Comparison Table: Combined Oral Contraceptives (COCs) vs Progestin-Only Pills (POPs)
Basic Characteristics
| Feature | Combined Oral Contraceptives (COCs) | Progestin-Only Pills (POPs) |
|---|---|---|
| Components | Estrogen (ethinyl estradiol 10-50 μg) + Progestin [1] | Progestin only (norethindrone, norgestrel, or drospirenone) [1,2] |
| Mechanism | Suppress LH/FSH surge, inhibit ovulation, decidualize endometrium [3,4] | Variable ovulation inhibition (desogestrel POPs more consistent), cervical mucus thickening [2] |
| Typical Use Failure Rate | 7-9% [5] | 7-9% [5] |
Initiation & Backup Contraception
| Aspect | COCs | POPs |
|---|---|---|
| When to Start | Anytime if reasonably certain not pregnant [1] | Anytime if reasonably certain not pregnant [1] |
| Backup if Started ≤5 Days After Menses | None needed [1] | None needed (norethindrone/norgestrel) [1] |
| Backup if Started >5 Days After Menses | Abstinence or barrier × 7 days [1] | Abstinence or barrier × 2 days (norethindrone/norgestrel) or × 7 days (drospirenone) [1] |
| Pre-Initiation Testing | Blood pressure measurement required [1] | None required [1] |
Key Contraindications & Restrictions
| Condition | COCs (Category) | POPs (Category) |
|---|---|---|
| Breastfeeding <6 weeks postpartum | Category 4 (unacceptable risk) [1] | Category 3 (risks usually outweigh benefits) [1] |
| Breastfeeding 6 weeks-6 months | Category 3 [1] | Category 1 (no restriction) [1] |
| Age ≥35 + smoking ≥15 cigarettes/day | Category 4 [1] | Category 1 [1] |
| History DVT/PE | Category 4 [1] | Category 2 [1] |
| Migraine with aura (any age) | Category 4 [1] | Category 2 [1] |
| Hypertension (SBP ≥160 or DBP ≥100) | Category 4 [1] | Category 2 [1] |
| Current breast cancer | Category 4 [1] | Category 4 [1] |
| Active viral hepatitis | Category 4 [1] | Category 3 [1] |
| Enzyme-inducing anticonvulsants | Category 3 [1] | Category 3 [1] |
| Rifampin/rifabutin | Category 3 [1] | Category 3 [1] |
Clinical Advantages & Disadvantages
| Aspect | COCs | POPs |
|---|---|---|
| Non-Contraceptive Benefits | Reduced ovarian/endometrial cancer risk, improved acne, menstrual regulation, reduced dysmenorrhea [5,1] | Suitable for breastfeeding women, no estrogen-related side effects [2] |
| FDA-Approved for Acne | Yes (4 formulations: norgestimate/EE, norethindrone/EE, drospirenone/EE combinations) [1] | No [1] |
| Bleeding Pattern | Predictable withdrawal bleeding [1] | Irregular bleeding most common complaint; variable patterns [2,6] |
| Cardiovascular Risk | Increased VTE risk, contraindicated in high-risk patients [1,5] | Minimal cardiovascular risk [2] |
| Timing Sensitivity | 7-day backup window if late start [1] | 2-day backup (traditional POPs); must take same time daily [1,2] |
Progestin Generations in COCs
COCs contain different progestin generations, all yielding net antiandrogenic effects when combined with estrogen 1:
- First-generation: Norethindrone, ethynodiol diacetate (most androgenic alone) 1
- Second-generation: Levonorgestrel, norgestrel 1
- Third-generation: Norgestimate, desogestrel (less androgenic) 1
- Fourth-generation: Drospirenone (spironolactone analogue, antiandrogenic) 1, 3
Special Populations
| Population | COCs | POPs |
|---|---|---|
| Postpartum (non-breastfeeding) | Avoid first 21 days (Category 4); caution days 21-42 if VTE risk factors [1] | Can initiate anytime [1] |
| Postpartum (breastfeeding) | Avoid first 3 weeks (Category 4); generally avoid week 4 (Category 3) [1] | Preferred option after 6 weeks [2] |
| Bariatric surgery (malabsorptive) | Category 3 (absorption concerns) [1] | Category 3 [1] |
| Inflammatory bowel disease | Category 2-3 (depending on VTE risk) [1] | Category 2 [1] |
Management of Irregular Bleeding
For both COCs and POPs, NSAIDs for 5-7 days may reduce unscheduled bleeding 6. If bleeding persists and is unacceptable to the patient, counsel on alternative methods rather than continuing an unsatisfactory regimen 6.