Combined vs progestin-only
Every pill on the chart falls into one of two families. Combined pills pair an estrogen (almost always ethinyl estradiol, "EE") with a progestin, and work chiefly by suppressing ovulation. They differ from each other in estrogen dose (10-35 mcg), which progestin they use, and pack design. Progestin-only pills (POPs, "mini pills") drop the estrogen entirely - the traditional norethindrone pills (Camila, Errin) mostly thicken cervical mucus and demand a strict same-time-daily habit, while the newer Slynd and the over-the-counter Opill are more forgiving. If you're choosing between families rather than brands, the birth control finder narrows it down by what matters to you.
Monophasic vs multiphasic
Monophasic packs deliver an identical dose in every active pill; multiphasic packs (Tri-Sprintec's three phases, Natazia's four) step the doses through the month. Contraceptively they're equivalent. Monophasic pills have two practical advantages: missed-pill rules are simpler, and you can run packs back-to-back to skip periods. That simplicity also matters when things go wrong - if you do miss one, the missed pill calculator tells you exactly what to do based on your pill type and how late you are.
Why generics are equivalent
Most rows on this chart are generics: Apri is Desogen, Sprintec is Ortho-Cyclen, Junel Fe is Loestrin Fe. The FDA approves a generic only after it demonstrates bioequivalence - the same active hormones at the same doses, absorbed at the same rate, to the same blood levels as the brand. Effectiveness and safety are identical; only fillers, coatings, and price differ. Pharmacies swap between equivalent generics routinely, which is why the name on your pack can change without your prescription changing. For more pill fundamentals, see 15 facts about the pill.
Who should avoid estrogen
The CDC's US Medical Eligibility Criteria (US MEC) rates every method against every health condition. Combined pills land in the "risks outweigh benefits" categories for: migraine with aura (stroke risk), smoking 15+ cigarettes daily at 35 or older, any history of VTE (deep vein thrombosis or pulmonary embolism), uncontrolled high blood pressure, ischemic heart disease, stroke history, current breast cancer, and the first three weeks postpartum. None of these rule out contraception - they rule out estrogen. The progestin-only column of the chart, plus IUDs and the implant, generally remain open. And one persistent myth worth retiring: routine antibiotics do not cancel the pill - check the antibiotic and birth control checker for the two real exceptions.
Frequently asked questions
Is Apri the same as Desogen?
Yes. Apri is an FDA-approved generic of Desogen: the same 30 mcg ethinyl estradiol + 0.15 mg desogestrel in the same 21/7 regimen. The FDA requires generics to be bioequivalent to the brand - same active ingredients, same doses, same effectiveness. Inactive ingredients (fillers, dyes) can differ, which is why a switch occasionally changes how a pill feels, but the contraceptive protection is the same.
What is the difference between combined and progestin-only pills?
Combined pills contain an estrogen (usually ethinyl estradiol) plus a progestin, and work mainly by blocking ovulation. Progestin-only pills (POPs or 'mini pills' like Camila, Slynd, and the OTC Opill) skip the estrogen - most work primarily by thickening cervical mucus, though Slynd also reliably suppresses ovulation. POPs are the option when estrogen is off the table: while breastfeeding, with migraine with aura, a history of blood clots, or smoking over 35, per CDC US MEC guidance.
Who should not take pills with estrogen?
Per the CDC US Medical Eligibility Criteria, combined (estrogen-containing) pills are category 4 (unacceptable risk) or 3 for: migraine with aura, smoking 15+ cigarettes a day at age 35 or older, a history of VTE (blood clots), known thrombogenic mutations, uncontrolled hypertension, ischemic heart disease or stroke history, current breast cancer, and fewer than 21 days postpartum. Progestin-only pills, the hormonal IUD, and the copper IUD remain options in most of these situations - a clinician can map your history to the MEC categories.
Does it matter if my pill is monophasic or multiphasic?
For pregnancy prevention, no - both work equally well when taken correctly. Monophasic pills deliver the same dose in every active pill; multiphasic pills (like Tri-Sprintec or the quadriphasic Natazia) step doses through the pack, loosely mimicking a natural cycle. The practical differences: monophasic pills are simpler if you miss one or want to skip periods by running packs together, and ACOG notes there is no proven symptom advantage for multiphasic formulations.
These calculators give estimates based on cycle averages and standard formulas. They are for general information only and are not medical advice. For anything concerning your health or pregnancy, talk to a qualified healthcare provider.