66 years old and 14 years post menopausal. for vaginal atrophy and urethral burning do i need to take oral progesterone along with estradiol .01% cream taken 3x a week. and how long can i safely use the estradiol externally?

As long as you take the dual combination you are safe.At the age of 66 you may be advised to take a drug holiday. WhatI mean discontinue the medication for a month and if the symptoms fail to appear or are much less you may continue with no drugs. Good Luck

If you still have a uterus, I believe it's recommended that you also take oral progesterone if you use topical estrogen to avoid continually stimulating the uterine lining which is a risk factor for endometrial cancer. Your gynecologist can advise you best,however.