "mid-wife" equivalency for the practice of endocrinology, right goolarra ? We could set up an office. SCARY.

I'm just trying to figure out if I have a conversion problem in retrospect, wondering why straight T4 therapy did absolutely nothing for me, yet 3 days after the addition of T3 I was at least mentally and energetically well, and had rapid physical results starting within 3 weeks. My primary, not knowing any better, gave me 25 mcg straight out the gate in addition to the 75 mcg generic T4 I was already taking. Luckily it wasn't too strong ! I had a lot of work to do with acupuncture and therapy to rebuild my extremely fragile state, but the meds worked right away and my therapist came to the conclusion that my previous severe depression and anxiety attacks were from a thyroid problem and nothing else. As I saw her once a week, she saw the rapid weight loss and the regrowth of my hair, all of which I had been told (by an endo) were due to aging and endemic craziness. I've lost 10 of what should have been the best, most productive years of my life due to bad medical care.

I do still have swelling and pain in my extremities and the overall "cottage cheese" look on my whole body that is apparently typical of mucin deposits. I couldn't understand what had happened to me, as I've eaten conscientiously and naturally lightly my whole life, had 5% body fat my whole life without ever dieting or watching what I ate.....suddenly blew up like a balloon following several hit-from-the-rear whiplash accidents and a severe exposure to pesticides and environmental toxins....along with loss of body and head hair, disrupted metabolic panels, painfully dry skin, dramatic bleeding with my period, and a voice that sounded like I had laryngitis. Just normal aging, right ?

Because the endos jiggered with my meds so much, it may be that the myxedema (if that's what it is) isn't going to go away this time. I've read research that suggests that could happen, but I'm hoping for the best. It did, completely, within a couple of months of me going on meds the first time at 100 mcg T4 and 25 mcg Cytomel. Four months after the Cytomel was replaced with the generic, I developed hyper symptoms and my primary doc agreed that I should cut my T3 in half....neither of us knew how strong it was and that was a big mistake. I almost immediately became clinically depressed, couldn't focus my eyes or think straight, and gained 15 lbs. in 3 weeks......all the horrible symptoms came back, and so she sent me to endos, I've been fighting my way back ever since, and it was only when i sat down, made a chart of the results of every blood test I ever had, plugged in my dosages from my pharmacy records, figured out that the problems started back with the introduction of generic T3....that I became "armed and dangerous", with information, that is !

The red dye is contained in all 112 mcg doses of T4, no matter the manufacturer. I've been breaking out in little itchy blisters even though I'm supposedly not allergic to anything. But I had a coughing reaction to red dye before. I'm hoping after I have the next labs, that I may be able to drop the T4 back to 100 mcg and either leave the Cytomel where it is or raise it to 50mcg, and drop the T4 to 75mcg since my body really seems to only react positively to T3, yet I don't want to only take that. My primary is really pissed off at me for jiggering with the meds like this, it scares her to be prescribing for "something so esoteric", but the endos I've called only want to deal with diabetes or say they deal with postpartum hypothyroidism , or don't seem to understand when I ask about T4/T3 therapy. I'm terrified to go to another one and have him insist on jiggering my meds again, and I'm also tired of spending money on nothing. So I hope my next labs are where I want them to be, and that my primary, based on the EXTREMELY good metabolic panel I had last time, (cholesterol dropped from 220 back to it's usual 167, yaay me !) will continue to indulge me.

Any words of wisdom or insights still appreciated from your Endocrinology 101, goolarra ! I'm concerned about the swelling and it hurts. And STILL looking for a progressive endocrinologist who takes my insurance in LOS ANGELES. Wish I could afford to go to the wholistic doctor in Torrance who did the live chat :- (  Is that ever going to be posted ?


I thank you for your time, hope this post gives insight to others as well. Wishing good health to all !
Helpful - 0
Avatar universal
I know it can be very redundant for you, the typist, but I think for most of us it's so much easier to have as much information as possible right here in the current thread.  I scroll up and refer to stuff all the time, and it's much easier for me than flipping back and forth from here to personal pages.  Anything you suspect you'll use several times (like labs) can be typed into your word processor for future cutting and pasting.

