Differences in serum follicle-stimulating hormone uptake after intramuscular and subcutaneous human menopausal gonadotropin injection.

ABSTRACT

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: Academic tertiary care institution. PATIENTS Seven volunteer cycling women. MAIN OUTCOME MEASURES: Follicle-stimulating hormone, LH, and E2 were determined in serial serum samples. RESULTS: Peak serum FSH levels 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.