Is it ok to take a 200mg dose of progesterone tablets vaginally in the night/?

Just to clarify - what sort of tablets are you intending to use vaginally? What are you using progesterone for?

In the United States the recommended dose of progesterone is:

# For oral dosage form (capsules):

* For preventing estrogen from thickening the lining of the uterus (endometrial hyperplasia) when taking estrogen for ovarian hormone therapy in postmenopausal women:
o Adults—200 mg a day at bedtime during the last fourteen days of estrogen treatment each month. Although other schedules are possible, usually treatment begins either on Day 8 through Day 21 of a twenty-eight-day cycle or on Day 12 through Day 25 of a thirty-day cycle. Your doctor may ask you not to take progestins or estrogens for the last five to seven days of each month. Sometimes your doctor may increase your dose to 100 mg in the morning to be taken 2 hours after breakfast and 200 mg to be taken at bedtime.

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* For treating unusual stopping of menstrual periods (amenorrhea):
o Adults—400 mg a day in the evening for ten days.

# For vaginal dosage form (gel):

* For treating unusual stopping of menstrual periods (amenorrhea):
o Adults and teenagers—45 mg (one applicatorful of 4% gel) once every other day for up to six doses. Dose may be increased to 90 mg (one applicatorful of 8% gel) once every other day for up to six doses if needed.
* For use with infertility procedures:
o Adults and teenagers—90 mg (one applicatorful of 8% gel) one or two times a day. If pregnancy occurs, treatment can continue for up to ten to twelve weeks.

http://www.drugs.com/cons/progesterone.html