Thyroid Disorders Community
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Avatar universal

Synthroid and Metformin

I am 16 years and i was diagnosed with hypothyroid last december. I have gained 35 lbs since then. I play 2 varsity sports (work out 2 1/2 hours a day) and eat decently.  I have not been able to get the weight off.  I take synthroid (100 mg). My doctor put me on metformin yesterday, 500 mg.  I am wondering what i should eat with both that will help with weight loss? and if 500 mg of metformin is enough to lose the weight?  and obviously any insight you can give me.  Thanks!!

This discussion is related to Synthoid and Metformin.
12 Responses
649848 tn?1534637300
The first thing I'd say is that, most likely your thyroid medication is not adjusted properly, for you.

If you have a copy of your latest lab report, it would be a huge help if you could post the tests that were done, along with the results and reference ranges, which vary from lab to lab, so must come from your own report.  

Even if your thyroid hormone levels are "in range", that doesn't mean they are right for you.  A look at your labs will help members assess your situation and allow us to comment more fully.

Have you been diagnosed with diabetes or PCOS?  Or is the metformin strictly for weight loss?  

As for food, stick with the complex carbs, such as that found in veggies and whole grains, lean protein, low/no fat dairy, nuts and seeds, etc.  Make sure to keep portion sizes in check.
1783764 tn?1330814261
Nothing wrong with minimal dairy, and certainly nothing wrong with nuts and seeds, which both happen to be good, healthy, fats.
Avatar universal
thank you!!!! the metformin is strictly for weight loss! and my doctor said we cannot "up" my synthroid becuse my labs say im almost hyper, which is weird because i dont feel hyper at alll!? I feel basically the same, the only symptom that is better is that I am not as sleepy! Does it take awhile for synthroid to kick in? its been almost a year! :( thank you again for answering me! i just really want to lose the weight i have gained! its really effecting my life!
Avatar universal
Please post your thyroid lab test results and reference ranges shown on the lab report.  I am suspicious that your doctor has probably only tested for TSH, or else he has the "Immaculate TSH Belief", by which he thinks TSH is all he needs to be concerned with in diagnosing and treating you.

That is unfortunate because  TSH is a pituitary hormone that is affected by so many variables that it is totally inadequate as a diagnostic for thyroid.  TSH cannot be shown to even correlate adequately with the biologically active thyroid hormones, Free T3 and Free T4, much less with hypo symptoms.  Scientific studies have shown that the thyroid test that correlates best with hypo symptoms is Free T3.  Free T4 and TSH did not correlate at all.  

Many hypo patients taking thyroid meds find that their TSH becomes suppressed.  That does not mean that you are hyper.  You are hyper only if having hyper symptoms due to excessive levels of Free T3 and Free T4.

If you will post those results and ranges, members will be able to provide further advice.
Avatar universal
I am having the same problem - synthroid (75mcg) and recently 1000 mg of Meformin though I am not a diagnosed diabetic.  I went thru menopause at 38 - am now 44.  Gained 40 pounds from October - December 2011 and despite the fact I am a very active person and healthy eater (personal trainer 2x/week, run 10 miles/week, eliptical and bike - exercise EVERY day) I HAVE NOT been able to lose weight - ANY.  I am beyond frustrated.  
Avatar universal
Of course there are a number of potential causes for weight gain, but low metabolism due to low Free T3 is one of the major ones.  Free T3 largely regulates metabolism and many other body functions.  And as mentioned above Free T3 correlated best with hypo symptoms.  Although a spartan diet and extreme exercise will obviously help with weight loss, if your metabolism is low it seems almost impossible to maintain weight loss.  

When Armour thyroid was not available for a while, and I had to switch to other alternatives, I got messed up and became hypothyroid again.  During this period I gained over 25 pounds in about 7-8 months.  I also had numerous other typical hypo symptoms.  As soon as Armour was available again, I switched back and now I take 3 grains of Armour daily.  My Free T3 is 4.0 (range of 2.3 - 4.2) and free t4 is 1.19 (range of .60 - 1.50), and I feel best ever and without any other changes to diet and exercise, I have lost 26 pounds over the last 9 months.  Although I know that it may not be the general case,  it is an example of what low Free T3 and Free T4 can do to you.  One other side benefit I have seen is that my cholesterol level went from a typical 227 down to 167 most recently.

