What is a contraceptive implant? And how does it work?
A contraceptive implant is a small, flexible, plastic rod roughly 4cm long that is placed under the skin of the upper arm (subdermal implant). It’s known as a long-acting reversible contraceptive (LARC), which lasts for years, and can be forgotten about once fitted.
Once installed, the contraceptive implant releases small amounts of the progestogen hormone, which prevents ovulation, and thickens the mucus in the cervix to prevent sperm from entering the uterus. This double-effect makes the contraceptive implant 99.95% effective.
How is the contraceptive implant fitted?
The implant is injected under the skin of your inner upper arm by a doctor or nurse, with anaesthetic used to prevent pain. If you would like to stop using the contraceptive implant, or have finished its three year lifespan, a doctor or nurse would also need to remove it.
What are the pros and cons of contraceptive implants?
- Incredibly cheap. Implanon costs around $40 for three years for Medicare recipients1
- Lasts for up to three years
- You don’t have to remember to take a daily pill, or to renew your prescription
- Doesn’t risk making sexual intercourse less pleasurable
- Safe for most women
- It can make periods lighter and less painful, and ease symptoms of premenstrual syndrome
- It can reduce symptoms of acne
- There’s no protection from STIs
- It will change your monthly period. Many women have no bleeding at all, but some have longer, heavier, or more frequent periods.
- As a hormone, it can cause side effects such as:
- Changes in mood
- Nausea or bloating
- Tender breasts
- Lowered sex drive
- You may experience side effects such as headaches, mood changes, and tender breasts.
- It can cause slight bruising when being inserted and removed.
Common birth control implants
In Australia, the term “contraceptive implant” is typically reserved for a single product: Implanon, the device described above. But there’s another type of contraceptive implant that can be recommended by your doctor—Mirena, a hormonal IUD that is inserted into the uterus (known as an intrauterine system).
Implanon vs Mirena
Implanon is a small plastic rod that is inserted into the skin of the upper arm, while Mirena is a t-shaped plastic frame that is inserted into the uterus. With Mirena, the nurse or doctor will use a tool to insert the device through the opening of your cervix, which can be briefly painful.
Implanon uses etonogestrel as its hormone, and Mirena uses levonorgestrel, which are both from the progestogen chemical family, and provide similar birth control results. Mirena is designed to last for two years longer than Implanon, with a five-year lifespan.
Mirena is also offered as treatment for heavy menstrual bleeding (menorrhagia), whereas Implanon is purely a contraceptive treatment.
Mirena requires an STI test before being fitted, as STIs can cause pelvic inflammatory disease—a serious infection. For both devices, you will be tested for pregnancy.
Implanon works immediately if you have it fitted within the first five days of your period. Otherwise, it will start to work after seven days. Mirena are reversible, which means you can get pregnant immediately after they’re removed.
Implanon and Mirena are very similar contraception options, both highly effective, and good contraceptive solutions.
- Contraceptive implant, Get The Facts