Is 7alpha-Methyl-ethinyl estradiol a metabolite of tibolone but a chemical stress artifact?
7alpha-MEE is not a metabolite of tibolone but is a chemical artifact generated during analytical procedures with derivatization. Using LC-MS/MS without derivatization, 7alpha-MEE cannot be demonstrated in plasma from postmenopausal women after single or multiple doses of tibolone.
Indicators for the validity of the clinical data analyzed were found. Some special internal clinical and regional conditions were identified as contributing to the quantitative differences between the two university departments.