Which method of contraception offers adolescents the longest duration of protection?

The levonorgestrel intrauterine system (LNG-IUS) provides adolescents with the longest duration of protection among the options given. This form of contraception is designed to be effective for up to five years, making it a highly convenient choice for long-term prevention of pregnancy without the need for frequent intervention.

The LNG-IUS works by releasing a small amount of the hormone levonorgestrel directly into the uterus, which thickens the cervical mucus and thins the uterine lining, reducing the likelihood of sperm reaching an egg and preventing implantation of a fertilized egg. Its long duration of effectiveness alleviates the need for daily compliance, which can be particularly beneficial for adolescents who may struggle with the routine of taking a daily pill.

Other options, such as the NuvaRing and spermicidal suppositories, offer shorter durations of effectiveness. The NuvaRing needs to be replaced monthly, while spermicidal suppositories must be used during each act of intercourse, which can lead to less reliable protection if adhered to inconsistently. Although the levonorgestrel implant does have a long duration of action (up to three years), it still does not provide as long-lasting protection as the LNG-IUS. Thus, the LNG