Thyroid UK
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Low cortisol

I have been advised to post low cortisol results because I am starting Levothyroxine 25mcg and I should not be starting it if I have low cortisol? This short synacthen test was done 4 years ago, does this need to be repeated?

At the time I had dizziness when standing from sitting, low weight and dark patches on skin. Please advise. Thank you

Short synacthen test

Baseline cortisol 231 (140 - 900)

30 minute cortisol 621

60 minute cortisol 703

4 Replies

You need the levo, so don't worry too much at this stage about interactions. I think I'm right in saying you've been prescribed 25mcg anyway (which is too low really)

Those cortisol results are ok, I would say - no reason to delay starting levothyroxine.


Oh ok. I was just so sure I have Addison's. Thanks.


Not with those results. They would have ruled it out because you responded well to the test - you had a rise from the baseline measurement of more than 200 nmol/L and the 30 min value was more than 600 nmol/L.

But being hypothyroid - as you've probably been for quite a while - has probably fatigued your adrenal glands. Hopefully now that you're being treated that will start to improve.


l had a synacthen test after low cortisol blood test, and am furious that the young Endo said nothing wrng and tried to refer me to ME/chronic fatigue - when i have had extreme female symptoms all my life. waiting for 2nd opinion - GP not helpful as knows nothing. You could speak to Pituitary Foundation who are excellent. Others on here have said synacthen a waste of time. l felt rough for days after.


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