So, if you will please post your thyroid related test results and reference ranges, members can assess the adequacy of your testing and treatment.
Avatar universal
As of May 19, my TSH was 0.459 (range .450-4.5), free T4 was 1.47 (.82-1.77).  I do not see at T3 unless it is the Triiodothyronine Free which was 3.2 (2.0-4.4)
Avatar universal
Your Free T4 is fine.  Yes, the Triiodothyronine Free is the same as Free T3.  

Your Free T3 can stand to be tweaked upward.  The range is far too broad, because of the way it was established, and it has never been corrected.  If it were corrected as done for TSH about 10 years ago, I have estimated that the new range would look more like 3.3 - 4.3.  That is more consistent with ranges based on patients with no evidence of thyroid issues, and thus called "functional" ranges.  Many of our members, myself included, report that symptom relief for them required that  Free T3 was adjusted into the upper third of its range and Free T4 adjusted to around the middle of its range.  The key is to adjust Free T3 as necessary to relieve hypo symptoms.

Another suggestion for now is to test for Reverse T3.  Although not a high probability,  some patients find that their body converts T4 excessively to Reverse T3.  Reverse T3 is a mirror image molecule of T3, but it is biologically inactive, and offsets the effects of Free T3.  The ratio of Free T3 to Reverse T3 has been reported in numerous sources as being a good measure of tissue thyroid levels.

While talking about more testing, if the cause of your hypothyroidism has not been identified, you should test for the thyroid antibodies that indentify the possibility of Hashimoto's Thyroiditis.  Those tests are TPO ab and TG ab.  Also suggest testing for Vitamin A, D, B12 and ferritin.  
Avatar universal
Hello friend, wow ! 1000mg Metformin for non diabetic concerns me.  Are you sure you weren't diagnosed diabetic?  Pre diabetic?  I have never heard diabetic meds prescribed to non diabetics.  I am diabetic 1000mg would gran slam my blood sugars low.  I take 5mg Glip twice a day and still have low blood sugar 2/3 times per week.  My latest A1c lab avg is 72 on meds,.

The trick to losing weight, which worked well for me was low carb diet and no sugar, without exercise I lost 70 lbs,.  I was to fatigued to excercise.  

Lot's of meat/veggies, small portions several times a day.  I believe sugar consumption is why? people gain weight or cannot lose it, just my opinion.  I enjoyed drinking soda, eating ice cream, apple pies, Etc....  Once I eliminated all the sugar, my weight began to drop.  Try the low carb diet with no sugar, and see if it helps.  Best of luck to you, wishing you well :)
Avatar universal
Hello! I tried getting on this so many times and I could not remember my password but finally did!

So I am now 19 years old.  Dr.'s have me on Synthroid (100) and Metformin (2000 mg).  I do not have Diabetes. I do not have periods without Metformin.  Dr.'s tested me for PCOS and I do not have that as well.  

Still can't lose weight at all.  I am 5'5, 165 lbs. I want/should be around 130 lbs.  

My lab results as of March 2014-  T3: 3.2 (range: 2.3-4.2)   T4:1.3 (range: 0.8-1.8)  TSH: .12

Any thoughts/advice??  Thank you so much!
Avatar universal
What other symptoms do you have besides the weight issue?  Have you been tested for Vitamin D, B12 and ferritin?  If so, please post those, with reference ranges.
Avatar universal
It's really just the weight issue and not having periods without Metformin. I have been reading about leptin. It sounds just like me weight issue wise. Do you know anything about that?

Vitamin D, 25-OH: 38        (range: 30-100 ng/mL)
Vitamin D, 25-OH, D3: 38
Vitamin D, 25-OH, D2: <4

I haven't been tested for B12 and ferritin. (what is ferritin)?
Thank you again!!!!!
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649848 tn?1534637300
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