What are the guidelines for using progesterone-only birth control pills (BCPs)?

From the Guidelines

Progesterone-only birth control pills (mini-pills) should be taken at the same time every day without breaks between packs to be effective, and are a good option for women who cannot take estrogen, including those who are breastfeeding, over 35 and smoke, have high blood pressure, history of blood clots, or migraines with aura. Common brands include Micronor, Nor-QD, and Camila, which contain 0.35 mg of norethindrone, and Slynd, which contains 4 mg of drospirenone. Unlike combined hormonal contraceptives, mini-pills must be taken within a strict 3-hour window each day (or 12 hours for Slynd) to maintain effectiveness, as noted in studies such as 1. If you miss a pill by more than this window, use backup contraception for the next 48 hours.

Some key points to consider when using mini-pills include:

• They work primarily by thickening cervical mucus to prevent sperm entry and thinning the uterine lining, with some formulations also suppressing ovulation 1
• They provide no protection against sexually transmitted infections, so condoms are recommended if this is a concern
• It typically takes 48 hours after starting for the contraceptive effect to begin, so use backup contraception during this initial period
• Side effects may include irregular bleeding, spotting, headaches, and breast tenderness

When initiating or switching to mini-pills, it is recommended to use backup contraception for 2 days, as stated in 1. Additionally, contraceptive recommendations should be personalized, focusing on the patient’s safety and reproductive life plan, taking into account medical history, sexual health, and future pregnancy intention 1. Overall, mini-pills are a safe and effective option for women who cannot take estrogen, and can be used in conjunction with other contraceptive methods, such as barrier methods or IUDs, as recommended in studies such as 1 and 1.

From the FDA Drug Label

INDICATIONS AND USAGE 1. Indications. Progestin-only oral contraceptives are indicated for the prevention of pregnancy. The following points should be discussed with prospective users before prescribing progestin-only oral contraceptives: • The necessity of taking pills at the same time every day, including throughout all bleeding episodes. • The need to use a backup method such as condoms and spermicides for the next 48 hours whenever a progestin-only oral contraceptive is taken 3 or more hours late • The potential side effects of progestin-only oral contraceptives, particularly menstrual irregularities. • The need to inform the clinician of prolonged episodes of bleeding, amenorrhea or severe abdominal pain. • The importance of using a barrier method in addition to progestin-only oral contraceptives if a woman is at risk of contracting or transmitting STDs/HIV.

The guidelines for using progesterone-only birth control pills (BCPs) include:

• Taking the pills at the same time every day
• Using a backup method if a pill is taken 3 or more hours late
• Informing the clinician of any prolonged episodes of bleeding, amenorrhea, or severe abdominal pain
• Using a barrier method in addition to progestin-only oral contraceptives if at risk of contracting or transmitting STDs/HIV 2, 2. Contraindications for progestin-only oral contraceptives include known or suspected pregnancy, carcinoma of the breast, undiagnosed abnormal genital bleeding, hypersensitivity to any component of the product, benign or malignant liver tumors, and acute liver disease 2.

From the Research

Guidelines for Using Progesterone-Only Birth Control Pills (BCPs)

• The progesterone-only pill (POP) is a highly effective method of contraception when used properly, with a very good safety profile and few contraindications 3, 4.
• A new oestrogen-free ovulation inhibitor POP, containing 4 mg of drospirenone (DRSP), has been authorized in the USA and the EU, with a hormone administration regimen of 24 days followed by a 4-day hormone-free period to improve bleeding control and maintain oestradiol concentrations 3, 5.
• Clinical trials have demonstrated high contraceptive effectiveness, a very low risk of cardiovascular side effects, and a favorable menstrual bleeding pattern with the use of DRSP-only pill 3, 6, 5.
• The long half-life of DRSP (30-34 hours) maintains the effectiveness of the preparation even if a woman forgets to take a pill on a single occasion, with studies showing that ovulation inhibition is maintained if a single pill is missed 3, 5.

Characteristics of Progestin-Only Contraceptives

• Progestin-only contraceptives (POCs) are available in various forms, including daily progestin-only pills, injectable depot medroxyprogesterone acetate (DMPA), levonorgestrel intrauterine system (IUS), and etonogestrel implant 4.
• Each of these methods has specific advantages and drawbacks, and clinicians should provide adequate and accurate information, as well as detailed counseling, to women considering using POCs 4.
• Progestin-only and nonhormonal methods, such as implants and condoms, are associated with rare serious risks, whereas estrogen-containing methods increase the risk of venous thrombosis 7.

Contraceptive Selection and Effectiveness

• Optimal contraceptive selection requires patient and clinician discussion of the patient's tolerance for risk of pregnancy, menstrual bleeding changes, other risks, and personal values and preferences 7.
• Progestin-only pills have a similar Pearl Index to combined hormonal contraceptives, with a better bleeding profile than traditional POPs, which could increase their acceptability and use 6.
• The DRSP-only pill presents a real step forward in oral contraception with only progestins, with a favorable bleeding pattern and high contraceptive effectiveness 6, 5.