a bottle of Synthroid 50 mcg tablets

Q. Can Synthroid and ferrous sulfate be taken at the same time of the day?

A. No. Iron supplements such as ferrous sulfate interfere with the absorption of Synthroid (levothyroxine) taken to treat thyroid problems. Wait at least two hours after Synthroid before taking iron, calcium or other minerals.

Coffee, especially espresso, can also interfere with Synthroid absorption. So if you take your Synthroid in the morning, be sure to wait at least half an hour or preferably an hour before having your coffee.

Another option would be to take the Synthroid at bedtime, at least three hours after supper. Research has shown that this too works very well.

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  1. Mel

    Holy wow. I knew not to take anything with calcium with Synthroid, and to wait two hours after taking it to eat or drink anything else besides water. So, when my doctor prescribed Crestor for high cholesterol, I took it last thing before bed. In trying to be proactive and fight the high cholesterol, I started seriously avoiding anything that contains high amounts of it – as well as anything considered a goitrogen – and my iron level nosedived. Now I have to take an Iron tablet three times daily, and I had no idea I couldn’t take the Synthroid and Iron together. I’ve been doing this all wrong! Thanks for making the information available to everyone on Synthroid.

    It’s crazy. I’m on about a dozen different medications at this point to handle all my symptoms – they’re not that helpful, I still can’t work – and trying to manage them all so that they all work as they should is a daunting task all by itself. It’s good to know that someone out there is knowledgeable about the interactions and is sharing that knowledge so we can be safe, and reap the most benefit from our prescriptions.

  2. j

    If calcium so bad for NDT (or any thy med) why do they add cal in pill? WP Thyroid doesnt list it but IT DOES contain calcium. See Stop The Thyroid Maddness or verify yourself.

  3. Katherine

    I just started Iron and did not know that I was not suppose to take it with my levothyroxine. I took them both at 7 am this morning. I do not know for sure what’s causing this, but I am very nauseated, and feel really rough now. It is 9 am, could this be due to taking them together, or could even the iron itself make me sick like this ?

  4. Katie R

    So, if you are supposed to wait a couple hours after taking synthroid to take calcium or iron, what about my the calcium and iron in my breakfast foods? Is the amount not enough to interfere or should I change what I eat?

    • Treasure

      Everybody’s thyroid symptoms are different, but when I took iron with my Synthoid, it was like I didn’t take the Synthoid at all It counter-acted. My symptoms was no energy, couldn’t hardly walk…felt like I could pass out ( which I have done due to my thyroid) Hope this helps .

  5. D

    Calcium can not be taken with Iron- it binds to it. Many medications bind with iron and calcium respectively. High blood pressure meds … Etc. Sooo… Take Synthroid early am. Take Iron with breakfast and Vitamin C, no dairy in meal. My low iron dosage 325 mgs. Take Calcium with Dairy – small amount an hour after dinner. Stay away from dairy until Iron levels are up- and always keep it away from thyroid meds.
    And for those of you who like to let your Dr. manage the levels- unless he is doing all of the levels every time- that is why you feel bad. Take charge and responsibility for your health.
    Thyroidectomy and a biologist

    • Mikki

      I am just flabbergasted by this. All these med’s I’ve been on and feeling not all good. Weight gain, mood swings, sadness, and everything under the sun. Had tests done to see what the heck has been going on. See that my hormones are at the lowest of low ;(. I have taken these items stated above at the same time in the morning. Not once (having 2 different doctors) was I told to take them at different times of the day. I already had a blood transfusion for low iron, but I have felt like I am regressing. Thank you for this post. Have an appointment in a week and will relate what you have posted and too, change it up on this end to see how I feel taking them at different times of the day.

  6. Cher

    I have taken synthroid for over 30 years. It was only about 10 years ago that a friend informed me that I shouldn’t eat grapefruit at all. My doctor prescribed less medication as a result. It has only been in the last few weeks that the pharmacist has labeled my synthroid with a “do not take with iron and calcium.” I have been drinking coffee with milk, eating breakfast with milk followed by a multivitamin all these years. I rely on my doctor and lab tests to keep my thyroid levels and dosage in sync.

  7. janet

    I couldn’t tolerate iron pills either. But I now take liquid iron (floradix) twice a day and it seems to help…plus it is much easier on the digestive system.
    Peoples Pharmacy response. Take your iron, even liquid iron, at least two hours after the Synthroid.

  8. cw

    I live in the country so we have well water. Our water is very high in iron. Even with the water softener I fight rust stains. Will this iron interfere with my synthroid?

    • Gaylord

      I’m also having an issue with high iron content in my water does it make a difference on synythroid absorption? And I take a blood pressure med for irregular heart beat. I take them an hour apart is that bad?

  9. Mo

    I thought about doing this, too. Since you are taking the iron and calcium at night, do you think you still have the energy you would have if you took them earlier in the day?

