Table 2

Levonorgestrel release rates and serum levels* associated with the Jaydess® and Mirena® intrauterine systems

Time from insertionRelease rate (µg/day)Serum level (pg/ml)†
24 hours1420
60 days10
1 year6162191
2 years157
3 years559134
4 yearsNA12NA
5 yearsNA10NA
6 yearsNANA133
  • *The release rates and serum levels were not measured for Jaydess and Mirena at the same time points and in the same way.

  • †The contraceptive effect of the levonorgestrel intrauterine system is predominantly a local effect, therefore systemic serum levels should not be assumed to be an indicator of efficacy or of other local effects.

  • NA, data not available.