Many women interested in hormonal birth control consider using the contraceptive implant. This device, sold under the brand name Implanon, goes under the skin of the upper arm and releases the hormone progestin. This thickens cervical mucus, thins the lining of the uterus and inhibits ovulation to prevent pregnancy for up to three years. Although this method has a less than 1 percent failure rate and is quite effective at preventing pregnancy, it has disadvantages as well.
Insertion and Removal
Women must go to a trained provider for the insertion and removal of the contraceptive implant. Although the insertion and removal process is generally not painful, it can be uncomfortable for some women. The Physicians' Desktop Reference also notes that if a doctor does not insert the implant properly, it may be difficult or impossible to remove it, and it may not prevent pregnancy.
Spotting or Frequent Irregular Bleeding
The Association of Reproductive Health Professional, or ARHP, notes that 50 percent of women experienced unpredictable spotting during the first six months of use in clinical studies, but only 30 percent of women experienced spotting after this time. Less than 10 percent of women experienced frequent irregular bleeding while using the contraceptive implant.
Amenorrhea
Amenorrhea is the complete absence of menstruation. This occurred in 20 percent of women during clinical trials, according to the ARHP. Although some women enjoy not menstruating, others find it disconcerting and may worry they may be pregnant when they are not.
Prolonged Bleeding
While some women stop menstruating completely while using the contraceptive implant, others find their menstrual bleeding to become heavier or last longer. This prolonged bleeding occurred in 20 percent of women during the first three months in clinical trials, explains the ARHP, but declined to only 10 percent of women after the first three months.
Risks
Like other forms of hormonal birth control, serious complications could occur from using the contraceptive implant. MayoClinic.com notes that risks associated with Implanon include an increased risks of ovarian cysts and blood clots, mood swings, depression, headaches, weight gain, acne, nausea, dizziness, abdominal or back pain, decreased sex drive, mild insulin resistance, hair loss, sore breasts, vaginal inflammation or dryness and viral infections. Women who take the contraceptive implant also have a higher risk of an ectopic pregnancy if the implant fails and conception occurs.
No Protection Against STIs
Although it effectively protects against pregnancy, the contraceptive implant does not offer protection against sexually transmitted infections, or STIs. Women who are not in monogamous relationships need to use another form of birth control for STI protection in addition to using the contraceptive implant.
