levothyroxine side effects

I have just switched from levo to the non-generic Sunthroid.
My quesion is about the side efffects with the genric version- i had excessive drowsinees- i felt like i was in a stupor-i been on the synthroid  just a few days but can tell am less groggy and more alert.
What is that about?

[Thypatient]

Sounds like you're just better suited to be on Synthroid.  That's great if it's working already.

[kitty9309]

Brand name thyroid meds are more consistant in the dose. That is, they really do have the actual anount of active ingredient that it says it has. (ie. 100 mcg-100 mcg)

Sounds obvious, but generics can differ by as much as 25% in active ingredient and the FDA is ok with that! (ie. 100 mcg generic levothyroxine could have between 75-125 mcg)

This really matters with thyroid meds because the TSH needs to be kept in a very narrow range and a small difference in the amount of t4 you get can make a big difference in the TSH and how you feel.

Also it is possible that a filler in the generic didn't sit well with you.

Glad you are beginning to feel better.