GenOne Laboratories Old Jack Extreme — tested by NSF International (Ann Arbor, MI) and RIVM (Bilthoven, NL)

Old Jack Extreme (GenOne Laboratories), tested by NSF International (Ann Arbor, MI) and RIVM (Bilthoven, NL).
This is an independent test. Whoever paid for it had no interest in the answer.

Analyte	Found
deterenol	14 mg, per serving (1 scoop, 17 g)
phenpromethamine	20 mg, per serving (1 scoop, 17 g)

Pre-workout sold in several flavours, labelled as containing isopropylnorsynephrine (a deterenol synonym). Cohen et al. 2021, Table 1: deterenol 14 ± 1.1 and phenpromethamine 20 ± 2.6 mg per serving, averaged across flavours; phenpromethamine was not declared. Samples purchased online April 2018.

Source: Peer-reviewed analysis

Measured and reported inside a peer-reviewed paper, which names its methods and reports what it found including the negatives. Cite the paper, and read its own account of how the samples were obtained.

Report: doi.org

This entry records one test of one sample. It is not a statement about any other batch, and it is not a safety assessment.