Birth Control Pills: What Pharmacists Wish Every Woman Knew

The two main types of pills

Combined oral contraceptives

Contain estrogen and a progestin. The most common type. Work primarily by preventing ovulation. Examples include many brand names and many generic formulations. The vast majority of women taking the pill are on combined oral contraceptives.

Progestin only pills (minipill)

No estrogen. Work primarily by thickening cervical mucus and thinning the uterine lining. Used for women who cannot take estrogen, including women who are breastfeeding, women with certain cardiovascular conditions, and women over 35 who smoke.

How to take combined pills correctly

Take one pill at the same time each day. Some packs have 21 active pills followed by 7 placebo pills. Others have 24 active pills followed by 4 placebo pills. A few are designed for extended cycling (84 active, 7 placebo) for women who prefer fewer periods per year.

Most missed dose rules are forgiving for combined pills, but with thresholds.

• Miss one pill: take it as soon as you remember, even if it means taking two pills the same day. No backup contraception needed in most cases.
• Miss two or more pills in the first week of a pack: take the most recent pill as soon as remembered. Use backup contraception (condoms or abstinence) for 7 days. Emergency contraception may be appropriate if unprotected sex occurred in the prior 5 days.
• Miss two or more pills in week 2 or 3: take the most recent pill as soon as remembered. Continue the active pills, skip the placebo week, and start a new pack of active pills.

How to take progestin only pills correctly

Progestin only pills require more precise timing than combined pills. Take at the same time every day, within a 3 hour window. If you miss the window by more than 3 hours, use backup contraception for 48 hours. There are no placebo pills, so the pack runs continuously.

Medications and conditions that reduce effectiveness

• Rifampin and rifabutin (used for tuberculosis treatment).
• Several anti seizure medications including carbamazepine, phenytoin, topiramate, and oxcarbazepine.
• St. John’s Wort.
• Some HIV medications.
• Some antifungal medications.
• Modafinil.
• Certain weight loss medications.
• Severe vomiting or diarrhea, which can prevent absorption.

Antibiotics other than rifampin generally do not significantly reduce pill effectiveness, though older guidance suggested they might. The current evidence is reassuring for most common antibiotics, though some women still prefer to use backup during antibiotic treatment as an extra precaution.

Common side effects in the first 3 months

• Breakthrough bleeding or spotting. Common and usually resolves by month 3.
• Nausea. Often improves with taking the pill at bedtime.
• Headache.
• Breast tenderness.
• Mood changes.

Most side effects resolve within 2 to 3 months. If they persist or are severe, a different formulation often resolves them. There is no single best pill; different formulations work better for different women.

Serious side effects to know

Combined hormonal contraceptives slightly increase risk of blood clots. The absolute risk is small for most women but rises significantly with certain risk factors.

• Smoking, especially over age 35.
• Obesity.
• Personal or family history of blood clots.
• Certain inherited clotting disorders.
• Prolonged immobility, including after surgery or long travel.
• Migraine with aura.

Signs of a possible clot that warrant emergency care: severe leg pain or swelling, sudden shortness of breath, chest pain, sudden severe headache, vision changes, or weakness.

Alternatives to consider

Birth control pills are not the right method for every woman. Several alternatives have become more popular in recent years.

• IUDs (hormonal or copper). Effective for 3 to 10 years depending on the device. Highest efficacy of reversible methods.
• Implant (Nexplanon). Single rod in the upper arm, effective for 3 years.
• Injection (Depo Provera). Every 3 months.
• Vaginal ring (NuvaRing, Annovera).
• Patch (Xulane, Twirla).
• Permanent options including tubal ligation and vasectomy for partners.

Where pharmacy fits

Free pharmacist consultations on contraception choices, missed dose handling, drug interactions, and side effect troubleshooting. Serving Hattiesburg, the Pine Belt, Central Mississippi, and South Mississippi.

When to call a pharmacist

• You missed multiple pills and are unsure how to handle it.
• You are starting a new prescription medication while on the pill.
• Severe vomiting or diarrhea has occurred.
• You are experiencing side effects that are not improving by month 3.
• You are planning to switch methods.
• Smoking, age, or other risk factors have changed.
• You are breastfeeding and unsure about your contraception.

This article is for general information only and is not a substitute for personalized medical advice. Before starting or changing any medication, including over the counter products and supplements, talk with your pharmacist or physician about your specific situation.