  10. BH

    Some pharmacists are brilliant. And some doctors are brilliant. Likewise in either case, the converse can be true. However to claim one profession knows it’s business better than the other knows its stuff, is to wield a pretty broad brush. Also there is a significant difference between the pharmacy profession and the medical one (and I speak as an educated consumer here, and not a member of, nor in any way affiliated with, either profession): The latter involves the training to not only competently recite book knowledge, but also to assume the personal hands-on responsibility of arriving at safe and effective clinical decisions, anew with each individual patient, multiplied many times over in a day. In contrast the former’s role, in the above regard, is that of a formal information support resource.

  11. DS

    Pharmaceutics know more about drugs than doctors from my experience plus doctors have only one class in medical school on nutrition. No one told me for years when to take synthroid or supplements. I think alternative doctors do know more bout this. Be sure and ask if your doctor is up to date on the Endocrinology Academy scale to determine hypothyroidism. It has changed and many doctors have not kept up with that therefore, many people are not properly diagnosed and have many thyroid issues but told they are in the range which is incorrect in many cases if they are not up to date!!! It is also best not to take a generic as the batches are not consistent.

  12. BH

    The advice not to take my thyroid pill (Synthroid) together with my iron supplement is exactly what my pharmacist told me. Yet my doctor doesn’t seem to think it matters a whole lot. So I considered why my doctor would seem to contradict the pharmacist, and a logical explanation easily occurred to me: It’s because my doctor routinely sends me to the lab to have my plasma thyroid hormone levels checked.
    Since the doctor’s choice of Synthroid dosage to have me on is solely determined by what my plasma thyroid hormone levels are, if these levels remain okay, it truly does not matter. And if my iron supplement were for some reason to abruptly begin to interfere with my thyroid, the change in my plasma thyroid hormone level lab values would signal the doctor to adjust my Synthroid dosage accordingly, and that would be all there is to it.
    Yes, it’s good for us health consumers/patients to be aware of certain facts, which doctors often don’t view us as needing to be made aware of. But I can understand where the doctors are coming from, since some (yet by no means all, mind you) of us will often misconstrue a fact due to a less than whole comprehension of the fact’s context.

  13. linda

    I have been taking synthroid for 2 yrs. due to a thyroidectomy but now I also found out I am low in iron, vitamin d and calcium… I take synthroid in morning and I was reading I should take iron at night, but can you take calcium and iron at same time? Thanks for any input!

  14. Mary Ellen

    I am anemic and just started taking Iron again per doctor’s request. I have been taking my Synthroid and iron together. Last night I was so tired that I went to bed at 7:30 p.m. Today I started thinking that maybe the iron was negating the Synthroid – so didn’t take it this morning. After reading everyone’s comments on this website and other websites, I now know for sure to take my iron at night.

  15. Natalie

    I was informed and have done research on this matter, that Snythroid should be taken on a completely empty stomach, and also no food should be consumed approximately 2 hours after you take the pill. I also have anemia, and need to take an iron supplement. I solve this dilemma the following way: First thing in the morning (like with in 5 minutes) I take my synthroid with *water. Then, I get ready etc. I grab breakfast on the way to work and eat once I get there. This usually eats up the 2 hour time slot I need to let the snythroid start to do it’s job.
    *remember not to take your synthroid with OJ or milk etc. as it makes the medicine ineffective.
    In the evening before bed, I take my iron supplement and my daily vitamin.
    I hope this helps everyone. It’s really frustrating when you need two pills that you can’t take at the same time of the day, and both are responsible for giving you energy to make it through the day!!!

  16. Pam

    Because synthroid is absorbed in the lower intestine, I heard you should wait at least four hours before taking synthroid and calcium and/or iron supplements.

  17. Anita F.

    I did not know that I should not take Synthroid with Calcium & Iron.
    I have been taking them with breakfast every day for 4 months now, and as a result, I am convinced that this is why I have been having all these symptoms of feeling dizzy, very cold all the time, numbness in fingers and toes, sore, achy hands and feet.
    Now I know. Do not take Synthroid with Food, wait at least 1\2 hour, then have your meal, and wait 2 hours before taking other supplements.

  18. RichardS

    Same effect w/other irons such as ferrous fumarate? (in my Trader Joe’s Multiple Vitamin & Minerals)

  19. FLM

    My doctor first noticed I had a low white blood count and after several test sent me to a blood specialist. He did after several visits a bone marrow and found I had no iron in my storage system. He gave me a infusion of iron, but this has not brought my count up. I cannot tolerate iron vitamins. I have tried eating food containing iron, but this has not helped. I have started taking a One A Day Vitamin For Women. Any help for this would be very appreciated.

  20. Marge

    I have taken my synthroid for years with iron. I have this listed with all my meds & supplements with the time taken. I give this list whenever I go to the Doctor. Not one has ever informed me that this is bad.
    This an example of why we need to check every aspect of our care & not just rely on the medical profession to keep us informed.
    Thanks for helping to keep us informed.

    • Virginia

      Black Strap Molasses is a source of iron. Your body may absorb it better. I put it in my cereal.

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