That does not prove those routes cannot work
A 2013 survey of intranasal glutathione users reported fewer sinus infections among many respondents
Chen J, Xie JJ, Shi KS, Gu YT, Wu CC, Xuan J, Ren Y, Chen L, Wu YS, Zhang XL, Xiao J, Wang DZ, Wang XY (2018) Glucagon-like peptide-1 receptor regulates endoplasmic reticulum stress-induced apoptosis and the associated inflammatory response in chondrocytes and the progression of osteoarthritis in rat
LiquiCarn contains L-carnitine, which is an amino acid supplement that helps support carnitine deficiency as well as cardiovascular, liver, and cognitive health function in dogs and cats
Given thats as good as six months, its safe to say you wont benefit from cycling l-carnitine on and off