Oregon State University

Hormonal Methods

Hormonal methods of contraception protect against unwanted pregnancy, but not sexually transmitted infections (STIs). Here is information on each form of hormonal contraception.

The Pill (Oral Contraceptives; Birth Control Pills)

  • Combined effects of synthetic hormones called estrogen and progestin.
  • Estrogen decreases production of the hormone that helps develop the ova within the ovaries.
  • Progestin prevents the proper growth of the uterine lining and thickens the cervical mucus forming a barrier against sperm.
  • Pills can be progestin only or a combination of estrogen and progestin.

The Shot (Depo-Provera)

  • Injectable progesterone that lasts for three months and prevents ovulation.

The Patch (Ortho Evera)

  • Worn for a week at a time for three weeks, then no patch for three weeks.
  • Can be worn on the buttocks, abdomen, upper torso or upper arm.

The Ring (NuvaRing)

  • Inserted into the vagina and left in place for three weeks.

Emergency Contraception

  • Combination progestin and estrogen or just progestin; but it’s concentrated enough to interrupt a women’s normal hormonal patterns and prevent pregnancy after unprotected intercourse has already occurred.
  • Works better if taken right away, but can be taken for up to five days after unprotected sex.
  • Progestin only pill (Plan B) reduces risk of pregnancy by 89 percent.
  • Combined pills reduce the chances by 75 percent.
  • Is available over the counter at the SHS Pharmacy.