Thyroid UK
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Levothyroxine and supplements

Do supplements react with levothyroxine? I was diagnosed hypo 6 months ago and was prescribed 100mg from day 1.

I take my levothyroxine at night and in the morning I take Menopace, vitamin B complex and evening primrose oil. (As I'm a moody menopausal cow! Lol)

Do they affect each other? I constantly seem to want to clear my throat and Ive always been very active and fit but now feel dizzy and go clammy when I really push myself for say 30 seconds during exercise.

Is there an alternative to levothyroxine?

11 Replies

Can you post your last thyroid results then members can comment on your levels. There are alternatives but there are also other easier things to sort out that will help your thyroid use your medication better.

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I asked the doctor and she only gave me a print out showing TSH level. (Initially 18 now 3. Something)

I will ask for full results and post them when I get them. Thank you for your message


As you take your supplements well away from your levo, it should be alright.

If your FT3 isn't optimal, you shouldn't be exercising, apart from gentle walking, swimming or yoga. Exercising uses up your T3, and if you haven't got enough to begin with, it's going to leave you feeling bad.

It sounds to me as if you're under-medicated. You really need to get a printout of your results, see what's been tested, and what the results are. If you live in the UK, it is your legal right to have a copy. :)

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Thank you for your reply. Very helpful. It's just I've been active all my life and have a young son. I play hockey twice a week and don't particularly want to give it up. (Played for Wales Vets 8 years ago :-) )

I did ask my doctor for a print out of the results and she only gave me the TSH print out which has come down from the original reading of 18 to 3. Something which she said was fine.


Well, it isn't at all fine. It's still hypo. You need an increase in dose.

And, you need a full print-out of all the tests that were done - if she just did the TSH, she's wrong, but fair enough. But, she should have said so.


Also want tests for vitamin D, folate, B12 & ferritin. Common for these to be low. Get full figures in results including ranges

Do you have high Thyroid antibodies? Have they been tested? If not ask that they can be.

Alternative is private tests via Thyroid Uk website.


It's good that your TSH has come down but it's not yet where you will feel good as GG says


You need to leave 2-4 hours, depending on what you're taking, between THs & supplements.

Menopace contains soya, which reduces both the production & absorption of thyroid hormones, so taking this is counterproductive to your THs. Perhaps try black cohosh, dong quai (angelica), or red clover,. These won't be as goitrogenic as soya, if at all. Starflower/Borage oil is also higher in GLA than evening primrose. It's more expensive, but you need far less. It's also less likely to contain agrichemical residue as Borage prefers organic soils.

My NDT started to be effective once I cut out unfermented soya from my diet, & made sure I didn't take anything within 4 hours, especially other the other hormones I take. I try to remember not to take my vitamin D3 for 6 hours after THs, then take HRT after another 6 hours. If I take D3 too close to my HRT, it reduces the efficacy enough to cause hot flushes all evening, so I assume it has as much of a reducing effect on my THs. I also take T3 now, as I self-medicate, so don't have to suffer the vagaries of GPs & ignorant consultants.

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Wow. Very informative, thank you very much :-)

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You're welcome!


Ok. Was able to get a copy of my latest blood test.....

Hemoglobin A1c level IFCC stNdardised 37mmol/mol 20-41 : non diabetic range

Serum TSH level 0.17 mU/L Low

Serum LDL cholesterol level =3.6 mol

Total cholesterol:HDL ratio 3.5 ratio

Non HDL cholesterol level = 4mmol/L

Serum HDL cholesterol level = 1.6mmol/L

Serum triglycerides = 0.8 mmol/L

Serum cholesterol = 5.6mmol/L

GFR calculated abbreviated MDRD = 84mL/min original result 84 ml/min/1.73m2

Serum creatinine = 64 mull/L

Serum potassium = 4.5mmol/L

Nucleated red blood cell count 0 10*9/L

Basophils count = 0.1 10*9/L

Eosinophil count = 0.1 10*9/L

Monocytes count = 0.5 10*9/L

Lymphocyte count = 2.1 10*9/L

Neutrophil count = 2.7 10*9/L

Red blood cell distribution width 13.2%

Mean corpusc. Hemoglobin (MCH) 29.8pg

Mean corpusc. Volume (MCV) 90 fl

Hematocrit 0.43 L/L

Red Blood cell count 4.77 10*12/L

Platelet count 312 10*9

Hemoglobin estimation 142 g/L

Total white cell count 5.5 10*9/L.

All double Dutch to me except TSH has cone down

Would be grateful for any comments


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