Birth Control Implants: Working, Effectiveness, Benefits, Side-Effects


Among the many contraception options available today, birth control implants are one of the highest-ranking in terms of efficacy. This device is as small as a matchstick and made of plastic. It works by releasing certain hormones in the body to prevent conception.

Also known as “contraceptive implants”, these implants are a form of long-acting reversible contraception (LARC) like intrauterine devices (IUDs). Once inserted, you can forget about them for a while.

Though they protect against unwanted pregnancies, they cannot protect against sexually transmitted diseases.
Flexible and small, the implants fit under the skin of the woman’s arm and are easily removable as well. Only a trained healthcare professional is to perform the insertion or removal of the device.

Nexplanon is the commonly known brand name in the U.S. for these implants. In this article, we discuss everything about birth control implants, from their working, effectiveness, benefits, and side-effects.

Working of Birth Control Implants

Birth control implants release small amounts of progestin into the woman’s bloodstream. Progestin is a synthetic form of the naturally occurring sex hormone, progesterone.

The rod contains 68 mg of etonogestrel (progestin medication). This is released constantly at a rate of 60 to 70 micrograms during the first year of insertion. The rate steadily falls to 25 micrograms a day by the third year.

Progestin primarily works to prevent pregnancies in three ways:

● Inhibiting Ovulation

Ovulation is the process where the ovaries release eggs during the monthly cycle for fertilization. Ultimately, there are no eggs to fertilize due to the inhibition of ovulation.

● Thickening the Cervical Mucus

The cervix produces a white (or clear) sticky fluid called mucus. Its characteristics change throughout the month. Progestins cause this cervical mucus to become especially thick.

This thickened mucus ultimately blocks the passage which the sperm uses to reach the eggs. Thus, even if ovulation does occur, the sperm will not be able to reach the egg for fertilizing it.

● Shrinking the Thickness of the Endometrium

The Endometrium is the lining inside the uterus that provides a fertilized egg with all the nourishment it requires to grow. Progesterone is responsible for maintaining its thickness.

However, progestin makes the endometrium thinner. This prevents the fertilized egg (if any) from getting implanted into the lining, thus inhibiting its growth.

This way, birth control implants function to prevent pregnancies pre-ovulation, post-ovulation, as well as post-fertilization.

The birth control implants will start working immediately if it was inserted:

  • Within the first five days of your menstrual cycle
  • Instantly after the last active pill of a pack of regularly taken oral contraceptives

You might have to consider relying on other methods of contraception if the implant was inserted in any other frame of time.


An efficacy rate of 99 percent easily makes birth control implants one of the most effective contraceptives available in the market today.

According to the Centers for Disease Control and Prevention (CDC), implants have a failure rate of less than 0.1 percent. This indicates that less than 1 woman out of 100 faces an accidental pregnancy every year by using implants as their sole contraceptive.

The durability of implants, which is anywhere between 3 to 5 years, makes it this efficient. It can be inserted in the arm and forgotten about for the time being. Thus, there is no room for mistakes.

In case you feel like getting it removed for any reason, it is easily removable. Once it is removed, your fertility will return quickly as well (approximately within 21 days).

Sexually transmitted diseases (STDs) are the only thing birth control implants are not effective in terms of protection. Condoms are the only contraceptives that can safeguard against STDs effectively.


Birth control implants have many notable benefits. These are:

  • 99 percent efficiency
  • Affordable and cheap as compared to other long term contraceptive methods
  • Efficient for up to 3 years after insertion (depending on the brand)
  • Easily removable
  • Does not affect future pregnancies
  • Can be utilized by women who cannot use estrogen-based contraceptives
  • No need to remember it every time you have sex
  • Safe to use while breastfeeding
  • Helps with heavy bleeding and painful periods
  • Can sometimes cause the complete absence of periods, which is beneficial for many women
  • Can resume the ability to get pregnant within 21 days of removal
  • Might cause an improvement in acne
  • Slight safety against endometrial cancers

These implants can also reduce the risk of pelvic inflammatory disease. The thickening of cervical mucus caused due to them inhibits the upward movement of microbes from the vagina to the uterus.


Birth control implants can have certain negative side-effects as well. These can vary in terms of severity and frequency as per the personal circumstances of the user. Some of the most common side-effects include:

  • Acne
  • Mastalgia (breast pain)
  • Breast soreness and tenderness
  • Nausea
  • Headache
  • Weight gain
  • Vaginal dryness
  • Abdominal pain
  • Scarring
  • Pain or infection (around the area where it is inserted)
  • Dizziness
  • Ovarian cysts (noncancerous)

Many women also reported a disturbing menstruation cycle. This is one of the most common side-effects and also the reason why over 10 percent of women discontinue using the implant. These changes show themselves within three months of insertion and can indicate the future course of menstruation patterns for the user. Changes include:

  • Absence of bleeding
  • Irregular bleeding
  • Heavy or light bleeding
  • Constant bleeding for over 2 weeks in a row
  • Recurrent bleeding episodes (over 5 in 90 days)

Severe Side-Effects of Birth Control Implants

The adverse effects on the more severe side of the scale only occur on rare occasions. However, they are not impossible so it is best to be fully aware of them. Some of them include:

● Complications Due to Improper Insertion

If the implant is inserted too deep in the arm it can migrate to other parts of the arm or even the pulmonary artery. In this case, the individual might need to go through deep surgery or endovascular removal.

The rod can also break during insertion or removal. This breakage can lead to a higher amount of progestin released in the body, causing unwanted complications.

● Hypertension

If you have a history of hypertension, the doctor might ask you to avoid implants. Progestin-only contraceptives might be safe. This is especially the case for patients who have their hypertension under control.

In case the implants are causing frequent fluctuations in your blood pressure, immediately get them removed.

● Ectopic Pregnancies

An ectopic pregnancy occurs outside the womb (uterus). In this case, the egg usually implants itself in one of the fallopian tubes. It can occur with the implant inserted inside the body. Though this is an especially rare side-effect, it is not impossible.

● Others

Some other severe side effects are:

  • Breast cancer
  • Psychological and nervous system disorders
  • Fluid retention
  • Gallbladder issues
  • A Vaginal infection (Vaginitis)

This is not a complete list of all the possible complications and side-effects. Consult a doctor for a better idea of the same.

Birth Control Implants : Wrapping Up

Only a trained medical professional should perform the insertion and removal of a birth control implant. Avoid using an implant in case you have unexplained vaginal bleeding or a history of blood clots. Inform your doctor about your entire medical history in detail to ensure the utmost safety.

It is important to consult a medical health professional and discuss all the possible risks and side-effects before making any decisions. If any of the symptoms persist and refuse to subside, contact a doctor immediately.