Mercury Pharma Levothyroxine Experiences

I would be interested in feedback on people's experience with Mercury Pharma 25mcg Levothyroxine.

It is obvious that some people have not got on well with this make of Levo and I would like to hear about any specific symptoms that were experienced and what changed when you replaced the Mercury tablets with an equivalent does of an alternative, such as Activis?

The reason for asking is that, after I replaced Mercury tablets with an equivalent dose of Activis Levo, I felt significantly better mentally (less anxious, better concentration). However - and it may be coincidental - my heart-rate dropped (typically 44BPM), blood pressure is lower and I am extremely tired in the afternoons.

I am not entirely convinced that there is a connection between this and replacing the Mercury tablets with an equivalent dose of Activis, which is why I would like to find-out the "symptoms" that others experience with Mercury Levo.

39 Replies

Have definitely felt as though I am Hypo since Mercury Pharma changed Levo . Have all my old symptoms back from when I was not treated at all following sub-total thyroidectomy in 1979, though not quite as bad as then. Janet.

Today I have stopped taking Merca Pharma 25s .I have cut an Activis 50 in half . For over a year I have had a terrible bitter ,salty taste in my mouth ,this coincided with the change in name from Goldshield . I am at my wits end and my Gp has allowed me to try this method .I was already taking 100 Activis ! I do alternate 100 /125 . in regard to feeling well I seem to be up and down , I have terrible sleep issues . I had a lengthy discussion with the pharmacist last week .He has a large number of patients who are not doing well on either Activis or Pharma . He said he has told the manufacturers but they never do anything about it .He suggested that we as a group contacted them .

I will follow this thread closely as i'm sure more people are having problems with their meds.

Thank you for your reply. Maybe you can post an update in a few days, so we can see what changes you notice? I was thinking of sending a Yellow Card ( but I am not entirely sure if all of the changes that I have experienced are actually due to the switch from Mercury to Activis.

I've been on Mercury since I started taking levo last June - it's changed my life. Not had any problems with it at all.

Have to agree

But since starting MP Levothyroxine i have started itching and its absolutely VILE. I intend to contact my pharmacist as well as mp to try and discover if they have made any change to their fillers/coatings as i have taken mp previously to good effect

I was so unwell on MP Levo I became almost bedbound. I stopped taking my meds for 4 weeks and let myself become extremely hypo. I felt such improvement and symptoms diminished and finally disappeared.

I'm TT so had to resume Levo but insisted the Pharmacy supplied me Actavis. Symptoms returned but not so many, and not so disabling, possibly because of different fillers, my detox, and I softened the T4 by self medicating and adding in 25mcg T3 to 100mcg T4.

Many posters have reported an inability to tolerate MP but Actavis isn't winning any awards either.

I haven't added any T3 since Sunday and I have diarrhoea, thumping palpitations, carpal tunnel and internal tremors which make me worry that my legs will collapse underneath me as I walk downstairs.

Specifically the 25 microgram Mercury Pharma levothyroxine has the identical marketing authorisation (product license) as Mercury Pharma Eltroxin 25 microgram (and, when it was available, the Teva levothyroxine 25 microgram).

Although they have identical ingredients, the 50 and 100 microgram Mercury Pharma levothyroxine and the 50 and 100 microgram Mercury Pharma Eltroxin products have different marketing authorisation numbers.

Heaven knows what the implications of these observations are!

I have taken several products since starting levothyroxine. Apart from times when I was taking 25 mcg tablets, I have mostly taken 50 mcg tablets - and had the following observations:

A while ago when taking Mercury Pharma levothyroxine (two a day, at bed time) I started to feel slightly over-dosed.

I switched to Actavis. After a while, a couple of weeks?, I started to feel under-dosed. Then, one day, I didn't feel a little under-dosed but profoundly so. Possibly the worst I have ever felt. And, confusingly, distinctly different to how I felt before diagnosis. (Also worse than I felt on the under-delivering Teva product.)

What do do? Between the devil and the deep blue sea!

So I am now taking one Actavis and one Mercury Pharma levothyroxine and feeling much better than on either alone.

I am lucky that I have been able to accumulate a small stock of tablets so am able to try this. Though am wondering how the pharmacist will take to supplying "four packets of levothyroxine - two Actavis, two Mercury Pharma" for my next prescription. :-)


Hi Rod

Thank you for your feedback.

It sounds like a similar experience when stopping MP 25mcg Levothyroxine.

I increased my Activis Levothyroxine from 75 to 100mcg this morning to see if this improves the hypo symptoms.

I am also taking 10mcg T3 (manufactured by Paddock) because my T3 has been low for ages and I only recently persuaded my GP to let me try T3.

I expected to feel better with the addition of T3, but maybe the Mercury Pharmacy effect is masking the usefulness of the T3? Sadly, my GP may take this as confirmation that T3 is not needed.

