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Thyroid UK
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Does anyone take Sertraline and has it effected your Thyroxine absorption?

31 Replies

As it is an antidepressant and you are hypothyroid, did they check your Free T3 and Free T4 first?

The reason being is that if your T3 is too low - despite taking levothyroxine - they should offer you T3 which is a thyroid hormone and it enables our body to function as normal. The heart and Brain need the most T3.

Levothyroxine is T4 - T4 is an inactive hormone and has to convert to T3. Is your levo dose optimal? It has to be and the doctor should ensure you have sufficient to convert to T3.



My TSH 0.17 0.27-4.2

Free Thyroxine 21.3 12.0-22.0

Free T 3 3.3 3.1-6.8

I know my T3 low but neither endo or doc will prescribe T 3.

The Natural doctor prescribed selenium supplements to try and up T3 conversion ( not sure about this.)


Might work, might not. There are so many reasons for poor conversion. Worth a try, though. :)


Thank you grey goose. Do you think increasing vit d3 may help as well?😊 vit d 58 50-200 it was 31 at beginning of the year. I’m taking 5,000 a day.


It might. You can't predict these things, you just have to try. :)

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Thank you 😊 x


You're welcome. :)


I struggled to get my Vit D levels up , the better you oral spray was the only thing that made a significant difference. I used the one which contains K2 which should be taken alongside Vit D. My level only went up from 38 to 51 in six months of tablet supplements and spending lots of time in the sun last summer. I changed to 3000 units via the spray and in 3 months it had risen to 90 so a significant improvement.


Oh wow! I’ve just bought viridian liquid drops. After next blood test, I will try spray if my levels havent risen.😊


The liquid drops might be ok if you can hold them in your mouth and absorb them via the oral mucosa. With the spray you just squirt it onto the inside cheek in your mouth. I'm not familiar with the drops so not sure how you take them.

If you have auto immune thyroid problems you may have low stomach acid which means your gut function is impaired so it is difficult to absorb vitamins if you take tablets, that's why the oral sprays and possibly the drops, work better.

My son who is coeliac had exactly the same problem trying to raise his vit D levels, the spray has helped enormously.

Good luck! and good health! :)

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Thank you! The drops are in sunflower oil and orange oil. Will try holding it in mouth. I get quite a lot of heartburn, is that a sign of low stomach acid?


It certainly was with me, my gp gave me omeprazole which i later discovered just made matters worse, as that reduced the acid even more ( and probably contributed to even lower vitamin levels) so I slowly weaned myself off that. I also discovered that low stomach acid can cause the sphincter valve at the top of the stomach to only partially close which causes the acid to reflux upwards and cause the burning sensation.

If I get reflux now I take apple cider vinegar , the organic sort with the 'mother' ( about a dessert spoonful ) diluted in glass of water before meals, or sometimes before bed to stop reflux when I'm lying down, I also find lying on my right side causes fewer problems.

Hope that helps, get back to me if you need any more info, this forum is great because someone will always come along and help you out. :)


Thank you Knitwitty, I’m getting heartburn a lot. I’ve had an endoscopy and impedence test with manometry. Endoscopy said I had a lax valve but manometry said I didn’t. It also said I didn’t seem to have excess acid in oesophagus. Frustrating when you can’t get to the bottom of problem!


Hi again Sunnydevon, I've just read further down the page that you take magnesium, I also take this and I use a Better You magnesium lotion on my neck and shoulders at night before bed about a teaspoonful rubbed in. Magnesium aids sleep and is relaxing, and I always find that reflux seems to be worse if you are uptight and anxious ( that might just be me though!)

You can buy oil from them to spray on your skin but that feels a bit sticky on my skin whereas the lotion is quite pleasant to use.


Knitwitty, I have been suffering terribly lately from anxiety. I have struggled to know what to do for the best. I am 53 so menopause is probably playing it’s part. I didn’t know whether to try HRT or antidepressants. My GP was keen on the anti depressants so I have given in. Thank you for your reply-really appreciation it😊


I'll PM you with a more detailed reply regarding my own situation and how I dealt with it. :)


Oh thank you!😊x


which brand of the vitamin d spray do you use?


Better you it also contains K2 which is needed to direct calcium to your teeth and bones and not soft tissue. It is very pleasant and tastes minty.:)


Many of us find the vitamin D mouth spray is much more effective. It's absorbed in the mouth, therefore avoiding poor gut function


I've not taken it myself, but a 2009 study looking at that issue, concluded that "Neither fluoxetine nor sertraline was associated with clinically significant changes in thyroid function or thyroid autoimmunity in either primary hypothyroid or normal thyroid function patients with depression"


Re. selenium, it plays a part in a range of functions including the synthesis and metabolism of thyroid hormones, and a low level will negatively impact T4 to T3 conversion; but I doubt that supplementing an already optimal level will make much difference to conversion, nor will it compensate for any other nutritional deficits impacting on thyroid functioning. Were you tested for a range of nutritional deficiencies before supplementing with selenium?


