Can I take 5-htp with NDT: I’m on daily 3 grains... - Thyroid UK

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Can I take 5-htp with NDT

I’m on daily 3 grains of Thyroid -S. Still feeling anxious, worried and worthless.

GP has advised reducing NDT 3 grains since the TSH is 0.01 and T4 and T3 are at the top of the range for the first time this August.

Can I improve my mood and outlook with daily 100mg of 5-htp? Is it safe to take this with NDT until I feel better about myself. I am now 70 and have had to battle on undiagnosed for 20 years and extreme weight gain on Levothyroxine once the GP agreed 4 years ago that I was hypothyroid with antibodies.

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People require lots more information i.e. blood test results including the ranges. Thyroid plus vitamins and minerals also antibodies. Are you now losing weight and how long have you been taking 3 grains per day?


My blood results are :-

TSH 0.01 range 0.35 - 5.50

Free T4 17 “ 7.0 - 17.0

FreeT3 6.5 “ 3.5 - 6.5

Anti- TPO 41.3 9.0

Vit B12 289 150 - 900

No other tests offered at surgery.

Yes, the weight came off after changing from Levothyroxine to NDT.

Back down to 12 st after a rise to 14st.on Levo.

Still struggling to reduce weight further to be within BMI range.

Have been taking 3 grains for 18 months.


Doctors should not adjust our hormone due to the TSH alone. If we take sufficient hormones, some of us have to have a very low or suppressed TSH to feel well.

Your Vitamin B12 (a prohormone) is too low and should be nearer the top of the range. Low B12 can be the cause of dementia. GP should check that you do not have pernicious anaemia before supplementing with methylcobalamin B12 sublingual tablets.

I would never take any other medication along with thyroid hormones. As I take mine when I get up, any other supplements would take at lunch or later.

Vitamin D is also an important vitamin being a prohormone too.

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Shall try to get levels of B12, Vit D3 , ferritin and selenium checked at surgery. Many thanks.


I've taken 5-HTP for years, along with various types and combos of thyroid hormone replacement meds. I've never found there is a problem taking them both. I do take them several hours apart.

Be aware that 5-HTP may raise levels of cortisol.

I think 100mg 5-HTP is too high a dose to start on. I only take 50mg just before bed. It raises melatonin (the hormone that makes people sleepy - this was one of my reasons for taking it in the first place because I suffered with dreadful insomnia), so bedtime dosing is best. If I take a higher dose of 5-HTP than my 50mg then I get the jitters, which I think must be due to raised cortisol.

I might just be very sensitive to 5-HTP. I've read that some people on this forum take far higher doses than I do. So experimenting is key - but start low.

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Thanks. I realised on first 100mg tablet yesterday that the dose was too high as felt slightly nauseous and fell asleep mid afternoon. Switching to bedtime 50 mg today.

Thanks for your advice. Much appreciated.

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