What is the safest oral (PO) birth control?

Safest Oral Birth Control

Progestin-only pills (POPs) are the safest oral contraceptive option because they lack estrogen and therefore do not increase the risk of venous thromboembolism, stroke, or cardiovascular disease. 1, 2

Why POPs Are Safest

Progestin-only pills carry minimal serious health risks compared to combined hormonal contraceptives (CHCs). The key safety advantage is the absence of estrogen-related complications:

• No increased VTE risk: POPs do not increase venous thromboembolism risk in healthy women (RR 0.90,95% CI 0.57-1.45), making them appropriate for women with contraindications to estrogen including those with positive antiphospholipid antibodies or history of thrombosis 1
• No cardiovascular risk: Unlike combined oral contraceptives which increase VTE risk from 2-10 events per 10,000 women-years to 7-10 events per 10,000 women-years, POPs are associated with rare serious risks 2
• Safe for high-risk populations: POPs are appropriate for breastfeeding women, women over 35 who smoke, and those with hypertension or history of thromboembolism 1, 3

Important Safety Caveats

While POPs are the safest, they have significant practical limitations:

• Lower effectiveness: Typical use failure rate is approximately 5-9% per year compared to 0.1% for combined pills with perfect use 3, 2
• Strict timing requirements: Must be taken within 3 hours of the same time daily (traditional POPs) or within 24 hours (drospirenone POP) 4, 1
• Irregular bleeding: Most common side effect due to inconsistent ovulation inhibition 1, 3
• Ectopic pregnancy risk: If pregnancy occurs, 5-10% are ectopic 3

When Combined Pills May Be Considered

For healthy women without cardiovascular risk factors, combined oral contraceptives containing ≤30 mcg ethinyl estradiol may be acceptable alternatives:

• Better effectiveness: Perfect use failure rate of 0.1% vs 0.5% for POPs 3
• More forgiving timing: Can be taken within 24 hours of scheduled time 4
• Better cycle control: More predictable bleeding patterns 1

However, combined pills increase VTE risk and should be avoided in women who smoke (especially over 35), have hypertension, history of thromboembolism, or other cardiovascular risk factors 3, 2, 5.

Clinical Algorithm for Selection

Start with POPs for:

• Any woman with estrogen contraindications (thrombosis history, smoking over 35, hypertension, migraine with aura) 1, 3
• Breastfeeding women 1
• Women prioritizing safety over effectiveness who can maintain strict timing 1

Consider combined pills (≤30 mcg EE) only if:

• No cardiovascular risk factors present 5
• Patient requires higher effectiveness 2
• Patient cannot maintain strict daily timing 1
• Irregular bleeding is unacceptable 1

Counsel all patients that long-acting reversible contraceptives (IUDs, implants) offer both superior safety profiles and effectiveness (<1% failure rate) compared to any oral method 2.