Apollo runs third-party testing through Janoshik, an independent analytical lab widely used in the research peptide space. Every batch is tested by HPLC, which is high-performance liquid chromatography, the standard method for measuring how much of a sample is the intended compound. Results carry a QR code and a verification key, and recent lots clear a baseline of 98% or higher, frequently landing at 99%+.
One detail worth crediting: the testing is blind. The manufacturer is submitted to the lab as "Unknown," which removes a path for the lab to bias a result toward a known client. Apollo also reported generous fill on at least one product, with 25.48 mg measured in a vial labeled 20 mg, an overfill of about 127%.

