There are many options for birth control
, both in terms of estrogen dosage and mode of use (pill, ring, patch, intrauterine device, to name some). Your primary care doctor
or obstetrician/gynecologist can provide more counseling about the most appropriate type of contraceptive for you. You should also be sure to ask about getting a Pap smear before you start using birth control; the frequency of Paps will depend on your age and any history of abnormal Paps or new sexual partners.
Several brands of the pill have very low estrogen content, 20 micrograms per pill; other brands have 35 and 50 micrograms of estrogen. Each of these dosages are equally effective for preventing pregnancy. The difference is in terms of side effects. Low-dose estrogen pills are more likely to result in breakthrough bleeding
(e.g. vaginal bleeding between periods). The low-dose brands include: Loestrin 1/20, Junel 21 1/20, Alesse, Lessina, Yaz, Mircette, Kariva, Ortho Tri-Cyclen Lo (this has 25 micrograms). There is little difference in these brands other than that some are monophasic (same amount of progesterone in each pill) which others are biphasic or triphasic (progesterone content differs each week of the cycle).
The vaginal ring (NuvaRing) delivers 15 micrograms of estrogen per day, making it even lower-dose than the low-dose pill. The circulating levels of estrogens are lower than with the pill. The ring stays in place for 3 weeks and then is removed for 1 week during menstruation. The intrauterine devices (Mirena or copper IUD) do not contain any estrogen; Mirena contains only progestin. These are associated with irregular periods for the first year of use, after which many women stop having a period, and remain in place for up to 5 years (the copper IUD can stay in longer). The IUD has the highest efficacy as birth control since the patient does not need to remember to "do" anything. The patch has been associated with higher levels of circulating estrogen, and is less effective in women that weight over 200 lbs.
There are several other forms of progesterone-only contraceptives, including the "mini pill" and DepoProvera injection. Both of these can cause irregular periods at first. The mini-pill must be taken at the exact same time every day to be effective; DepoProvera lasts for 3 months and is associated with weight gain. You can discuss all of these options with your doctor prior to making your choice.
Please note that certain medication interactions can make birth control less effective, particularly certain antibiotics and anti-seizure medications. You should discuss your other medications with your doctor.