I did have to laugh...let me introduce myself, I'm endocrinology 101.  Anything you want to know about thyroid?  LOL  I think I might have been tempted to feed my baggie of hair to my endo...right there, baggie and all!  He doesn't know about hair?  Where's he been?

Your labs look really good.  FT4 is right at midrange, and FT3 is in the top third (74%).  I think it's highly unlikely that you have RT3 dominance because your FT3 is so high.  It's still worth testing, of course.

If you've had a problem with dyes before, it might be worthwhile to try a different brand of meds, or you might just try a different strength (might have to split/and or combine) as dyes vary according to dosage.    Do you think it's the T4 or T3 meds that have the red dye?  

You do understand correctly...just don't take your T3 meds on the morning of the draw.  Sorry to be confusing...FT3 divided by RT3 times 100.  The star is often used interchangeably with an "x" as a multiplication sign.

Let me first say that there is really no "maximum" dose of either T4 or T3 meds.  Many experts feel that dose should be increased until all symptoms are relieved.  However, in the absence of some esoteric thyroid conditions (e.g. resistance syndromes), there is what I'd call a "usual maximum" (i.e. the dose at which most people are under, or where we start to think something else might be going on).  

That being said, I'm really quite surprised that the Cytomel site says the usual maintenance dose is 50-100 mcg (for MYXEDEMA only).  I’d just like to note for the thread that they say the usual maintenance dose for Cytomel (taken without T4 meds) is 25-75 mcg. Your math and all your logic is correct...that would translate into 200-400 mcg of T4 meds.  In my experience, anything over 200 mcg of T4 is a HIGH dose, not the lower end of "maintenance".  So, I suspect that the 50-100 mcg applies ONLY if you take T3 without any T4 and only for myxedema.  I also don't know what is considered a "maintenance" dose for T3-only because it's so very seldom used on a long-term basis by itself.  It's used (by itself) to treat RT3 dominance on a very temporary basis, and it's used exclusively for longer periods of time to treat some resistance syndromes (very rare).  So, I'm not exactly sure what population the 50-100 mcg is being applied to, and I'm not sure what "maintenance" means as far as T3 meds are concerned because few people are on T3-only for long enough to reach a "maintenance" level.  Hope I haven't been too confusing here...  Bottom line: I wouldn't apply the 50-100 mcg usual maintenance dose when taking a combo of T3 and T4.

You say you feel better than you have in 10 years.  Do you still have some swelling in your legs/feet, or did I misinterpret that?  Some symptoms take a while to go away once we’ve reached our personal optimum dose.  Do you note any improvement indicating that it just might be a matter of time?  Everything seems to be looking good.  Unless the swelling continues to be a problem, it seems that you've found what works for you, and your biggest problem is going to be not allowing some jerk to change your meds on you for no good reason!  
Helpful - 0
Avatar universal
Do medical schools even teach Dr's about symptoms for any disease anymore?

The reason why I ask is that Dr's today seem to ONLY go by a lab test number and some arbitrary range.  If you fit within that they want to no longer be bothered with you!

This is crazy!  Most probably the result of the lawsuit happy world we live in.  With Dr's totally paranoid to ever prescribe a thing outside the "normal" range. So they won't get sued if they make an error.  For them they could care less if you feel completely well.  They will get you to a point that THEY won't get sued and then go NO FURTHER.  To a certain extent I can understand their fear.  After all their whole career can be destroyed by a single lawsuit judgement against them.  It is hard to defend yourself to the medical board I would think when you are prescribing medicine outside of traditional amounts with lab tests that are not completely in line with the average knowledge of Dr's.

