Experiences with thyroid meds + wt gain

My endo put me on 25 mcg Synthroid because my TSH was 5.5 andmy thyroid antibodies were 110. I'd been having symptoms like wt gain despite low-carb dieting and exercise, hoarse voice, etc.

I've gone off the Synthroid for a bit. I felt like the Synthroid gave me insulin resistance. I was needing more insulin and when I'd take the Synthroid my blood sugar would go up in the morning. I also gained about 10 pounds.

I've heard two things: 1) that if you undermedicate with T4 (Synthroid) you can gain weight and 2) that some people need both T3 (Cytomel) and T4. Any experiences? How do you recommend I proceed with my endo? He dismisses my concern about my thyroid.

It's so frustrating to eat little, exercise a lot and still have this bloaty, water-weighty feeling.


Hi Maria, I’m going through something very similar right now. My TSH was about 5.5 and I had thyroid antibodies, so I started Synthroid about 3 months ago. 50 mcg didn’t affect me much, but upping the dose to 75 mcg has hit me like a mack truck. I use a CGMS, so I can document a spike in my blood sugar right after I take the pill, and elevated basals thoughout the day. I haven’t figured out anything yet, and my doctor doesn’t seem to think its possible that synthroid has raised my basal insulin so much. If I get any answers I will let you know! Grace

If you have those symptoms, it means your Thyroid issues are not resolved – not that Synthroid itself is causing weight gain, or hoarseness… Thyroid medication has, for many folks, increased insulin needs… and that is something that often needs to be readjusted. On the web, there are counter indications for drugs, and all that stuff. You can perhaps show him some of this, like on this site: http://www.drugs.com/cdi/synthroid.html. “Diabetes patients - Synthroid may affect your blood sugar. Check blood sugar levels closely. Ask your doctor before you change the dose of your diabetes medicine.” It’s possible that he’s mostly a Diabetologist, and that he doesn’t know much about the Thyroid, their meds, tests, etc. Some doctors tend to just go by the book, and not treat the Thyroid wholistically, as it should be… with a Free T4, Free T3, Reverse T3, Antibodies, and metabolic profile. Sometimes even more tests, for parathyroid, andrenal, or the pituitary gland. If he still doesn’t want to believe your symptoms and concerns, do other tests, etc… then as much as a bummer as it is, you may have to visit another doctor who actually specializes more in Thyroid illness. I hope you get it figured out, and I wish ya the best of luck. :slight_smile:

I agree with Lizmari. With your thyroid low, the last thing you want to do if you are anxious about weight gain is discontinue the Synthroid. You want your thyroid levels in target range so you don’t gain weight and it may take some time to get the Synthroid dose stable. When I first was diagnosed with thyroid (I was hyper, but couldn’t control it so had my thyroid destroyed with radiation and now take thyroid replacement) it took quite awhile before we found the right dose so I wasn’t either hyper or hypo. Then I was stable for many years before being diagnosed with diabetes and started insulin. Suddenly my thyroid levels were all out of whack. It took a bit more fiddling for awhile before I got to the stable dose of Synthroid once again and now I regularly test in target range. Just hang inthere and consult an endo that knows enough about the two conditions and how they interact.

My thyroid problem didn’t get solved for several years, so I gained massive amounts of weight, because I wasn’t getting the right dose. They gave me some, but it wasn’t nearly enough. Anyway, I’ve taken the right dose of synthroid for about 4 or 5 years now (after about 5 with nothing or insufficient amounts, during which I kept gaining weight the entire time), and I stopped having a lot of the side effects of hypothyroidism.

I was prescribed cytomel for about 6 months, but I never noticed any difference in how I felt, so I stopped taking it. It might work for you though. I’d recommend taking the thyroid prescription as prescribed. It’s definitely better than nothing. It sometimes takes awhile to have an effect, and also have your doctor retest your TSH levels in a bit and see if you need more.

Our experience is that Synthroid does have an effect on insulin dose (she needs more). If you forget a pill, I find there are lows. Not sure about the weight gain. Hashimotos itself can cause weight gain if not treated. Maybe it’s a dosage thing? You may not be getting enough Synthroid, thereby not effecting the hypothyroidism and it is the hypothyroidism that is still causing the weight gain? I know you have to be very careful about the dose (too much is dangerous). Maybe endos gradually increase until you are getting the right amount.

Update: I’m now on 50 mcg/d except for Sat and Wed when I take 75 mcg. I’ve lost 9 pounds and I’ve lost my poochy stomach.

I still am taking way more insulin than before I started the thyroid meds but I feel better. Here are the symptoms that went away: depression, hoarse voice, hair falling out, overreacting to everything. Interestingly, I used to be a singer but I thought my voice was shot. My voice has come back! Could the thyroid affect the vocal chords?

My TSH is still high though.

And in other news, I have a new baby boy! adopted 5 days ago.

Oh Maria, Congratulations on all of the above ! Enjoy your beautiful baby boy . Thank goodness you are feeling better because you need to in order to keep up with the new addition! Congrats ! Nancy

Hi Maria,

I know this is an old post, but I wanted to tell you that I am facing the same issues. Reading "recovering with t3" helped understanding why I always got a weird insulin resistance, and it is a protocol that advocates going on t3 instead of t4. I will be starting the protocol soon.