Not chamomile. And chrysanthemum flower has some of the same things as chamomile that lower thyroid.

My wife gets cold and her thyroid swells from chamomile. She takes skullcap (scutellaria) for a relaxing tea and that doesn't seem to bother her. Passionflower contains the same type of relaxants as skullcap, but her skin gets sensitive when she drinks passiflora - not a thyroid thing as far as she can tell, just an individual reaction.