On the other hand, why did they become Dr's if they don't want to help people get well?
Helpful - 0
Avatar universal
Please excuse me, In regard to the manufaturer's suggested maintenance dose of Cytomel for myxedema, that would translate to 200 - 400 mcg of total hormone replacement, if I'm not mistaken. Therefore my total dose of 262 mcg would not be not excessive for that criteria if I understand correctly.
Helpful - 0
Avatar universal
Dear goolarra,

Hi, just got the notice that you'd replied.would have gotten back sooner. Should I start entering my lab results on my page so people can refer to them there? I'm not sure how the site works exactly, but I've entered my labs so many times in response to others that it seems it might be more productive to refer to my page. Is that something that others do ?

i'm aware that my TSH will be non-existent when I'm taking T3....it was around 1.4 BEFORE  I went on meds, which is why the endo ignored my copious symptoms. Of course it will now be low ! She also never tested Frees, or T3 at all, only Total T4, which as I recall was also around 1.something. So according to her, I was normal and just possibly a psych patient.....until they finally found the nodules and put me on T4, "not because I had a thyroid problem, but just to inhibit the growth of the nodules."  (they shrank) Anyway, try telling ANY endo (seen 5) that it doesn't matter about my TSH. Or that I didn't get better until I insisted on adding Cytomel. Lucky for me my primary doc sees the symptoms and tries to work with me, although she's frustrated and frightened to be prescribing beyond her medical knowledge. I kept telling her I had myxedema (obvious) but she insisted it was impossible because she only associated it with coma.......until I took her the research from JAMA etc., which she doesn't have time to read. Grrrrrrrrrrrr. Even the Cytomel website says those with myxedemic deposits need to take extra medication. I can gain and lose 15 lbs. in a matter of weeks when they mess with the T3 dosage, and the swelling in my extremities is non-pitting and painful. I also have the rash, which confuses the hell out of dermatologists yet is pictured under the disorder. My sodium and potassium levels are fine, I usually do all my own cooking with little salt, an had a BAD reaction to Inderal because I don't need it.. I'm tired of going to endocrinology school in my body.

The last endo insisted on lowering my meds because I'm "NOT hypothyroid" and my FREEs, though low, were "in the normal range". My primary said I should do it just to show him what happens, aargh. My hair started falling out in handfuls immediately, I gained 15 lbs.in 3 weeks, my blood pressure went up, I became dyslexic when typing etc.etc. etc. The endo, when presented with a ziploc bag 1/2 full of golf ball-sized clumps and 1/8 inch strands of hair that fell out in one week, said he didn't know anything about hair, maybe I should go to a dermatologist. (been, many times, useless) So my primary raised my meds again and I slowly began to recover. I also had a bad reaction to generic T3, so now back on expensive Cytomel.

Labs, May 23, 2011 / Quest
medication 100 mcg generic T4 (Mylan)  25 mcg Cytomel

TSH                          below .01        ( .40 - 4.5 )
FREE T4 , direct                 1.1         ( .8 - 2.7 )
FREE T3                            3.1         ( 2.3 - 4.2 )

Labs,July 12, 2011 / Quest
medication 112 mcg generic T4 (Mylan)  31 and 1/2 mcg Cytomel

TSH                          below .01         ( .40 - 4.5 )
FREE T4                            1.3         ( .8 - 1.8 )
(NOT direct, doctor error, I take BHRT )
FREE T3                            3.7          ( 2.3 - 4.2 )  

At that point, the hair loss and most of the spastic feet stopped and the swelling slightly reduced but was still painful, although I still had the "Oprah bumps" on my cheeks and was still typing dyslexically (now mostly stopped) and fatigued. I dramatically stopped craving sugar.

SO, for the past two weeks I've been on 112 mcg T4 but having a lot of mucus and wondering if it's from red dye, which I've had a problem with before, and am on 37 and 1/2 mcg Cytomel. I have lost about 8 lbs. without changing anything other than meds, though I am still 20 lbs above the weight I dropped to when I was first put on combination T4/T3 two years ago before the various endos started messing with my metabolism, and 30 lbs above my normal lifetime weight. The swelling is less but not gone (love the crinkly hanging skin) I only have to put cream on twice a day instead of 8 times, my mouth has stopped cracking , and hair is starting to grow back and is naturally curly once more.

