I have been on HRT for about 3 years. I could not function teaching when I was waking up every couple of hours and sometimes could not get back to sleep.

HRT started helping very, very quickly- a week or two if I recall. Periodically I ask my doctor and she says the new research says it's not a problem staying on them. I occasionally have a "warm flash" or two, usually in the early morning but they are so much less intrusive than the hot flashes were.

I can't think of any side effects I've experienced.