Hormonal contraceptives are among the most effective options available for preventing pregnancy. The pill, patch, ring, shot, implant, and hormonal IUD methods work by using synthetic versions of the hormones progestin and estrogen to stop ovulation and thicken cervical mucus.
When used properly, combined hormonal contraceptives are 99% effective at preventing pregnancy. However, they do not defend against sexually transmitted infections.
Read on to learn how the various hormonal contraceptives work and their possible side effects.
How Hormonal Contraceptives Prevent Pregnancy
All hormonal contraceptives prevent pregnancy through one or more of the following mechanisms:
Suppressing Follicle Growth and Ovulation
In a natural menstrual cycle, a complex interplay of hormones from the brain’s pituitary gland stimulates the growth of ovarian follicles containing immature egg cells. The most mature follicle eventually ruptures to release an egg, a process called ovulation.
By keeping progesterone and estrogen levels artificially high, hormonal contraceptives suppress pituitary signals. This prevents ovarian follicles from maturing and releasing eggs.
Thickening Cervical Mucus
Progestins also thicken the mucus plug at the cervix’s opening. This creates a barrier that stops sperm from meeting and fertilizing any eggs that may be released.
Thinning the Uterine Lining
In addition, the hormones partially suppress the growth of the uterine lining (endometrium). This prevents the implantation of any fertilized eggs. However, this does not cause termination of existing pregnancies—it only stops fertilized eggs from continuing to develop.
Different Delivery Methods for Hormonal Contraceptives
While hormonal contraceptives all work through similar mechanisms, various methods deliver hormones to the body uniquely:
The Patch
The weekly contraceptive skin patch sticks onto the skin and continuously releases estrogen and progestins. These get absorbed into the bloodstream directly through the skin. A new patch must replace the old one weekly to maintain pregnancy prevention.
The Pill
A birth control pill is taken daily by mouth. The hormones get absorbed into the bloodstream through the digestive tract. Different brands contain varied mixtures and doses of synthetic estrogen and progestin. Taking a pill at the same time daily is essential for maximum effectiveness.
The Vaginal Ring
A flexible ring inserted into the vagina also steadily releases a combo of estrogen and progestin. The vaginal walls absorb the hormones so they can enter the bloodstream. The ring stays in place for three weeks and gets replaced with a new one after removal for one week to allow for a monthly period.
The Shot
The contraceptive injection contains only synthetic progestin. The shot gets administered into the arm or buttocks muscle every three months by a healthcare provider. The progestin then slowly enters the circulatory system from the injection site.
The Implant
A thin rod containing progestin gets inserted just under the skin, typically on the inner upper arm. It steadily releases hormones for up to five years. Removal and replacement require a minor office procedure.
The IUD
Intrauterine devices (IUDs) are devices that are shaped similarly to the letter T and positioned inside the uterus. Hormonal IUDs contain synthetic progestin that gets absorbed into the uterine lining. Less commonly, IUDs slowly release copper ions that are deadly to sperm and prevent fertilization.
Potential Side Effects of Hormonal Contraception
For most women, hormonal contraceptives are extremely well tolerated with few issues. However, some possible short-term side effects include:
- Headaches
- Nausea
- Breast tenderness
- Mood changes
- Spotting between periods
- Weight changes
These often resolve within three months as the body adjusts. If not, changing to a different delivery method or adjusting hormone doses can help.
There is also a small increased risk of serious issues such as blood clots or high blood pressure in some women. This tends to occur more frequently among women over age 35 who also smoke or have additional risk factors.
Because of these concerns, those with a history of issues such as liver disease, blood clots, cardiac disease, stroke, or breast cancer may not be able to use hormonal contraception safely.
Effectiveness Depends on Proper Use
When used exactly as prescribed, hormonal contraceptives effectively prevent pregnancy over 99% of the time. However, typical real-world usage lowers effectiveness since women may occasionally forget to properly take pills, replace patches or rings, or make appointments to get new shots or implants.
With the pill, a 12-hour window is allowed after a missed daily dose. But missing more than one pill per cycle or delaying the replacement of other hormonal methods by more than 24 hours eliminates protection for the remainder of that month. Additional backup contraception, such as condoms, becomes necessary in such instances.
Choosing the Right Method for You
There are many hormonal contraceptive options to suit diverse needs and preferences. The pill offers flexibility but requires strict adherence. Methods such as the IUD and implant don’t require ongoing effort after placement but need in-office removal procedures.
When weighing choices, consider your health history, tolerance for side effects, and ability to utilize different delivery mechanisms properly. Tracking menstruation may also influence decisions. Discuss all these factors with a knowledgeable gynecologist when selecting the ideal contraception for your situation.
Turn to Raleigh Gynecology & Wellness for Trusted Contraceptive Care
The Raleigh Gynecology & Wellness team has extensive experience helping women select appropriate, effective, and well-tolerated contraception. We take time to understand medical history, lifestyles, reproductive goals, and preferences to offer customized recommendations.
For expert guidance identifying the ideal hormonal or non-hormonal contraception for your needs, contact us today at (919) 636-6670 or online to schedule a consultation. Our team looks forward to helping you make informed, empowered contraceptive choices for health and well-being.