Many types of oral birth control or implanted birth control devices are a combination of estrogen and progesterone, or progestin. Others come in progestin-only formulations and it’s possible to derive information about progestin side effects from these. Like all medications, progestin, which is a synthetic substitute for the hormone progesterone, does have side effects and these may affect people to greater or lesser degree. A few people will notice no change, some will have changes for a while that will gradually lessen or become tolerable, and others may find there are too many side effects to continue taking the medication.
There are a number of very common progestin side effects. Many women note sore breasts when they take this medicine, and some people have problems with bloating or may even gain a small amount of weight. These side effects are similar to those encountered the week or so prior to getting a menstrual period. This makes sense, given that progesterone is released in the second half of the menstrual cycle and helps to stimulate menstruation.
Other effects explained by this relationship are headaches or the occasional breakthrough bleeding. On the other hand, periods may be lighter and this medication is sometimes prescribed to treat heavy periods. Most women will still continue to menstruate for at least a couple of days each month.
Progestin side effects may also include moodiness, and for some women, this can become more serious and turn into pronounced depression. Someone who is feeling very blue, begins to feel hopeless or suicidal should talk to their doctor right away, as this medication may be inappropriate. Some people also experience very pronounced nausea when they take progestin, which may cease or worsen. Nausea may come with dizziness that is transient or long lasting.
There are additional progestin side effects that may not occur immediately or at all. Some women develop darker patches on the skin, especially the face. Others experience greater vaginal discharge, lower interest in sexual activity, tendency toward anxiety, more or less skin breakouts, very long periods, or increased appetite. More serious is the tendency certain forms of progestin-treatments have to result in bone loss. This has been shown to be a problem with Depo-Provera® shots, and these are especially discouraged for use with teen girls who are still developing.
Some contraindications exist with progestin side effects. The medication is not suitable to those with cancer of the breasts or reproductive tract, in pregnant women, or in those with a history of stroke. Those with liver disease may be have different treatments instead. Though rare, some people can have anaphylactic allergic reactions to progestin, and any sudden difficulty breathing, hives, or swelling of the face is a medical emergency. Some medications may not work with this medication either, including many of the anticonvulsant or mood stabilizer drugs, which could render progestin ineffective as birth control.
