Birth Control Pills

The birth control pill, the little white tablet that helped spawn the sexual revolution of the 1960s, is nearly 40 years old. And it's looking better than ever. In years past, women had many concerns about potential side effects of "the pill," but today, new formulations as well as long-term health studies have put most of those fears to rest. This is not your mother's birth control pill.

How the pill works is pretty much the same as ever: with daily doses of the hormones estrogen and progestin, it overrides a woman's monthly hormonal fluctuations, preventing ovulation. It also thickens cervical mucus, cutting sperm off at the pass, so to speak, and makes the uterus less hospitable to an egg. Used correctly, birth control pills have always been about 99 percent effective.

Still, there are differences between today's birth control pills and the original. For starters, there is more than one type of pill; indeed, over 30 brands are currently available. What generally distinguishes one from another are their hormonal formulations. It's important to understand the different types of formulations available and to discuss the options with your doctor.

Key Features of Birth Control Pills

Most birth control pills are "combination" pills, formulated with both estrogen and progestin. A progestin-only pill, known as a "mini-pill," is prescribed primarily for women who can't take estrogen.

Unlike the original pill, which packed as much as 150 micrograms of estrogen, today's low-dose versions typically use 30 to 35 micrograms. Some even go as low as 20. Progestin levels have also dropped significantly. The result is a lessening of the annoying side effects—moodiness, bloating, nausea—that once led women to toss pill packs on the trash heap.

Lower hormone levels have also improved the safety profile of birth control pills. Concerns about possible pill-related health problems—ranging from breast cancer to heart disease—have been virtually laid to rest thanks to a series of scientific studies conducted over the past several decades. One such study found that a woman's risk for breast cancer ten years after going off the pill was no greater than the risk for a woman who had never taken the pill.

How to Use Birth Control Pills

While all of today's formulations are considered safe, experts still say it's best to start with the lowest hormone dose possible. Then, if side effects occur—and persist beyond an initial adjustment period—your doctor may prescribe another formulation, depending on what side effects you experience.

Either estrogen or progestin may cause side effects. In the case of estrogen, nausea, breast tenderness, fluid retention, and headaches are usually due to too high a dose, while breakthrough bleeding means too low a dose. If side effects don't subside after a few cycles, an adjustment of estrogen levels up or down should eliminate them. Two chemical varieties of estrogen are used—ethinyl estradiol and mestranol—but there should be no difference in their side effects.