A small amount of the hormone progestin is released through the capsules continuously, more during the first year and a half, but then at a level similar to most contraceptive pills afterward.
After three months of using, women may need to schedule a follow-up appointment to monitor blood pressure and discuss any concerns.
Common side effects include weight gain, nervousness, anxiety, nausea, vomiting, mastalgia, dizziness, dermatitis/rash, hirsutism, scalp-hair loss, headache, depression, and acne.
It was developed by Sheldon J. Segal and Horacio Croxatto at the Population Council beginning in 1966, with the first clinical trial in Chile in 1974.
[19] The original (six capsule) Norplant was approved by the U.S. Food and Drug Administration (FDA) on December 10, 1990, and marketed in the United States in 1991 by Wyeth Pharmaceuticals.
[24] By 1996, more than 50,000 women had filed lawsuits, including 70 class actions, against Wyeth or its subsidiaries, or doctors who prescribed Norplant.
[26] On August 26, 1999, after winning 3 jury verdicts, 20 pretrial summary judgments and the dismissal of 14,000 claims, Wyeth offered out-of-court cash settlements of $1,500 each to about 36,000 women who contended that they had not been adequately warned about possible side effects of Norplant such as irregular menstrual bleeding, headaches, nausea and depression.
Wyeth did not admit to any wrongdoing, saying the settlement offer "was purely a business decision," noting "our legal success has come at a steep price because lawsuits are time-consuming, expensive, and have a chilling effect on research," and that it would continue to offer Norplant and would contest "any and all new lawsuits aggressively.
[29] In August 2000, Wyeth suspended shipments of Norplant in the United States because during regular quality assurance monitoring, representative samples of seven lots distributed beginning October 20, 1999 tested within product specifications, but at the lower end of the release rate specification for shelf life stability, raising concerns about those lots' contraceptive effectiveness.
Wyeth recommended that women who had Norplant capsules from those lots implanted use backup contraception until they determined the clinical relevance of the atypically low levels of levonorgestrel release.
Wyeth also announced that due to limitations in product component supplies, they did not plan to resume marketing the six-capsule Norplant system in the United States.
Medical professionals raised concerns during a consultation process indicating preference for a product which is easier to insert.
[32] Some American legislators have unsuccessfully attempted to provide financial incentives to women on welfare who agree to use Norplant.
For example, in Kansas, Republican Kerry Patrick introduced legislation that would grant welfare recipients a one-time payment of $500 to use Norplant, followed by a $50 bonus each year the implants remained in place.
[33][34] Eleven days later the Inquirer apologized for their "misguided and wrongheaded" editorial and for their suggestion of offering incentives for Norplant use.
[38] The mayor at the time, Kurt Schmoke, pushed for laws that would give teen girls more access to Norplant.