I would get off Actavis , I found it to be complete crap, i had migranes & was in bed , I switched to mercury & was so much better - I wouldnt adjust your dose like that either

I have posted on here before with queries about 25mcg M Pharma. I had been on 100mcg Almus (on box)(PIL says actavis) Doctor said I was over treated- I felt fine but went on to 75mcg/100mcg alternate days. Had one x 50 mcg Almus/Actavis and 1 x 25mcg M Pharma and on alternate days the 100mcg Almus/Actavis.

TSH all over the shop and now have antibodies. Endo said to go onto 100mcg daily which I have been on for a week and already no longer constipated, more energy etc.

It is difficult to know if the antibodies "muddy the waters" but having had major problems when the TEVA licence was withdrawn for their 100mcg I am inclined to think that the M Pharma levo is "not right"

PS - forgot to say I am about to start on Wockhardt and wondered if anyone has tried this and found a difference either way. Anyway I will let you all know in a few weeks (or maybe sooner) if it is good or bad. Janet.

My wife says that she did not get on well with either Wockhart or Mercury 25mcg, so it will be interesting to hear your experience.

On a related subject, this makes interesting reading:

I am not sure if this will help you but I am unable to take Wockhardt as it causes me trouble with the digestive system and am unable to take Mercury Pharma as it gives me trouble with palpitations and makes me hyperthyroid - am so confused and not sure if doctor can help - good luck!

I had problems (I think) with 25mcg wockhardt, so had my script changed to 1/2 50mcg - any brand, over a year ago.

I yellow carded a dodgy batch of Mercury t3 and a couple of months later the pharmacy gave me the same batch (obviously the one I returned to the shop with a new label on it), gave me a few problems = this time, including high blood pressure, recorded by health professionals x 3. Weight gain. They are either too strong or too weak, I dont know. I just checked the batch towards the end - too late.

Check the batches on tuk web site; they have listed all the dodgy batches that they know about.

I use a different pharmacy in the town now, so I will see how I get on.

I didn't feel right on wockhardt 25s, but started to feel better when I switched to MP and I've stayed on it as my dosage increased from 25 to 50 to 75. I think I read somewhere that wockhardt is the cheapest one for pharmacies to get so I wondered if that affected the quality, sure someone will correct me if that's not right though.

the wockhardt was ok ...I found actavis & almus to be terrible

I found Wockhart the very best of all brands.

Hi, I feel good on MP! I accidentally got actavis a couple of months ago and immediatelty got really bad digestive issues to the point where 5 days in I went back to the doc for a new prescription to get MP.

It's interesting. I get the impression that people who are exclusively on a single manufacturer's Levo do not seem to have the same type problems.

In my case, I have mostly been taking Activis 50mcg or 100mcg combined with MP 25mcg since initial Hypo diagnosis in 2010. I was surprised at the change that I felt when replacing the 25mcg BP with an equivalent amount of Activis.

However, there may be other elements in-play, as I reduced my Levo and started T3 at the beginning of December, so I may have been reacting to this change and not the dropping of MP Levo. I suspect that I will never really be sure.

I have always been advised to take the same brand for your whole dose which is another reason I've stuck with MP. I also think it's easier to monitor your levels if you're keeping that one variable constant.

I myself cannot take mercury pharma it gives me severe stomach cramps and bloating it also gives me heart flutters as well when I switched to actavis I was fine. I did discover through that mp contains acacia powder which is a type of fibre used in slimming and diet products as a filler . On the website that sells this product [ acacia] it does say it can cause side effects such as nausea stomach cramps and bloating so bearing that in mind I have asked my pharmacist to only give me actavis in future

the heart flutters could mean you need to boost your vitamin intake, dont use pills , eat fruit , I highly recommend blackberries & kiwi fruit, throughout the day & perticularly at night to help sleep

I agree. ACACIA IS EVIL. I cannot take teva or mercury pharma for that reason.

I believe that you can ask your GP to specify the manufacturer on your prescriptions.

You can ask. But it has the potential to cause problems into the future.

If your GP writes a specific make, then the pharmacist must follow that. So let us think about someone who, because they have used Boots, got Almus and get their prescription written for that. Then, for some reason, Boots cannot supply Almus. So you have to go and get a new prescription.

However, if you come to an arrangement with a friendly pharmacist, they might have been able to supply you with Actavis - which is the self-same product. Or you could have got Lloyds packaged stuff which is also Actavis.

And we have seen brands disappear not for a short period - but either for a long time, or forever.


CP Pharmaceuticals




Forley Generics




I can confirm that the arrangement with the pharmacist is the way to go. I asked the gp to specify the brand on the script and it was a huge hassle with dosages (gp only had 25s on the system? so he had to prescribe 25s?) and there was some kind of problem and I had to go back to the surgery to get them to write another script. Now my lovely pharmacist just keeps my brand for me and it is much simpler.

So it is around 5 days since I stopped the Merca 25s and started cutting Activis 50s in half .The taste in my mouth has lessened greatly . It could be coincidence and I will not be jumping up and down for a while yet but I wanted to keep you updated .

