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Question about weight loss with phentermine after thyroidectomy

Hello Everyone,
I found this page after my thyroidectomy and I’m so glad I did! A little background, I was diagnosed with Graves’ disease about 3-5 years ago and it went untreated for about 3-4 years due to mostly noncompliance on my side. Well earlier this year I got pregnant with my second child and was diagnosed with hypertension, Chf and mild pulmonary hypertension all of which my cardiologist believes to be related to the high cardiac output from the untreated hyperthyroidism. Long story short I delivered my son at 34 weeks due to end diastolic reverse flow on placenta dopplers. We’re both well. I had a thyroidectomy at 6 weeks postpartum and have been healing fairly well. The chf has since resolved, hypertension and pulmonary hypertension are both predicted to self resolve within the next six months when I am euthyroid. My dilemma is weight loss or lack thereof. As it stands now I am on weight based dosing of levothyroxine. My dosage is 125mcg which is 80% of what my ideal dosage by weight is. My endocrinologist will run tests in 7 weeks to determine my numbers and upon reading all the great advice on here I insisted on a free t3 and t4 test as well.  Well I have been stuck at 185 pounds since the surgery and have not lost any weight although I am barely hungry and go most days with one meal.

I am considering going to a weight loss clinic to get a Rx for Adipex (phentermine). I am eager to know if anyone has gone down this route and it’s success rate. I’ve taken it in the past with great results but this time around I don’t know if it will work. I also haven’t found any contraindications but want to check to be sure.

Any advise will help a great deal.  Thank you all!

Sorry about the long post.
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Avatar universal
Phentermine works by suppressing appetite.  How would that help you when you say you have no appetite and sometimes only eat one meal per day?   I think it would be far better to get your metabolism optimal, by getting your thyroid levels optimal.   As you mentioned, you are taking less T4 med than would be expected for your weight.  In addition,  doctors don't usually understand that hypothyroid patients should be medicated as needed to relieve hypothyroid symptoms, rather than just based on blood tests .  They erroneously think that thyroid med adequate to return TSH within range is adequate.  It is not.   There is much more we need to discuss, but instead of repeating everything here, please click on my name and then scroll down to my Journal and read at least the one page Overview of a paper on Diagnosis and Treatment of Hypothyroidism: A Patient's Perspective.   And then come back for further discussion..  
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Hi Gimel,

Thank you for your response.  I did read your article and the information presented was very eye-opening to say the least. As a medical professional myself, a family nurse practitioner to be exact, we have been taught to titrate Synthroid to the patient’s TSH levels and symptoms, unless there is a history of TSH suppression. So the information about the free T3 levels being indicative of the body’s ability to convert free T4 and a combination of the  three  levels being a better indicator of efficacy was new and definitely worth more exploring which I plan to do in my own journey to health.

The surgeon put me on 100 mcg of Synthroid post thyroidectomy. I had episodes of hypothyroid symptoms shortly after surgery, mainly fatigue, insomnia and constipation, so I went in to see the endocrinologist and we decided on 80% of my ideal body requirement for Synthroid because a piece of my thyroid was left in place (it is expected to eventually die off) due to its proximity to some nerves.  My dosage was increased to 125 µg with the plan to do a set of bloodwork including free T3 and free T4 levels in seven weeks when I’m expected to be a bit more stabilized. Then titrate the medication according to lab results and current symptoms. I sent him a link to your article and I’m curious to hear what his thoughts are on my next visit.

You’re right about phentermine being an appetite suppressant however it is also a stimulant (amphetamine). I am interested in taking it for the stimulant effect in hopes of boosting my metabolism, the appetite suppression won’t hurt either since I don’t think me having no appetite will last for a long time.  I think my body is just yet to recover from having a emergency C-section at 34 weeks and a thyroidectomy all in the span of 6 weeks.  I am just trying to balance the scale by getting ahead and attempting to somewhat “fix” my metabolism while waiting for my thyroid medications to be optimized. I just don’t want to be in a hypothyroid state, put on weight in excess of 30 pounds while I still haven’t lost the baby weight then be put in a position of trying to loose 60 to 100 pounds after my thyroid numbers have been stabilized.
I hope I’m making sense.


Lots to discuss.  First, when did you increase your T4 med to 125?  The reason I ask is that the half-life of T4 is about one week, so it builds up to over 90% of its final effect in 4 weeks.  So, no need to wait 7 weeks for new tests.   To avoid false high results, make sure to defer your daily dose of T4 until after the blood draw.   This is even recommended by the ATA.  

