Withdrawal symptoms of Ferrous Sulfate

Hi Everyone, I was taking Ferrous Sulfate 325 mg 10 days ago for iron deficiency anemia. I took 1 tablet each for 2 days and then 2 tablets each of the next 3 days. From the 2nd day on wards I was having a lot of difficulty breathing, which I didn't realise then. Took a total of 8 tablets over 5 days and today is exactly 7 days I have stopped taking them when I realised it was severe allergic reaction to this tablet that I was having, but I am still having difficulty breathing sometime (say about 25% of what it initially was) and last night started having acid reflux after dinner. I am 50 and have never ever had acid reflux. Has anyone experienced any withdrawal symptoms from taking Ferrous Sulfate. If yes, how long does it last and how to get over it. I have to start another iron supplement (will try ferrous gluconate) but not until the allergic reaction and withdrawal symptoms of ferrous sulphate are completely gone, because I did try 1 ferrous gloconate after stoping ferrous sulfate for 3 days and that created more difficulty breathing, so want.

I would greatly appreciate your comments and response.



18 Replies

  • Hi,

    What are your current ferritin, B12 and folate levels ?

    Shortness of breath and acid reflux can be associated with B12 deficiency.


  • Hi, Thank you for responding. My Ferritin end of July was 9 (did the test while I was away), but it wasn't until end of August that I submitted the report to my dr. and she told me to take iron supplements.

    I told my Dr. to test my B12 (she didn't tell me) and it was 292 early September. Since then I have taken 2 B12 shots and will take a third one today. Took a B12 sublingual tablet for a couple weeks, but after the reaction from Ferrous sulphate stopped that. Bought Sundown liquid (which agreed with me 2 years ago), but even half dropper of that is now causing some difficulty breathing. And this difficulty breathing was never present before I took Ferrous Sulphate. I asked my Dr. if I need to check my Folate and she said no. I am going to see another internist tomorrow.

  • Your reaction is unusually strong. Have you discussed this with your doctor and considered the possibility of iron infusion instead? Then you could retry iron at a much much lower dose - a trickle feed, and see how you get on.

    This is an excerpt from the US National Health site on iron - the US is much better than the NHS on info I think. Most people don't react as you have done but this is why I think it is always best to start fairly low with iron supps to test individual reactions.

    "Health Risks from Excessive Iron

    Adults with normal intestinal function have very little risk of iron overload from dietary sources of iron [2]. However, acute intakes of more than 20 mg/kg iron from supplements or medicines can lead to gastric upset, constipation, nausea, abdominal pain, vomiting, and faintness, especially if food is not taken at the same time [2,5]. Taking supplements containing 25 mg elemental iron or more can also reduce zinc absorption and plasma zinc concentrations [3,70,71]. In severe cases (e.g., one-time ingestions of 60 mg/kg), overdoses of iron can lead to multisystem organ failure, coma, convulsions, and even death [18,72]."

    (Please don't get too worried about the last one... )

    I will put the link to the full page on another message in case this one wipes while I copy it.

    From memory it says that up to 40mg should be fine, but I think you need to try to check out why you are reacting so strongly. On a similar dose of sulphate I felt light-headed, detached, and sick and I would never take it again, or any iron in such quantity. But breathing problems ... that is serious.

  • ods.od.nih.gov/factsheets/I...

    There is an implication above that you might not have normal gut function.... is that the case, do you know? Do you know the reason for your anaemia?

  • OK, I've looked around the net, I think you should go straight back to your GP reporting this symptom and not try any other iron preparation at all in whatever dose until you have done this. You need very, very expert advice.

    If you are allergic to iron, an iron infusion could be dangerous too. You maybe need a referral to a haematologist.

  • Agreed - iron is not something that should be ignored.

    If september2015 does need or want to take iron again, I sugegst considering Ferritin and/or Haem (also spelled heme) supplements. They keep the iron itself in a form that should cause few, if any, issues through the gut. But see doctor first.

    And raise a Yellow Card report!

  • Thanks Helvella. I am seeing another internist tomorrow and hope that would be helpful to me.

  • Hi Aspmama, thank you for responding. I live in a small Caribbean islands, which does have good doctors, but I doubt if there is any haematologist here. I have been anemic most of my adult life with low hemoglobin, but now that I am going through menopause, Hb was at 12, but Ferritin was at 9. In mid 2013 my Ferritin was 19.9 and the dr. had put me on Ferrous gluconate and I was fine with that. Ferritin went up to 93 within 7 months and when I stopped taking the supplement , by Sept 2014 it went down to 40, but my dr. didn't ask me to continue the supplements, and from there in mid May 2015 I got sick with shortness of breath. It wasn't until end of July when a friend dr. (not my regular doctor) told me check for iron and ferritin that I got it checked. but because the range is from 6-200+, 9 looked ok. But now I understand that anything below 20 is iron deficiency anemia.

