5HTP and TSH

[pdpdpd]

I have taken Synthroid for approximately 18 years.  When I started taking 5-HTP, 50 mg at night for perimenopausal sleep problems, my TSH became abnormally low on my routine annula tests.  Is there cause for concern?  Could the 5-HTP also be suppressing ACTH or other pituitary hormones?

[Mark Lupo, M.D.]

I don't know of a link here  -- would have to do some research -- but have not seen in clinical practice.  Doubt it is effecting the ACTH.  Would retest TSH to make sure it's a real change and re-eval synthroid dosing and other meds known to interfere with synthroid.  It's possible the 5htp slows the clearance of synthroid but I am not certain - medications like zoloft have been linked to the opposite, so I would have thought 5HTP would increase clearance and not slow it ((ie would have lead, if anything, to a higher TSH).

[GravesLady]

HTP suppresses thyroid hormones, estrogen by whatever means, interferes with absorption. However if you are constant taking them and levels are adjusted accordingly going by FTs with TSH, then there is nothing to be concerned about.  Estrogen does not interfere with FTs (Free) levels.

[mk8]

A related discussion, 5-HTP was started.

[mybeautai]

A related discussion, 5 htp and tsh was started.