For tests, you should make sure they test for Free T4, Free T3,  TSH  (very little use when taking thyroid med, but  doctors insist), initially Reverse T3, cortisol (a diurnal saliva cortisol panel (free cortisol) is best, but doctors usually will only order morning serum cortisol, which is total cortisol), Vitamin D, B12 and ferritin.  The reason for the additional tests is that hypothyroidism is not just inadequate thyroid hormone.  Instead it is correctly defined as insufficient T3 effect in tissue throughout the body due to inadequate supply of, or response to, thyroid hormone.    There are a number of processes and variables that affect TISSUE T3 EFFECT.  The additional tests represent some of the more important ones.   Note that D should be at least 50 ng/mL, B12 in the upper end of its range and ferritin should be at least 100.

I also suggest that you ask the doctor about switching to a desiccated type thyroid med like Armour Thyroid, or NatureThroid.  There are a number of studies that show patients' Free T3 frequently lags Free T4 levels when taking a T4 medication.    A recent excellent scientific study quantified for the first time the effect of Free T3 level on the incidence of hypothyroid symptoms, and concluded that:  " Hypothyroid symptom relief was associated with both a T4 dose giving TSH-suppression below the lower reference limit and FT3 elevated further into the upper half of its reference range."    If you are successful in changing your med, note in Rec. 9 on page 12 of the paper that one grain of desiccated type thyroid med is not equivalent to 100 mcg of T4, as shown in most conversion tables.  Instead it is only equal to 66 mcg of T4, so your 125 mcg dose of T4 would be  approx. equal to two grains (13o mg) of desiccated type med.  

Since weight is your main concern, note the following formula for estimating Resting Metabolic Rate.

Women: RMR = 655 + (4.35 x weight in pounds) + (4.7 x height in inches) - (4.7 x age in years)

Per this equation, if your RMR dropped 200 calories per day lower than normal,  due to low metabolism due to low TISSUE T3 EFFECT, with no change in diet/exercise, you would slowly gain approx. 46 pounds before the effect of the added weight on your RMR would equalize out the lower metabolism.    I have also seen data that claimed that for RMR, the before and after effect of adequate treatment for hypothyroidism was as much as 450 calories per day.   I have personally experienced this effect.  During a hypo period I gained over 18 pounds in about 8-9 months.  After getting my med dosage increased to get my Free T3 to upper part of its range, I lost the weight without changing anything else.  Doctors don't understand that hypo patients just want to feel normal, and  a TSH within range does not assure normalcy, especially when taking thyroid medication.    

Hi Gimel,
Thank you so much for sharing your research and knowledge with the community. As a clinician and patient it gives me a different perspective to what conventional medicine has taught and I plan to share that knowledge with colleagues and patients alike to improve our patient outcomes.

My synthroid dosage was named on October 17 so I’ll push for labs at the 4 to 5 week mark. Some of the labs, I’ll have my PCP order since Endo is reluctant to.  I’ve only seen my Endo’s PA post surgery but I think I’ll go back to the MD and see if I can push for Armour thyroid. I know that tricare does not cover it unless with pre authorization so I may get some push back there.

I will post my lab results soon as I get them.

Thank you for your response!
Meant synthroid dosage was changed*

Also when you say defer daily dose of Synthroid do you mean defer the dose of synthroid on the day of lab draw? Please clarify. Thank you!
Yes, don't take your morning dose of thyroid med until after the blood draw.  That avoids false high results.  
Ok. Was able to secure appointment for Monday morning. Getting lab work done tomorrow since I took my dose this morning before appointment was confirmed. Will let you know what results are. Thank you for all your help!  
I went in for my appointment and these were my lab results.

Tsh <0.01 range 0.40 -4.50 (I’ve been chronically suppressed from my uncontrolled Graves’ disease prior to thyroidectomy).

Free T4 1.1 range 0.8-1.8
Free T3 2.0 range 2.3 -4.2

My endo totally rejected the idea of free t3 being one of the labs to look at in terms of hypothyroidism treatment

Although reluctant,  I was able to convince him to add cytomel to my meds. I’m to stop cytomel soon as I symptoms of palpitations or elevated heart rate given my history of CHF while pregnant.