Yes I had quite a range of bloods done.


Thanks MaisieGray there are many naysayers who have posted that once our thyroid levels are optimal we will not feel low; every time I try to wean myself off prozac I turn into a( n even more) shouty entitled filth spouting hag than I already am... So I didn't take any notice - but nice to have the science bit pointed out. 👍

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These meds are very hard to stop. I've been trying to stop sertraline, gradually lowering my dose, for *years*. I found a good support group online and have been following their advice. I tried a rapid taper off a previous SSRI (over, umm, 4-5 months?) and I was a mess. This is working better and I'm functioning well almost all of the time.


Rapunzel I think that's an excellent point; and it's important to remember that whilst the impact of low thyroid hormones can obviously be wide-ranging, nevertheless other health issues can also arise independent of it - even optimally medicated and tickety boo, we can develop mental ill health or indeed anything else. Not everything is down to being under-medicated.


You need vitamin D, folate, ferritin and B12 levels to be optimal for good conversion of FT4 to FT3

Currently your FT3 is terrible

Do you have autoimmune thyroid disease (Hashimoto's) diagnosed by high TPO or high TG thyroid antibodies?

Vitamin D is still far too low. Aiming to improve to at least 80nmol and around 100nmol may be better .

Vitamin D mouth spray by Better You is good as avoids poor gut function.

It's trial and error what dose each person needs.

Once you Improve level, very likely you will need on going maintenance dose to keep it there.

Retesting twice yearly via vitamindtest.org.uk

Local CCG guidelines


Government recommends everyone supplement October to April


Do you supplement any magnesium?







Do NOT supplement any vitamin K if you take any blood thinning medication


Vitamin C and bones


The importance of sunshine


For full Thyroid evaluation you need TSH, FT4 and FT3 plus both TPO and TG thyroid antibodies tested. Also extremely important to test vitamin D, folate, ferritin and B12

Ask GP to test folate, B12 and ferritin

Low vitamin levels are extremely common, especially if Thyroid antibodies are raised

Recommended on here that all thyroid blood tests should ideally be done as early as possible in morning and fasting. Last Levothyroxine dose should be 24 hours prior to test, (taking delayed dose immediately after blood draw). This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip, best not mentioned to GP or phlebotomist)

Is this how you do your tests?

Private tests are available. Thousands on here forced to do this as NHS often refuses to test FT3 or antibodies or all vitamins


Medichecks Thyroid plus ultra vitamin or Blue Horizon Thyroid plus eleven are the most popular choice. DIY finger prick test or option to pay extra for private blood draw. Both companies often have special offers, Medichecks usually have offers on Thursdays, Blue Horizon its more random

Yes many on her take selenium. It's supposed to improve conversion of FT4 to FT3

Daily vitamin C can help support adrenals too


I take magnesium 300mg per day. Also 500mg Vit C . 5,000 iu of d3 , vit k spray (better you) and Omega-3. Also selenium 😊

Serum vit B12 level 651ng/L(>180)

Serum folate >20.0ug/L(3.9-20.0)

Thank you for your reply 😊


1000mg vitamin C might be better

Vitamin D mouth spray- as discussed above

Supplementing a good quality daily vitamin B complex, one with folate in not folic acid may be beneficial.


B vitamins best taken in the morning after breakfast

Recommended brands on here are Igennus Super B complex. (Often only need one tablet per day, not two). Or Jarrow B-right

If you are taking vitamin B complex, or any supplements containing biotin, remember to stop these 7 days before any blood tests, as biotin can falsely affect test results




Just read your previous posts

See you had RAI for Graves

So trying strictly gluten free diet may help

Trying gluten free diet for 3-6 months. If no noticeable improvement then reintroduce gluten and see if symptoms get worse



Meanwhile email Dionne at Thyroid Uk for list of recommended thyroid specialists. You are very likely going to need addition of small dose of T3

But getting all four vitamins optimal and trying strictly gluten free diet diet FIRST is recommended

Roughly where in the UK are you?

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Hi SlowDragon, I am in Devon. Near Exeter. Had coeliac test recently that was negative. Have been low in B12 in the past and had loading injections. It’s mid range now as supplementing with spray. Will try gluten free.


Thousands on here, including myself, test negative for coeliac, but turn out to be gluten intolerant

The only way to know is to try it. It does need to be absolutely strictly gluten free to be effective


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