What is the Problem?
All progestin contraceptives are known to increase a woman’s risk of a blood clot, but Implanon has been associated with a 40% increased risk of blood clots. A blood clot from Implanon can cause severe side effects, including heart attack, cardiac event pulmonary embolism, hospitalization, or death.
What is Implanon?
Implanon is a birth control implant. It is about the size of a matchstick, and it is implanted just beneath the skin on a woman’s upper arm. It reduces the risk of pregnancy by slowly releasing small amounts of the hormone etonogestrel, which is a synthetic version of the female reproductive hormone progestin.
How Does Implanon Work?
Implanon reduces the risk of pregnancy by making several changes to a woman’s reproductive system. It inhibits the ovaries from releasing an egg. It also increases the amount of cervical mucous, which makes it more difficult for sperm to enter the uterus. Implanon is more than 99% effective at preventing pregnancy for about three years.
How Many Women Have Used Implanon?
Implanon is made by Organon International, and it was approved by the Food and Drug Administration (FDA) in 2006 in the U.S. Implanon has been used internationally since 1998. Worldwide, more than 2.5 million women have used Implanon to reduce the risk of pregnancy. The updated version of Implanon is Nexplanon.
Studies of Health Risks From Implanon
A Danish study was published in the British Medical Journal in May 2012 which found that most non-oral hormonal contraceptives are associated with an increased risk of blood clots. Women who use Implanon (a subcutaneous implant) were found to have a 40% increased risk of blood clots compared to women who did not use hormonal contraceptives.
The study included data on Danish women who were not pregnant, had no medical history of cancer or blood clots, between the ages of 15-49, who used the contraceptive at some point between 2001 and 2010. During this time period, the researchers found that the only non-oral contraceptive that was not linked to a higher risk of blood clots was a uterine implant (IUD).
Implanon and Blood Clots
Blood clots from Implanon tend to develop deep inside the lower legs, in a condition called Deep Vein Thrombosis (DVT). These blood clots can grow very large, causing severe damage to the veins inside the legs. The clots can also break loose from their original location, flow to the heart, and be pumped into the lungs (causing a pulmonary embolism).
Blood clots may also form in arteries, where they could travel to a major internal organ such as the heart or brain, causing a stroke, cardiac event, or heart attack.
What is the Risk?
Blood clots are a very serious side effects of Implanon because they can lead to death. All women who take Implanon are at risk. However, some women have an even higher risk — those who smoke, are over 35 years old, or have a medical history of blood clots or cardiovascular disorders.
Implanon Side Effects
- Blood clots
- Pulmonary embolism
- Heart attack
- Cardiac events