Can you tell me what is norplant (levonorgestrel)?

No longer available. Norplant (levonorgestrel) is not available anymore in the United States. There is a similar device called implanon. It is a thin, small cylindrical structure that is easily inserted under your skin. It lasts for three years. It has no estrogen in it. It is 99% effective. It can be associated with irregular bleeding.
"Norplant" Levonorgestrel is an implantable source of progestins (progesterone derivative) which provides excellent birth control, although not quite as well as combination oral contraceptives. Your periods may become irregular, as ovulation is often delayed. .