|Type of progestin||Levonorgestrel.||Etonogestrel.||Levonorgestrel.||Levonorgestrel.|
|Number||2 rods.||1 rod.||2 rods.||6 capsules.|
|Lifespan||Up to 5 years.||3 years.||4 years, may be extended to 5.||Up to 7 years.|
|Effectiveness and Client's Weight (see also Implants, Question 9)||80 kg or more: Becomes less effective after 4 years of use.||Weight has no known impact on effectiveness.||80 kg or more: Becomes less effective after 4 years of use.||80 kg or more: Becomes less effective after 4 years of use.
70–79 kg: Becomes less effective after 5 years of use.
|Availability||Expected to replace Norplant by 2011.||Primarily available in Europe, Asia, and Africa. Also approved for use in United States.||Primarily available in Asia and Africa.||Being phased out of use (see Implants, Question 11).|