When most people say "the pill," they are referring to combined hormonal birth control pills: a daily oral contraceptive containing both estrogen and progestin. It remains the most widely used form of reversible birth control in the United States, and for good reason. It is reliable, flexible, and offers significant health benefits well beyond pregnancy prevention.
However, it is also the method most commonly misunderstood. Let us separate the facts from the decades of accumulated myths.
How Combined Pills Work
Combined pills prevent pregnancy through three coordinated mechanisms:
- Suppressing Ovulation: The primary mechanism. The combination of estrogen and progestin signals to your brain that you have already ovulated, preventing your ovaries from releasing an egg each month.
- Thickening Cervical Mucus: Progestin thickens the mucus at the cervix, creating a barrier that makes it extremely difficult for sperm to pass through.
- Thinning the Uterine Lining: This makes the uterine environment less receptive to implantation.
With typical use (accounting for real-world human behavior like occasionally forgetting a pill), combined pills are 93% effective. With perfect use, they are over 99% effective.
Benefits Beyond Birth Control
One of the most compelling aspects of combined pills is their therapeutic versatility. Millions of women take them for reasons that have nothing to do with preventing pregnancy:
- Lighter, Shorter, More Regular Periods: The pill gives you predictable cycles and dramatically reduces menstrual flow and cramping.
- Acne and Unwanted Hair Growth: By reducing androgen levels, combined pills effectively treat hormonal acne and hirsutism.
- Reduced Cancer Risk: Long-term use is associated with a significantly decreased risk of ovarian cancer, endometrial (uterine) cancer, and colorectal cancer. This protective effect can persist for years after you stop taking the pill.
- Endometriosis and Fibroid Symptom Management: Combined pills are a first-line treatment for managing the pain and heavy bleeding associated with endometriosis and uterine fibroids.
- Migraine Frequency Reduction: For women who experience menstrual migraines (migraines without aura that are triggered by hormonal fluctuations), continuous pill use can reduce their frequency.
How to Take Them
Most combined pill packs come in a 28-day cycle:
- 21 active pills containing hormones
- 7 placebo (inactive) pills during which you will have a withdrawal bleed (this mimics a period but is not a true menstrual period)
You take one pill at approximately the same time each day. Unlike progestin-only pills, combined pills have a more forgiving timing window. Being a few hours late is generally not a problem, though consistency improves effectiveness.
Skipping the Placebo Week
If you prefer to reduce or eliminate monthly bleeding, your provider can instruct you to skip the placebo pills and start a new active pack immediately. This is medically safe and increasingly common. ACOG confirms there is no health requirement for a monthly withdrawal bleed.
Who Should Not Take Combined Pills
Combined pills are safe for the vast majority of women. However, because they contain estrogen, they carry a small increased risk of blood clots, heart attack, and stroke. You may not be a good candidate if you:
- Are 35 or older and smoke (or use nicotine products)
- Have high blood pressure or high cholesterol
- Have a history of blood clots or blood clotting disorders (like Factor V Leiden)
- Experience migraines with aura (visual disturbances before the headache)
- Have certain liver or gallbladder disease
- Have a history of breast cancer
- Are less than 21 days postpartum (due to elevated clot risk after childbirth)
The risk of blood clots also increases temporarily after surgery or during extended travel (like long flights). If any of these apply to you, your MomDoc provider will discuss safer alternatives, such as progestin-only pills, IUDs, or the implant.
Common Side Effects
Most side effects are mild and resolve within the first 2–3 months as your body adjusts:
- Nausea: Taking the pill with food or at bedtime often helps.
- Breast Tenderness: Usually temporary.
- Breakthrough Bleeding: Spotting between periods is common in the first few cycles.
- Headaches: Typically mild. If they worsen or develop aura symptoms, contact your provider immediately.
What to Do If You Miss a Dose
The instructions in your pill pack are the most accurate guide for your specific formulation. As a general rule:
- Missed 1 pill: Take it as soon as you remember, even if that means taking two pills in one day. No backup method needed.
- Missed 2 pills in a row: Take 2 pills as soon as you remember and 2 the next day. Use a backup method (like a condom) for the next 7 days.
- Missed 3 or more pills: Use a backup method immediately and contact your MomDoc provider for guidance on whether to restart the pack.
Choosing the Right Pill
There are dozens of combined pill formulations, each with slightly different ratios of estrogen and progestin. Finding the right one is not guesswork. Your MomDoc provider will consider your health history, your symptoms, and your goals to recommend a specific formulation. If the first one does not feel right after a few months, we adjust. The process is collaborative.
This content is for informational purposes only and does not replace professional medical advice. Always consult your MomDoc provider to determine which birth control method is safest and most effective for you.