The options for contraception today seem to be plentiful, but they really fall into two categories: barrier methods and hormonal methods. And, of course, there is abstinence, but that one is self-explanatory!

Barrier methods include the diaphragm and condoms. Diaphragms are typically made of silicone or latex, and they must be fitted by a doctor. To use it, you pinch the diaphragm edge and insert it into the vagina until you reach the cervix. Then it opens into place, and you can adjust it with your finger. Typically, you add some spermicide to the inside of the diaphragm before inserting it to kill any sperm that manage to swim around it. The diaphragm can last for years if properly washed and dried after use. Because it’s completely reversible, and it does not involve any hormones, some women really like it. On the other hand, it is only about 84% effective in pregnancy prevention, and it must be left in place for 6 hours after intercourse. If it is not fitted properly, it can be uncomfortable.

Condoms are the over-the-counter barrier method. They are readily available, inexpensive, and offer lots of varieties. They are typically latex, although there are other materials, such as animal skin, for those who are allergic to latex. However, STDs can penetrate the animal skin, so in that case, it is often recommended that a man first put on an animal skin condom and cover that with a latex condom (or the other way around if the woman is the one with the latex allergy). Efficacy of condoms is estimated at 85%, and use with a spermicide is recommended to improve birth control. They do have expiration dates, and they can easily break. And, of course, they are not reusable. For STD prevention, properly used, condoms are the only method that offers any protection.

Hormonal methods include oral contraceptives (“the pill” or OCs), intrauterine devices (IUDs), vaginal rings, patches, and injectable contraceptives. Let’s start with OCs.

OCs all function in the same way—they override your natural hormonal cycle. In this way, they inhibit ovulation and decrease the thickness of the uterine lining to prevent implantation. Because the doses of hormones today are so low, for some women, even missing one dose can lead to pregnancy. The manufacturers will say that efficacy is 99%, and it is if you take it at exactly the same time every day and never miss a dose. With regular use and some variability in time of dose, the efficacy is probably more like 92%. There are estrogen/progestin combination pills and progestin-only pills. Side effects of the estrogen/progestin products include blood clots (especially if you’re over 35 and a smoker), headaches, breast tenderness, nausea, and depression. For the progestin-only products, the major side effect is irregular menstruation and spotting. That usually disappears after a few months. All of the hormonal methods require a prescription from a doctor and an annual exam, which adds to the cost.

Vaginal rings are relatively new. Like a diaphragm, it is inserted in the vagina as high as possible, but unlike the diaphragm, you leave it in place for 3 weeks. It releases estrogen and progestin to prevent pregnancy. Efficacy is around 92%.

Patches are just another way to deliver the estrogen/progestin dose. They are worn for a week, then removed and replaced with a new patch. The efficacy is the same as OCs.

The only injectable contraceptive available in the US is progestin-only. It is a shot that is given every 3 months. It is highly effective, around 97%, and it avoids the side effects of estrogens.

IUDs can be either hormone-free or hormonal. If it’s a hormone-free type, then it works by constantly irritating the lining of the uterus to prevent implantation. The hormonal version does that, too, plus it secretes constant progestin. These both have very high efficacy rates, over 97%. They are left in for years, and in that sense, they can be quite cost-effective. There is a risk of pelvic infection after placement, and if pregnancy occurs, it can be complicated. They must be placed and removed by a doctor. Generally, they are best for women in monogamous relationships who do not plan to be pregnant for at least 5 years.

When deciding which method is best for you, think about cost, your relationship status, reversibility, side effects, and whether or not you can accept an unplanned pregnancy. If you’re over 40 and do not plan to have any more children, perhaps consider a tubal ligation instead (or a vasectomy for your partner!). That way you can avoid any risks of hormones and accidental pregnancy. Most doctors hesitate to do a tubal ligation on younger women unless they have several children already because reversals may not restore fertility. And don’t wait around for the male contraceptive pill—that is still very far off in the future.