UK Warns Implanon Contraceptive May Not Protect Against Pregnancy


The Medicines and Healthcare Products Regulatory Agency (MHRA) is warning British women about the long-term contraceptive implant called Implanon. Due to an error during implantation, hundreds of women have reported unwanted pregnancies.

Implanon is a hormone-filled matchstick-sized tube that is inserted under the skin on the inside of the upper arm. If administered properly, the synthetic progesterone it contains (called etonogestrel) protects against pregnancy for three years.

Etonogestrel works by tricking the body into thinking that ovulation has already occurred, preventing the release of eggs from the ovaries. It also affects the natural mucus of the cervix, making it difficult for sperm to cross over into the uterus to fertilize eggs that may inadvertently be released.

Read: Three Contraceptive Implants Prevent Pregnancy Equally Well

Implanon was first approved in the UK in 1999 and was approved in the US by the FDA in July 2006. About 1.4 million women have used Implanon during the past 12 years.


The MHRA reports that 584 women have reported unwanted pregnancies after implantation of the contraceptive and 1607 women in total have complained about the device.

The error occurred when the plastic tube that contains the hormone was implanted too deeply or became dislodged in some cases. If administered properly, the manufacturer states, it is more than 99% effective, same as the oral birth control pill.

Read: 5-Day Emergency Contraceptive Named Ella

Implanon has since been replaced by Nexplanon, which has a pre-loaded applicator for easier insertion. However, the original has not been removed from the market and it will continue to be offered until the product is sold out.

The Department of Health stresses that the vast majority of women will be protected from pregnancy while using Implanon, but if a woman is concerned, she should talk to the physician who placed the device or can call the FPA helpline at 0845 122 8690.

In the US, women who experience negative effects while on any prescription drug should contact the FDA’s MedWatch program through the website or call 1-800-FDA-1088.



well i have been on the implant since october and i have had shpcking pains in my arm where the implant is and recently iv got a pregnant belly pregnancy symptoms and iv taken pregnancy test n it says negative but in side i feel something in me or happening and i think it is not working