ALL hormonal items should be cycled to some degree and this includes pharmaceutic offerings for chronic disease (i.e. - thyroid disease states, et al...). For anyone (inclusive of doctors) who suggest the contrary, this merely displays a dearth of understanding of the endocrine system at large and it is a sure-fire reason why we suffer as a society at large from a state of endocinologic disarray.
The issue with green tea is that it also harbors pro-estrogenic (albeit phytoestrogenic) properties, so this should be used with caution as well. Again, anything possessing any level of endocrine disruption should be used with some thought design. Its not as easy a profession as many profess (albeit incorrectly too often).
I encourage complete endocrine profiles yearly - and do not care the hefty price tag that comes with them. As many are very willing to spill all these extra dollars into so many other things, with the quick and dramatic changes that occur with hormones, this should be an investment everyone acknowledges for their health.
Of course, people should play the odds. Many of my patients, I encourage as frequent as quarterly evaluations if not even more frequently like bi-monthly.