So my current medication will be:

1. Continue Synthroid at 125mcg once a day .

2. Add Cytomel 5mcg once a day

I really cannot fathom why the Endo rejected the thought of Free T3 being important.  A person's thyroid status is   determined by the extent of T3 effect in tissue throughout the body.   Doctors usually think that T4 is automatically converted to T3 as needed; however, there are many variables that affect that conversion, including TSH.     There are numerous studies that show when taking T4 med, the Free T3 level lags Free T4, resulting in hypo symptoms.  

Obviously even your Endo was surprised to find your Free T3 below range.   The 5 mcg of T3 added to your med is not going to be nearly enough, but at least it is a start.   Since T3  med reaches full effect on serum levels in a week, there is no need to delay re-testing and an increase in T3 dosage.  

When you go back for followup testing, I suggest that you also get tested for Vitamin D, B12 and ferritin.   D should be at least 50 ng/mL,  B12 in the upper end of its range and ferritin should be at least 100.

Of course your objective is to eliminate your hypo symptoms, which will likely require FT4 around mid-range and FT3 in the upper third of its range.   Along with that vitamin D, B12 and ferritin should be optimal.
The main concern he stated was since t3 has direct cardio effect, he’s cautious about starting me on it given my hx of chf while pregnant, he doesn’t want me to go into symptomatic chf again. Which I can understand but I think when he thought about he decided to up the dosage of cytomel. I just picked it up, he actually sent 50mcg daily not 5 mcg as we had discussed.  I am having my vit d, B12 and ferritin checked on Friday at my PCP’s office. My follow up with the endo is scheduled for 6 weeks or do you think I need to get my thyroid labs done sooner than that? I can do a set at work sooner than that
I just read my post again and realized the pharmacy may have dispensed the wrong dosage because 50mcg is a whole lot of T3 with no T4 med adjustment. So just got off the phone with pharmacy and lo and behold it was the wrong dosage they gave me! I think for now I’ll start 5 mcg daily in 2 doses and recheck my labs in 1 week and go up to 5 mcg twice a day if free t3 still remains low.
Wow, that was very careless of the pharmacy.  

Sounds like a good plan for you.  If you have never been tested for cortisol, you might ask your PCP to do that as well, then you will have covered all the bases. except Reverse T3, just to establish a baseline for it.  But it is best to do a Free T3 from the same  blood draw, so perhaps hold off on the RT3 until next opportunity.

Also, I am very curious about your D, B12 and ferritin levels.  
Johnnie, Tricare will cover Armour Thyroid you can either get it military pharmacy or express scripts online.  Obvious you need the prescription or call in to military pharmacy and I'm sure you can get it at outside pharmacy.
649848 tn?1534633700
I'm not going to say too much because gimel is going to lead you through the thyroid issue so you'll understand it very well.  I just want to say that only eating one meal/day could be making your body conserve fat stores because you might not be eating enough.  It's best to eat small amounts more times/day than a larger amount once/day.  

Also, it's not necessarily the amount you're eating; it could have more to do with "what" you're eating.  I had to stop eating breads, pasta and other items containing white flour and sugar, along with most dairy and add more healthful fats from foods like avocados, olive and coconut oils, etc in order to start losing weight, even after my thyroid hormone levels became normalized.  
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Hello Barb135,
Thank you for your response. I only have been eating once a day since my thyroidectomy on Oct. 12, 2018. I think it’s a cumulative effect of the stress my body has been under in the past six weeks , +34 weeks of a very stressful pregnancy. I expect it to be short-lived but for now I’m letting my body chart its own course to optimal health. I have to admit I don’t eat well when I do eat and I hope to change my eating habits for the better in the very near future. I just feel that I need to allow my body a woosah moment and give it what it wants which seems to be one meal a day at this time. I do make myself  have at least 2 yogurts a day also.

I think I can do well avoiding the white flour containing foods since I don’t tend to gravitate to them. In my case it will be the starches like rice, plantains and potatoes. My biggest fear is gaining an extra 30 pounds while waiting to reset my body’s clock. I am currently overweight at 182 pounds, my ideal body weight is between 120 to 159 pounds with my happy medium at 155. I think those 28 pounds will be difficult to loose as it stands and I’m afraid to go beyond the point of no return by adding on some weight.
1756321 tn?1547095325
I love intermittent fasting. I just had this news article notification show up a few days ago..."Fasting diet 'key to weight-loss', Nobel Prize-winning study shows".  You can google that if you want.
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