Hi danie02

There are possible negative interactions between alpha-lipoic acid, taken as a supplement, and Levothyroxine - Possible Interactions with: Alpha-Lipoic Acid | University of Maryland Medical Center.

Your prescribing doctor should be able to discuss this with you.

Thanks kiwi. I just had my dose lowered, so I will ask about this the next time I do bloodwork. Off to search the board for gastroparesis posts.

There is still only one study done on animals that suggested effects on tissue conversion of T4 to T3.

Effect of alpha-lipoic acid on the peripheral conversion of thyroxine to triiodothyronine and on serum lipid-, protein- and glucose levels. - PubMed - NCBI

Other sites therefore will give a "warning" about ALA because of this study. ALA has been used in Europe long before the US started using it more often. Also Japan is a big consumer. But still there are no other studies coming to light to corroborate
this 1991 study.

So one can only have thyroid testing if one is concerned about that effect and avoid really high dosing.

If you try to find studies on this topic, you need to use the alternate name for lipoic acid, which is thioctic acid.