Thanks for query,
The trigestral pills have 2 types active & non active pills .Active pills have 3 different colors having different composition of oestrogen & progesteron hormone to match the normal menstrual pattern.
Have a hormone composition very similar to the physiologic levels of the during menstruation
. The red non active pills is a placebo or reminder pills. This will complete your monthly cycle so that you may not missed it or forgot to take it.
You can choose any brand all have same action.