Labdoor tested best-selling pre-workout supplements for active ingredient content and heavy metal (arsenic, cadmium, lead, mercury) contamination.
Key active ingredients tested in this batch include creatine, beta-alanine, tyrosine (as L-tyrosine and N-acetyl-L-tyrosine (NALT)), arginine (as L-arginine HCl and arginine alpha-ketoglutarate (AAKG)), caffeine, and taurine.
All products in this report were screened by ICP-MS (Inductively Coupled Plasma-Mass Spectrometry) for the presence of 4 key heavy metals: arsenic, cadmium, lead, and mercury. The heavy metal limits used are set by USP.
Collective data for this batch analysis relied on analytical chemistry methods including HPLC (High Performance Liquid Chromatography) to quantify amounts of individual amino acids and caffeine, and ICP-MS (Inductively Coupled Plasma-Mass Spectrometry) to determine heavy metal (arsenic, cadmium, lead, mercury) load. Products from manufacturers previously cited by the FDA for using illicit stimulants were also screened by HPLC for illicit stimulants.