How long does it take for daily 25 mg/levothyroxine intake to leave your system after ceasing intake? have hashimoto's disease and experience extreme weight loss etc. this was the second incident that occurred after going on and then going back on the med

It : It could take up to 3 months for levothyroxine to fully clear your system. This medication typically takes a few weeks to be effective in the body. It is not advised to halt taking this medication, and may doctors will typically recommend weaning the doses, decreasing intake until you are off.

Possible other issue: 25 mcg levothyroxine is a very small dose. It would be very unlikely that this dose would cause high thyroid levels and excessive weight loss. However, people with hashimoto's can sometimes experience temporary high thyroid levels because of increased inflammation of the thyroid (hashitoxicosis).