Thanks. I did not experience your taste problem, just felt generally unwell - but difficult to define really.

I have now been off the Merca for nearly 2 weeks and the horrible taste keeps coming and going so I don't think it is the Merca causing it .On the other hand I am starting to experience symptoms of being under medicated ,itching stomach ,tired less energy ,especially after exercise .Mood sinking and apathy ! .. I go back to see my Gp next

week so will see what he recommends .

I have wondered ! re-taste -if it's the Activis but how I would find that out . I do have plenty of 25s Merca ,enough to trial a full 125 using them but that would mean a massive doubling up of fillers .

The issues re Thyroid are so draining ,like the rest of you I just want to feel somewhere near the old me (: I think 10

years is long enough ! don't you ????

I have just completed an experiment re. 25mcg Mercury Pharma levo. I took 25 this morning and they have made me feel exhausted, headachey, palpations, sick, itchy and generally unwell with brain-fog as did the previous dose. I take 50 per day and 75 on alt.days and I have been cutting a 50mcg. in half and have felt OK but this morning I tried 25 again and the symptoms have all returned. I have phoned the surgery and they are sending me another brand so I will wait and see what it is. I picked a quiet day so I can rest until the symptoms settle down. What on earth is wrong with this stuff.

I was brilliant on 100mcg TEVA & 25mcg Goldshield

Moved to W Yorks & got pot-luck brands every prescription

Seen Endocrinologist - told me to go back to TEVA (April 2014) so GP agreed& chemist tried to order....& now I find TEVA doesn't make it any more...!!!

Have had trouble with Wockhardt 100mcg previously when old chemist couldn't get TEVA. Now seem to be given 100mcg Activist & 25mcg Wockhardt - but I feel worse than I did BEFORE treatment began! Feel hypo yet my bloods suggest I'm going hyper?!?!?!

GPs & chemists & Endocrinologists don't seem to understand as, to them, it's just a tablet that says 'levothyroxine sodium', but in reality it's our LIVES & our SYMPTOMS & our HEALTH & our HAPPINESS that these random drug manufacturing license changes & filler ingredient changes& company name changes are messing with....!

So frustrated& angry - but so tired& fed up of feeling ill& tired& fat& PMT & mood-swingy& fuzzy brained& headachy & menopausal& hot flushy & acne ridden& palpatations etc etc etc!

I'm well on 2x25mcg MP (same as Eltroxin), but poorly on 50mcg MP (different product licence) and well but feeling nauseous on Wockhardt 25mcg.

How can the two 25mcg brands be OK but the 50mcg brand be bad/not as good at treating you?

Is it the filler ingredients or the actual levothyroxine sodium? I've just been given 100mcg & 25mcg Mercury Pharma to wondering whether to bother?!? I was OK with Goldshield 25mcg, which I am told by Mercury Parma directly, is the same product as MP 25mcg...


I would like to add my experience recently with MP T4 and actavis. T4

I became a bit unwell about 6 weeks ago and couldn't work out why. After 3 weeks i noticed the MP 50 T4 packet had been started about 3 weeks ago and so i wondered if these 50's were a bit dodgy. I take 150 T4.

I had some spare T4 in the van which was actavis and so i started to use these for the 7 days i had enough for. I felt well after the first day. Then i had to go back to the MP and immediately felt unwell. I even tried to use the 100 T4 MP tablets to give me 150 in total, but still no good.

So i have been to the pharmacist to ask for actavis T4 for my new batch. Feel much better already.

Never been aware of issues like these before, but i have had off periods before and i reckon it must be down to the tablets at the time being compromised in manufacture.

I have started taking this brand of levothyroxine about a week ago. I am still on alternate 100/125 mcg (alongside 10 mcg liothyronine). What has alarmed me about this was I read the enclosed information leaflet and one of the side effects is that the medicine can actually increase blood glucose levels.

I am wondering whether this side effect applies to all levothyroxine since I have been on levo for the last 16 years and now I am at risk of developing diabetes.

Bit late I know but I've only just found this site. My experiences are opposite. I do better on Mercury, less well on Activis and very poorly on Wockhardt. I've just found out that Mercury have been taken over again and this last month I have been not been doing well so just wonder if something has changed.

Mercury Pharma and Tevo both have acacia which gave me bloating gas and agitated my whole digestive system. I also felt feverish and then cold. I now take almus and wockhart with no problem. The new Teva tablets are much bigger so I think would have more fillers. That is my experience anyway.

When they changed the formulation on teva to include acacia root as the filler my asthma worsened so much I ended up in hospital. I'm allergic to it and now mercury pharmacy have done the same without warning. A yellow card and nice needs to be informed. This is dangerous. I can die in an asthma attack. I'm ringing both companies to ask what research was done to ensure the safety.

The differences across brand in the potency of doses is well known and you should ask if your tyrosine is porcine or man made. The body absorbs them differently. Their is definitely a case for spot checking. Epileptic patients won over getting specific brands prescribed due to the varying effectiveness so it's about time things were better tested.

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