Metabolites are intermediates in energy conversion, present in low abundance with rapid turnover rates typically on the scale of seconds to an hour.

“so you know metabolites are intermediates in the process of converting what we eat into usable energy and protein biomass and these things and so they're really you know relatively low in abundance and they're flowing very very fast so they're completely different than parts of our body like neurons that are going to sit there maybe for our entire lifetime okay here the metabolites are meant to be made and used somewhere on the time scale depending on the metabolite of roughly a second to you know roughly an hour maybe for metabolites in the bloodstream”