Levothyroxine and keto


I’ll try to keep this short but still provide some background: I have Graves Disease so had my thyroid removed in 2013. Since then I’ve been chasing the perfect TSH level and it seems I have to change my Synthroid dosage about every 6 months, sometimes increasing and sometimes decreasing. Unfortunately I experience about 5 weeks of lousy symptoms every time I change doses… not sure why and doc doesn’t believe me but I know it’s true. After four years of experiencing it every time I switch doses, it’s not coincidence.

Anyway, I changed doses again 8 weeks ago and finally started feeling some relief from the symptoms of the change, but yesterday and today they’re back again! I’m totally baffled as to why and then it dawned on me… is the fact that I’ve been doing keto for 2.5 weeks affecting the way my body is metabolizing or absorbing the Synthroid? I was due to have my blood tested this week but now that I feel myself “changing” again, I am going to hold off a few more weeks.

Have we ever figured out if Keto WOE affects our Synthroid/Levothyroxine?

(Melissa Caldwell) #22

Hi Susan, maybe the keto woe is impacting how your thyroid is working and using your supplement. Dr. Eric Berg talks a lot about thyroid on his website and YouTube channel and says there is even a “thyroid” body type which is what I feel like is me. My next thyroid panel is due in January so I may not know how or if keto has changed my numbers. Good Luck with your next lab results and let me know how it went.


I would totally believe that this WOE has an impact on how our thyroid functions, but since I don’t have a thyroid, I have to wonder if it affects how I metabolize my thyroid replacement meds.

Been reading a lot on it but, as with anything, it’s hard to know which source to believe and what info is credible.

(Jeanne Fox) #24

Hi Susan like you I had my thyroid removed after developing Graves 10 years ago and I still suffer with extremely low energy and mood. Like you any information on how keto impacts our hormone replacement would be awesome. I have been doing keto since mid Sept and have lost 19lbs. Which is amazing considering I have been struggling for years to shift it. However I am still tired and would like to arm myself with knowledge so I can keep myself safe and make sure my hormone replacement functions well and is not impacted negatively.

(Roberto) #25

agree… and it’s been my experience-- certainly high bp can be from many things… anyway heres a good article: https://stopthethyroidmadness.com/blood-pressure/

(Marian Diaz) #26

I had my thyroid removed after cancer seven years ago. I added cytomel to my meds after about 8 months of trying to convince my doctor to agree to it. My muscle soreness and inflammation was immediately decreased. I started sleeping better and was able to exercise. I have practiced varying levels of HFLC diets for 14 years and it has been the only way I have been able to lose weight and maintain the loss.

(Karen) #27

Is it an nsaid?

(Marian Diaz) #28

No. Synthroid is T-4, which our bodies convert into T-3 for use. Cytomel is T-3. I take a small dose twice daily. I’m not exactly sure why it helps with the cramping, etc, but people on other thyroid forums have had similar effects.

(Andy Mayeshiba) #29

My wife takes levo and we have been on keto for about 7 weeks.

She has had only modest results (lost maybe 2 lbs) I have lost about 10. Neither of us are particularly big- just wanting to lose some extra fat.

I’m the chef of the family so do all the cooking and make all the food decisions so I’m trying to get the best info I can. She says “ my thyroid does not work at all, that’s why I take the hormone”. If that’s so, then should keto be fine- as if she didn’t have Hashimoto’s, since there’s no thyroid to feed carbs to anyway?

We like the keto diet overall and would like to stick with it but not at the expense of her long term health. So much of the info out there is confusing or contradictory and of course friends or family all think they are doctors too as soon as they read an article or two on the web.

Can anyone demystify this topic for me?

(Karen) #30

Yes lots of confusing info. I’m now off levo, hoping I’ve cleaned my liver enough. I’m testing at the end of the month. I’ll see where I’m at and if Im still hypo.


(Marian Diaz) #31

I’m not sure exactly why from a scientific perspective, but as someone who had thyroid cancer seven years ago and who likely had undiagnosed thyroid issues for years before that, I have only ever been able to lose weight doing the keto diet along with moderate exercise. I usually run a couple of miles or do 25 minutes of intervals, nothing too strenuous, or it ups my cortisol levels even more. With the keto diet alone I lose the initial water weight and I stop gaining weight, but I don’t lose weight without exercise.

(Amy Burchett) #32

That’s good to know, because my BP was high for the first time in my life last time I was at the Dr. My TSH was still high but after losing 65lbs. maybe I do need a lower dose. I’ll talk to my Dr. about that!

(Andrea Barnes) #33

Thank you! I had Graves’ disease too and had a total thyroidectomy and will be on levo for life but am questioning if Keto would even work for me.

(James storie) #34

You’re welcome!

(Bacon by any other name would taste just as great.) #35

According to Dr. Robert Lustig, exercise helps rid us of insulin resistance by encouraging our muscle cells to grow more mitochondria. I suspect that exercise helps you lose weight because more mitochondria burn more fuel, which means your resting metabolic rate is higher.

(Marian Diaz) #36


(Deb) #37

Amy Berger of Tuit Nutrition has a 3 part post on thyroid issues. And I had severe thyroid problems last year that I will post about later that could give insight. Take Thyrogold now…no more T4…no more fasting and all is well.

(Deb) #38

(Deb) #39

My experience last year, if it sheds a little light for anyone in a part of this lifestyle that can affect thyroid:
Even before starting keto, I had a little bit of hypothyroidism, as did my mother, and since the medical community had redefined the scale for TSH levels for when they prescribe T4 meds (to a max of 3.0), and when a pre-race physical showed mine at 4.25 (along with symptoms), my dr. put me on the (useless for me) Synthroid.

Fast forward a couple years to post LCHF and then into keto and IF. I had already lost about 60ish lbs and was hooked on fasting. I pushed myself into all kinds pf fasting protocols, then would calorie restrict coming off the fast so as not to regain.
Not only did I NOT lose weight, but I tanked my thyroid to the tune of a TSH of 8.25, but also destroyed my metabolism. It took me a YEAR to wake the hell up, get my head back on straight, start eating correctly, found the Thyrogold, tested for BG triggers, and now I am healthy, happy and once again can lose effortlessly. Huge lesson learned there!

(Phil Stover) #40

I just started Keto and had Pap Thyroid Cancer about 4 years ago - thanks for posting this because I was wondering if not having a thyroid anymore would cause any issues with Keto. 10 days in and love this new way of life.