Which type of birth control pill is right for you?

Dr. Srisupa Laopakorn

Obstetrics & Gynecology

     There are two types of oral contraceptives: combined oral contraceptives (estrogen and progestin) and progestogen-only pills (progestin). Combined pills are the most popular choice, while progestogen-only pills are considered for those with contraindications to estrogen, breastfeeding mothers, or for emergency contraception. Combined pills may vary in the number of tablets per pack, but most contain 21 or 28 tablets, with differences as follows:

Types of Oral Contraceptives

• 21-Day Combined Pill Pack: Every pill contains active hormones (no placebo pills). Take one pill at the same time daily until the pack is empty. Menstruation will typically start 1-3 days after stopping. Start the new pack on the 5th day of your period.
• 28-Day Combined Pill Pack: Generally contains 21 active hormonal pills and 7 inactive or "placebo" pills (some variations like 24/4 packs exist). Placebo pills are clearly distinguished by color and/or size. Take one pill daily at the same time until the pack is finished, then start the next pack immediately. Menstruation usually begins after taking 1-3 placebo pills.

Active Ingredients in Combined Oral Contraceptives

     Estrogens in combined pills can be ethinyl estradiol, mestranol, or estradiol (often as estradiol valerate). Most formulations use ethinyl estradiol. Historically, doses were high (e.g., 50 mcg), leading to significant side effects. Current formulations contain no more than 35 mcg, with some as low as 15-20 mcg. Low-dose estrogen significantly reduces side effects like nausea, bloating, and breast tenderness, though it may cause minor spotting. All types of estrogen are equally effective at preventing pregnancy at their prescribed doses.

Progestins used may include levonorgestrel, norethisterone, gestodene, desogestrel, drospirenone, nomegestrol, dienogest, or cyproterone acetate. All are equally effective in preventing pregnancy.

     Beyond contraception, these pills treat irregular periods, heavy bleeding, menstrual cramps, PCOS, endometriosis, and symptoms of excess androgen (e.g., hirsutism, acne, oily skin). They also help prevent ovarian, endometrial, and colorectal cancers.

Guidelines for Choosing Contraceptive Pills

• For Acne, Oily Skin, or Hirsutism: Recommend pills containing cyproterone acetate, drospirenone, or chlormadinone (e.g., Diane-35, Preme, Tina, Sucee, Yasmin, Yaz, Belara). For severe acne: Diane-35, Preme, Tina, or Sucee.
• For Heavy Periods or Estrogen Side Effects: (Nausea, dizziness, breast tenderness, bloating) Recommend low-dose estrogen pills like Mercilon, Meliane, or Yaz.
• For Weight Concerns & Mild Acne: Recommend Drospirenone-based pills like Yasmin, Yaz, or Synfonia.
• For PMDD (Premenstrual Dysphoric Disorder): Recommend 24/4 formulas like Yaz or Synfonia.
• Postpartum (≥ 6 weeks) & Breastfeeding: Consider progestogen-only pills.

Consistency is key for effectiveness. Importantly, contraceptive pills do not protect against STIs such as:

• HIV/AIDS, Syphilis, Hepatitis B
• HPV Infection
• They may increase the risk of thrombosis, especially in women over 35 who smoke,
• Or those with diabetes, hypertension, or high cholesterol.
• There is a slight risk of breast cancer and cervical cancer. Consultation with a doctor or pharmacist is advised before starting.

Choosing a contraceptive should involve weighing benefits and risks. Consult a physician or pharmacist for guidance.

Last Updated: 27/07/2020