Side Effects of Birth Control Pills
A few common side effects of birth control pills include nausea, spotting between periods, and headache. Several factors play a role in determining which side effects are likely (or unlikely) to occur, including the strength of the estrogen, the type of progestin, and the dose of progestin. Certain birth control pill side effects are more serious and require immediate medical attention, such as depression, pain in the calf, and migraines.
As with any medicine, side effects are possible with birth control pills (oral contraceptives); however, not everyone who uses birth control pills will experience side effects. In fact, most women tolerate them quite well. If side effects do occur, in most cases, they are minor and either require no treatment or can easily be treated by you or your healthcare provider. Some types of birth control pills may be more or less likely to cause certain side effects than others.
(This article covers many, but not all, of the possible side effects with birth control pills. Your healthcare provider can discuss a more complete list of birth control pill side effects with you.)
In clinical studies for most medications, one group of people is given the actual medication, while another group is given a placebo (a "sugar pill" with no active ingredients). The side effects in both groups are carefully documented and compared. This way, it is possible to see what side effects occur, how often they appear, and how they compare to the group not taking the medicine. However, it is not possible to use a placebo in clinical trials for birth control pills, as this would lead to many unintentional pregnancies.
It is difficult to obtain much information about side effects from studies that do not use a placebo. Because there is no way of knowing if any particular problem is actually a side effect of the medication, only vague information is available about side effects of birth control pills. The prescribing information for all birth control pills simply lists side effects seen with birth control pills in general, instead of side effects for a specific product. Specific side effect information, such as how frequently they occur, is not provided.
Based on information available, some of the common birth control pill side effects include but are not limited to:
- Acne, although birth control pills can also improve acne (see Birth Control Pills and Acne)
- Breast tenderness and enlargement
- Breakthrough bleeding and spotting between periods
- Nausea and vomiting
- Changes in your eyes that make it more difficult to wear contact lenses
- Changes in sex drive (typically a decrease).
Women are often concerned about weight gain due to birth control pills, but recent research suggests that birth control pills do not cause weight gain for most women (see Birth Control Pills and Weight Gain).