Horse studies show that even one bout of intense exercise to exhaustion can reduce muscle glutathione by 40%, and liver glutathione (from which muscles increase their supply) by 80%
doi: 10.2174/1871520619666191015103712 [DOI] [PubMed] [Google Scholar] 72
in human research, oral precursors raise blood NAD+ reliably, while injectable NAD+ pharmacokinetics are less fully characterized
The addition of a small fraction of propylene glycol (5%) further enhanced the solubilization capacity and reduced the particle size, while preserving the emulsion stability over time
Bachhawat AK, Ganguli D, Kaur J, Kasturia N, Thakur A, Kaur H, Kumar A, Yadav A (2009) glutathione production in yeast
Critical challenges included insufficient sample size reducing statistical power, reliance on self-reported exposure data introducing recall bias, and inadequate control for confounding factors such as smoking and alcohol consumption