Of course I have been told by 5 endos that there is no such thing as a conversion problem or that I couldn't possibly have it or that the rT3 test is useless. My primary has ordered it on my request, and we are no longer going to bother testing my TSH.

So if I understand you correctly....don't take the meds before the test, but not necessary to stop more than 24 hours before. Divide the FREE T3 by the rT3. But I don't undersatnd what "rT3 *100" means. Could you explain ?

Just for reference, the Cytomel manufacturer's website states, regarding myxedema:
"Recommended starting dose is 5mcg daily. This may be increased by 5-10 mcg daily every 2-3 weeks. When 25 mcg daily is reached, dosage may be increased by 5-25 mcg every 2 weeks until a satisfactory therapeutic response is reached. USUAL MAINTENANCE DOSE IS 50-100 mcg DAILY."

Since T3 is 4X stronger than T4 and I am on both, my current total thyroid hormone supplementation is 262 mcg a day. I feel better than I have in at least 10 years, and am extremely grateful not to be having ANY panic attacks or depression since being on the higher dosage. My bone density is slightly better in some areas, my WBC is now normal, my cholesterol and triglyceride levels are now back to their historic lows, and my eGFR levels have also normalized. The nodules on my thyroid have remained reduced. I DO still have rashes that are identified with thyroid problems pictured on medical websites. The ONLY thing that is ANY different in my life, the ONLY change including diet and exercise, is that I am on the stronger combination thyroid meds.

Any thoughts on all of this, as well as additional clarification on the rT3 ratio in terms of what the * means would be most welcome. I think I understand about the 100 multiplier and the difference in ranges. THANK YOU, goolarra !


                      



Helpful - 0
Avatar universal
Hi, I just responded to you on another thread.  Yes, the formula...thank you so much for the information.  This is a wonderful site...many good people that are in need and there is a lot of good information.  We are all a family in this process here....
I also told you in the other post that I had RAI and have no thyroid.  I think you were under the impression that I had one...

:-))
Helpful - 0
Avatar universal
Which one?  The formula?
Helpful - 0
Avatar universal
Gosh, I cannot absorb that one.  Is there an easier explanation???
Helpful - 0
Avatar universal
I'd like to see your actual latest thyroid test results, with ranges, please!

Many factors influence TSH level besides FT3 and FT4 levels.  One of those things is T3 meds.  Many of us find that T3 meds suppress TSH levels making TSH a useless test for us.  

You're right...you shouldn't take your Cytomel before the blood draw (24 hours is enough), and no further preparation is needed for the RT3 test.

The formula for figuring the ratio of FT3 to RT3 is:FT3 / RT3 * 100, and the reference range for the ratio is approximately 1.0-2.0 with the higher end of the range being preferable.  The "100" is a fudge factor because FT3 and RT3 are often expressed in different units, depending on the lab.  If your result isn't somewhere in the vicinity of 1.0-2.0, you might have to adjust by a factor of 10.  For example, if you get 20.0 when you divide FT3 by RT3, the ratio is really 2.0.  There are all kinds of variations on the range due to that (i.e. it will sometimes be expressed as something like 10.0-20.0).  
Helpful - 0
Have an Answer?

You are reading content posted in the Thyroid Disorders Community

Top Thyroid Answerers
649848 tn?1534633700
FL
Avatar universal
MI
1756321 tn?1547095325
Queensland, Australia
Learn About Top Answerers
Didn't find the answer you were looking for?
Ask a question
Popular Resources
We tapped the CDC for information on what you need to know about radiation exposure
Endocrinologist Mark Lupo, MD, answers 10 questions about thyroid disorders and how to treat them
A list of national and international resources and hotlines to help connect you to needed health and medical services.
Herpes sores blister, then burst, scab and heal.
Herpes spreads by oral, vaginal and anal sex.
STIs are the most common cause of genital sores.