Oral Standard daily dose: 200-300 mg in 1 or 2 doses. 
Luteal phase defect (pre-menstrual syndrome, menstrual irregularity, pre-menopause, benign breast disease) Administered over 10 days/menstrual cycle, usually from cycle days 17-26. 
Menopause As adjuvant therapy given during the last 2 wk of treatment sequence, followed by 1 wk susp of all replacement therapy. 
Threatened abortion or prevention of LPD-related recurrent spontaneous abortions 200-400 mg, spread over 2 doses, to be taken until wk 12 of gestation. 
Threatened preterm delivery 400 mg every 6-8 hr depending on the clinical results during the acute phase, followed by a maintenance dose to be taken up until 36 wk of gestation. 
Vag Usual daily dose: 200 mg to be inserted deep into the vag. 
Partial luteal phase defect (dysovulation, irregular menstrual cycles) 200 mg over 10 days/menstrual cycle, usually from cycle days 17-26. 
Infertility associated w/ total luteal phase defect (oocyte donation) Initially 100 mg on days 13 & 14 of the transfer cycle, followed by 100 mg in the morning & evening cycle days 15-25. From day 26 onwards, in the event of conception, increase dose in wkly increments of 100 mg/day to a max daily dose of 600 mg, spread over 3 doses. Dose is maintained until day 60. 
Luteal phase supplementation during IVF 600 mg spread over 3 doses. 
Threatened abortion or prevention of LPD-related recurrent spontaneous abortions 200-400 mg spread over 2 doses taken up until wk 12 of gestation. 
Threatened preterm delivery Active treatment: 200-300 mg bid-tid in 3 days. Maintenance: 100-200 mg/day until suppression of contraction.