DIFFERENCES IN SERUM FOLLICLE-STIMULATING-HORMONE UPTAKE AFTER INTRAMUSCULAR AND SUBCUTANEOUS HUMAN MENOPAUSAL GONADOTROPIN INJECTION

Objective: To determine the difference in FSH bioavailability from IM and SC injection sites. Design: Menotropin was injected into either an IM or SC site in women undergoing ovarian suppression with leuprolide acetate. Serial serum samples were obtained over 96 hours. Setting: A cademic tertiary care institution. Patients: Seven volunteer cycling w omen. Main Outcome Measures: Follicle-stimulating hormone, LH, and E(2 ) were determined in serial serum samples. Results: Peak serum FSH lev els were higher and occurred earlier after IM injection than after SC injection. Computed absorption rate constants for FSH after IM and SC injection differed significantly. Conclusions: The pharmacokinetics of FSH differ after a single IM or SC injection.