There are also some who complain of joint pain when using Winstrol. As a steroid that does not aromatize there will be no water retention but the “dry feeling” may not be what many think it is. Most who use the steroid will be physique athletes or gym rats during a cutting phase. They will also typically add it into a plan late in the diet once they’re already lean. Typically, when you become very lean, bodybuilding lean, this makes the joints a little uncomfortable. With or without Winstrol this discomfort could potentially exist. As for pro athletes who have nearly every last steroid at their disposal, remember, if Winstrol weren’t effective in competitive sports so many athletes wouldn’t make it a primary and favorite choice. In fact, the combo of Winstrol with low doses of Nandrolone is a very common stack among many athletes, and this stack will greatly eliminate any potential joint discomfort should it exist.
Detailed structural information on metabolites serving as target analytes in clinical, forensic, and sports drug testing programmes is of paramount importance to ensure unequivocal test results. In the present study, the utility of collision cross section (CCS) analysis by travelling wave ion mobility measurements to support drug metabolite characterization efforts was tested concerning recently identified glucuronic acid conjugates of the anabolic-androgenic steroid stanozolol. Employing travelling-wave ion mobility spectrometry/quadrupole-time-of-flight mass spectrometry, drift times of five synthetically derived and fully characterized steroid glucuronides were measured and subsequently correlated to respective CCSs as obtained in silico to form an analyte-tailored calibration curve. The CCSs were calculated by equilibrium structure minimization (density functional theory) using the programmes ORCA with the data set B3LYP/6-31G and MOBCAL utilizing the trajectory method (TM) with nitrogen as drift gas. Under identical experimental conditions, synthesized and/or urinary stanozolol-N and O-glucuronides were analyzed to provide complementary information on the location of glucuronidation. Finally, the obtained data were compared to CCS results generated by the system's internal algorithm based on a calibration employing a polyalanine analyte mixture. The CCSs ΩN2 calculated for the five steroid glucuronide calibrants were found between 180 and 208 Å(2) , thus largely covering the observed and computed CCSs for stanozolol-N1'-, stanozolol-N2'-, and stanozolol-O-glucuronide found at values between and Å(2) . The obtained data corroborated the earlier suggested N- and O-glucuronidation of stanozolol, and demonstrate the exploit of ion mobility and CCS computation in structure characterization of phase-II metabolic products; however, despite reproducibly measurable differences in ion mobility of stanozolol-N1'-, N2'-, and O-glucuronides, the discriminatory power of the chosen CCS computation algorithm was found to be not appropriate to allow for accurate assignments of the two N-conjugated structures. Using polyalanine-based calibrations, significantly different absolute values were obtained for all CCSs, but due to a constant offset of approximately 45 Å(2) an excellent correlation (R(2) = ) between both approaches was observed. This suggests a substantially accelerated protocol when patterns of computed and polyalanine-based experimental data can be used for structure elucidations instead of creating individual analyte-specific calibration curves.