Comparative Pharmacology
Head-to-head clinical analysis: ELLA versus PLAN B ONE STEP.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ELLA versus PLAN B ONE STEP.
ELLA vs PLAN B ONE-STEP
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Selective progesterone receptor modulator (SPRM) with antagonistic and partial agonistic activity. Delays or inhibits ovulation, alters endometrial receptivity, and impairs implantation.
Levonorgestrel is a progestin that prevents pregnancy primarily by inhibiting ovulation and altering cervical mucus to impede sperm penetration. It may also interfere with fertilization and implantation.
30 mg orally as a single dose within 120 hours of unprotected intercourse.
One 1.5 mg tablet orally as a single dose within 72 hours of unprotected intercourse.
None Documented
None Documented
Terminal half-life is approximately 24.7 hours (range 20–30 hours), allowing for single-dose emergency contraception.
Terminal elimination half-life is approximately 24 hours (range 16-32 hours) for levonorgestrel. This supports single-dose administration for emergency contraception.
Primarily fecal (≈86%) with minimal renal excretion (≈10%). Biliary elimination of metabolites is also significant.
Renal (approximately 50%), with fecal elimination accounting for the remainder. Metabolites are excreted primarily in urine as glucuronide conjugates.
Category C
Category C
Emergency Contraceptive
Emergency Contraceptive