    From the past year or more my diet has not been balanced, I don't eat a variety of food and have had very little iron rich food. Plus I don't take any multi-vitamins. I am guessing that could be the cause of my low iron. My Vitamin D was low and after supplements it is now at 30, but my other minerals etc. were good.

  • Your serum ferritin should be above 60. Do you know what your haemoglobin count is?

    Ignore "normal" ranges, they are pretty meaningless - to establish them they tested a range of people, some of whom were ill.

  • HiAspmama, my hemoglobin count was 12.1 in May. Normally it ranges between 10.5 - 11.9.

  • Shortness of breath is a symptom of iron deficiency. It may not be the tablets causing it but the underlying deficiency. But worth discussing with your doctor.

  • Thanks for responding Laura. I do have iron deficiency anemia, but somehow feel that my Dr. is not doing all what she needs to do for me. I am going to another internist tomorrow to check it out.

  • Hi,

    You don't mention if you are buying supliment you buy over the counter or if they are prescribed, i for years had very shallow breathing & i accepted that was just what happened to me as i got older I'm 56, but my doctor diagnosed me as pernicious anaemic 5 years ago & i get B12 injections every 8 weeks my breathing & other niggly wee things, i never even realised was happening to me, all sorted themselves out, my breathing now normal, I've never experienced any side effects like you seem to have, i suggest you don't self medicate only go by what your doctor gives you, wishing you a speedy recovery take care H x

  • HI Honor1A, I am 50. I am getting my iron supplement prescribed by my Dr., but the same may also be available over the counter. My B12 was at 289 at the beginning of Sept. and I have taken 3 shots in 3 weeks. Was taking sublingual tablet once daily, but after the episode with Ferrous Sulphate, that also seemed to cause problems. Got Sundown liquid (which agreed with me previously), but seems like isn't agreeing with me now.

  • Hi September 2015, I don't understand the numbers you quote what they are & what they should be etc also sublingual tablets, I put my total faith in my Doctor's, if it was 6 years ago maybe not as doctor's back then both approached there retirement, I now have two doctor's in there late 20's early 30's & can't do enough for me, the conditions I suffer are underactive thyroid, pernicious anaemia & fibromyalgia previous doctor's had me on combination of medication not really doing much for me, with the new doctors I expressed that I wanted to come off as many medications as I could, as I felt I was loading my system with toxins with possible future health risks & had the full support from my doctor's & I occasionally require short periods of time I need medications like just now for my bad back & fibromyalgia pain (severe episode just now) so I'm taking 600mg of Ibrufen 3 times a day & in between I'm taking paracetamol 2 tablets 4 times a day I hope only to be on these for 3 days certainly not more than 5 days then back to only taking paracetamol as & when I feel it necessary, B12 I get every 8 weeks it originally was at 13 week intervals but felt by week 6 or 7 I was so exhausted, needing to sleep most of the day, I felt I was effectively losing 4 or 5 weeks out of 13 so that's why I get B12 at 8 week intervals & I don't inject myself or take any sublingual tablets & I cope very well with my medications that I take, wishing you well xx

  • Thanks Honor. My dr.'s nurse gives me shots of only 1000 mg B12. I have taken it once weekly for last 3 weeks. My B12 blood test count was at 289. I am not sure if my doctor is doing enough for me. I might considering changing doctors. I also understand that iron deficiency anemia can result in anxiety, which also I seem to be experiencing. Anyone been in my condition? Does the anxiety get better when iron and B12 numbers go up?

  • Here at this link drugs.com/cdi/ferrous-sulfa... it lists difficulty breathing as one of the severe allertgic reactions to ferrous sulfate.


  • I got a B12 shot yesterday morning at my doctors and within an hour started feeling difficulty breathing. The same had happened when I had got it done last week, but I thought that was due to Ferrous Sulfate as I had started taking that around the same time. The inject my doctor has is made with cobalamin, so it is possible that it could be causing me reaction. As the sublinguial tablet and liquid I got also had the same ingredient, I guess they also gave me some trouble. A couple years ago I had got the shots at a different place, their injection was based on hydroxocobalamin and that hadn't caused any problem for me. Has anyone else has had any allergic reactions to cobalamin B12 injections?

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