CONCOMITANT USE OF CONJUGATED ESTROGENS AND MICRONIZED PROGESTERONE INCREASE HDL-C AND TRIGLYCARIDES AND DECREASE LDL-C COMPARED TO PLACEBO AND IMPAIR GLUCOSE TOLERNCE. IT INHIBITS CYCLOSPORINE METABOLISM LEADING TO ITS TOXICITY. PHENYTOIN, RIFAMPICIN, GRISEOFULVIN, TRETINOIN, CARBAMAZEPINE, PHENOBARBITONE MAY ENHANCE PROGESTERONE CLEARENCE AND HENCE REDUCE ITS EFFICACY AS ORAL CONTRACEPTIVE( WHERE IT IS USED AS ONLY DRUG) AND OTHERWISE.