| Implanon Implanon
is a relatively new contraceptive technology that is injected underneath the skin
of the upper arm by a health care provider in her or his office, much like Norplant
(which is now no longer available in the United States), but with only one rod.
The Implanon rod slowly releases a progestogenic hormone called etonogestrel over
the course of three years. | 
Implanon device |
| Implanon
is inserted relatively painlessly into the underside of the upper arm after local
anesthetic is used to numb the area. A health care provider will use a special
applicator to insert the rod underneath the skin, taking about one minute. A woman
won't be able to see the rod (unless she is very thin), but she can feel it with
her fingers. Tissue forms around it after insertion to make sure that it doesn't
move. Some women may experience slight swelling after insertion, but other problems
are rare.
The
rod itself is 40 mm in length and 2 mm in diameter (about 1.5 inches by 0.08 inches),
and is made of a biodegradable synthetic material that is commonly used in artificial
joints. Implanon can be inserted at any time, but health care providers recommend
having it inserted between the first and fifth day of menses or, if she is on
the pill, the day after she takes the last pill for the month. If Implanon is
inserted at any other time, it is recommended that a woman use other contraception
for the first 7 days. The
Implanon rod contains 68 milligrams of etonogestrel that is released over the
three-year period. About 60 - 70 micrograms (µg) per day are released in the first
year and the amount decreases over time until only about 25 - 0 µg per day are
released in the third year. After the third year, Implanon will continue to release
some hormone, but it will be at ineffective low levels. The etonogestrel thickens
cervical mucus, which in turn prevents sperm from fertilizing an egg and from
allowing any egg that does happen to get fertilized from implanting itself in
the uterine wall. Implanon also completely inhibits the release of eggs from the
ovaries during the first two years, and continues to do so during the third year,
but less effectively. |
|
While
using Implanon, most health care providers need to see users for regular 6-month
checkups. During clinical trials, about 30 percent of the women in Europe and
Canada discontinued use within 2 years, primarily due to complaints about irregular
bleeding. This number is not significantly different from discontinuation rates
for Norplant.
The
removal of the rod takes slightly longer than the insertion - about two minutes
- but with the use of local anesthetic, most women describe "mild discomfort."
A health care provider makes a tiny incision in the skin near the tip of the rod
and then pulls the rod out from underneath the skin. Within several days of removal,
etonogestrel will no longer be in the blood stream, and fertility returns to its
pre-Implanon state within one month. A small scar (2 mm) may remain where the
rod was removed. In
studies of over 2,000 women for three years, not one who used Implanon became
pregnant. The makers of Implanon do warn, however, that no method of contraception
can be 100 percent effective. Like
other forms of hormonal contraception, Implanon has side effects. According to
a review of Implanon published in The Annals of Pharmacotherapy in 2001, about
47 percent of women reported at least one side effect during the three years.
Irregular (or missing) periods, weight gain, acne, headaches, or breast tenderness
each occurred in about 5 percent of Implanon users. Another 2.5 percent of users
experienced hair loss, changes in mood and/or libido, abdominal pain, or painful
periods. Another known side effect is an increase in blood pressure, which is
why it's important to have regular follow-up appointments with your health care
provider. |
