What is a Birth Control Implant?

A birth control implant is a small thin rod that is inserted under the skin on the inside of the upper arm and releases hormone gradually into the body. This hormone, Progestin or Progestogen, prevents pregnancy or contraception.

The birth control or contraceptive implant gives protection from pregnancy for a period of about four years. It is a type of long-acting reversible contraceptive like an intrauterine.

The doctor or nurse injects an anesthetic to make a small patch of the arm numb. Then, they use a special inserter tool to slide the implant under the skin. It is the most convenient and effective method to control pregnancy.

The birth control implant is prescribed as Nexplanon, in the United States. It was earlier sold in Australia, as Implanon, which contained Etonogestrel, a progesterone-like hormone.

How Does an Implant Prevent Pregnancy?

The implant releases the hormone “Progestin”, which prevents pregnancy in two ways:

  • Progestin thickens the mucus in the cervix which prevents the sperms from swimming to the egg. Thus, the sperm and egg do not get fertilized.
  • Progestin prevents the eggs from leaving the ovaries and thus, there is no egg to fertilize.
How Does the Implant Prevent Pregnancy?

What are the Benefits of Birth Control Implants?

  • The implant is convenient and confidential - It is concealed under the skin
  • The birth control implants or chips are long acting - they last for 3 to 5 years - Implants make the periods better - Nexplanon reduces period cramps and makes the period lighter
  • Implants are “insert and forget” type of contraceptives - Once implanted, there is no need think about contraception every day
  • Implants have only one hormone, Progestin - The other birth control methods have two hormones, Estrogen and Progestin. Estrogen is not tolerated by many people; hence, Nexplanon becomes the preferred choice when Estrogen has to be avoided as a medication
  • Nexplanon is not permanent- it is reversible - The implant does not affect fertility and the woman can become pregnant as soon as the implant is removed
  • Implants work better than birth control patches, pills or vaginal rings
  • Implants do not interfere with sexual intercourse

What are the Disadvantages of Birth Control Implant?

The disadvantages of birth control implant include:

  • Irregular or longer than usual periods could occur in the first 6 months
  • Insertion and removal has to be done with a minor procedure
  • No protection against sexually transmitted diseases
  • Slight bruising or pain when first inserted into the arm; there is a small risk of infection

The doctor must be consulted if any of the following symptoms are noted:

  • Pus, redness or bleeding in the arm where the implant was inserted
  • Irregular or heavy bleeding from vagina
  • Implant seems to have shifted position
  • Yellowing of skin or eyes

How Effective is a Birth Control Implant?

The implant is very effective in protecting from pregnancy all day, for up to four years. It is not permanent, hence, if one wants to get pregnant, the doctor or nurse can remove the implant from the woman and she can become pregnant.

The implant is about 99% effective in controlling pregnancy. Statistical reports indicate that 1 in 20 women may still get pregnant, in spite of having implants.

However, the effectiveness of an implant can be reduced by certain medications:

  • TB medicine
  • HIV medicine
  • Mental disorder medicine
  • Antiseizure medicine
  • Herbal medicine like St. John’s Wort
How Effective is a Birth Control Implant?

What are the Side Effects of Birth Control Implant?

Side effects with the arm implants are rare. Some side effects which could occur include:

  • Breast pain or tenderness
  • Headaches
  • Weight gain
  • Nausea
  • Infection where implant was inserted
  • Ovarian cysts
  • Mood changes
  • Pain or bruise around the area where implant was inserted
Probable Side Effects of Birth Control Implant

How long does it take for the Birth Control Implant to work?

If an implant is inserted during the first five days of the period, the woman is protected from pregnancy immediately.

However, if the implant is inserted at any other time of the menstrual cycle, some other form of birth control, e.g. female condom, will have to be used during the first week. After that week, the implant starts working and the woman is protected from pregnancy, for a period of about 4 years.


  1. Birth Control Implant - (https://www.plannedparenthood.org/learn/birth-control/birth-control-implant-implanon)
  2. Contraceptive implant - (http://www.familyplanning.org.nz/advice/contraception/contraceptive-implant)
  3. Contraceptive implants - How does it work? - (https://www.thewomens.org.au/health-information/contraception/contraceptive-implants)
  4. What is the Birth Control Implant? - (http://teensource.org/birth-control/implant)
  5. What are the disadvantages of birth control implants? - (https://www.plannedparenthood.org/learn/birth-control/birth-control-implant-implanon/what-are-the-disadvantages-of-birth-control-implants)
  6. Implant - (https://www.bedsider.org/methods/implant)
  7. Etonogestrel (Implanon), Another Treatment Option for Contraception - (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2683610/)
  8. Nerve injuries related to etonogestrel implant - (https://www.contraceptionjournal.org/article/S0010-7824(12)00955-9/fulltext)

Latest Publications and Research on Birth Control Implant

Do you wish to consult Obstetricians and Gynaecologists (OB/GYN) for your problem? Ask your question

Most Popular on Medindia