Re: Can the pill effect your TSH?
BCPS can effect your Total T4 level, but not your FT4, at least not directly. The estrogens bind to thyroid hormones (TT4) and as a consequence can lower your FT4, which would mean yes, you'd need more thyroid. I would surmise that if your FT4 were lowered your FT3 would also come down and your TSH would likely go up.
A foolish consistency is the hobgoblin of little minds.