Triphasic oral contraceptive

A triphasic oral contraceptive unit having 21 separate dosage units, adapted for successive daily oral administration comprising:

• 5-8 dosage units containing, in admixture with a pharmaceutically acceptable carrier, a combination of an estrogen and a progestogen at contraceptively effective dosages corresponding in estrogenic activity to 23-28 μg of 17α-ethinylestradiol and in progestogenic activity to 0.065-0.75 mg of norethindrone as a first phase;
• followed by 7-11 dosage units containing in admixture with a pharmaceutically acceptable carrier, a combination of an estrogen and a progestagen at a contraceptively effective dosage corresponding in estrogenic activity to 23-28 μg of 17α-ethinylestradiol and in progestogenic activity to 0.25-1.0 mg of norethindrone as a second phase;
• followed by 3-7 dosage units containing a admixture with a pharmaceutically acceptable carrier, a combination of an estrogen at a contraceptively effective dosage corresponding in estorgenic activity to 23-28 μg of 17α-ethinylestradiol and in progestogenic activity to 0.35-2.0 mg of norethindrone as a third phase;
• and optionally containing 4-8 additional dosage units free of estrogen and progestogen;
• with the provisos that the progestin dose should increase from the first phase to the second phase to the third phase, that the progestin is desogestrel at a dose in each phase of between of from 0.05-1.0 mg/day and that the dosage of estrogen is kept constant in each phase.

A triphasic oral contraceptive unit having 21 separate dosage units, adapted for successive daily oral administration comprising:

• 7 dosage units containing, in admixture with a pharmaceutically acceptable carrier, a combination of an estrogen and a progestogen at contraceptively effective dosages corresponding in estrogenic activity to 23-28 μg of 17α-ethinylestradiol and in progestogenic activity to 0.065-0.75 mg of norethindrone as a first phase;
• followed by 7 dosage units containing in admixture with a pharmaceutically acceptable carrier, a combination of an estrogen and a progestagen at a contraceptively effective dosage corresponding in estrogenic activity to 23-28 μg of 17α-ethinylestradiol and in progestogenic activity to 0.25-1.0 mg of norethindrone as a second phase;
• followed by 7 dosage units containing in admixture with a pharmaceutically acceptable carrier, a combination of an estrogen at a contraceptively effective dosage corresponding in estrogenic activity to 23-28 μg of 17α-ethinylestradiol and in progestogenic activity to 0.35-2.0 mg of norethindrone as a third phase;
• and optionally containing 7 additional dosage units free of estrogen and progestogen;
• with the provisos that the progestin dose should increase from the first phase to the second phase to the third phase, that the progestin is desogestrel at a dose in each phase of between of from 0.05-1.0 mg/day and that the dosage of estrogen is kept constant in each phase.