Table 1.

Advantages, limitations, and knowledge gaps in key aspects of OF drug testing.

	Advantages	Limitations	Knowledge gaps
OF collection	Easy, noninvasive; no need for privacy; sex neutral	Between- and within-device variability in drug recovery, stability, volume collected; dry mouth reduces OF volume; stimulation can affect test results	Establish a standardized procedure for sample collection
OF analysis	Basic drugs concentrate in OF; parent drug frequently present	Few stability data; low volume compared to urine; possible instrumentation issue due to OF buffer	Need to develop multianalyte LC-MS or GC-MS methods; need stability studies for all doping agents
Substance banned at all times	Endogenous steroids and peptide hormones detectable in OF; OF concentrations correlate better with blood than urine	Unable to differentiate endogenous production and exogenous contribution; T/E OF irrelevant; enzymatic activity in salivary glands; detection windows may be too short for synthetic steroids	Need to provide disposition data for majority of these compounds; evaluation of OF contamination when drugs given by spray; controlled administration studies needed
Substance banned in competition only	Several agents already extensively studied in OF; short detection windows; OF concentrations correlate well with blood	Weak bases sensitive to OF pH change; enzymatic activity in salivary glands for glucocorticosteroids	Need synthetic glucocorticosteroid data; evaluation of OF contamination when drugs given by spray (other than cannabinoids); controlled administration studies needed