Do many supplements state the half life on the label? Not in my experience. You’d need full pharmacokinetic research into each ingredient and their individual compounds to have that. And since some herbal ingredients can have dozens of compounds identified in them, it wouldn’t be realistic.
Essentially you’d need to look up each individual ingredient. And even then, good luck, since the compounds within ingredients will have a varying half life.
For instance, pulling Olive Leaf Extract from the Inhibit E label: it’s extracted for Oleuropein, which has some half life (which probably varies based on fasted or fed state when consuming), but the extract might also contain tyrosol, apigenin, kaempferol, luteolin etc and those will all have a different half life.
Basically, half life is interesting when we’re looking at single ingredients, but when you have a multi-ingredient product, there’s going to be so much variability. Also there’s just individual variability in how people process ingredients. If you look into pharmacokinetic research with prescription drugs, there’s quite a bit of variability in metabolism.
Because of this, if you’re trying to be most optimal, I’d evenly spread out the dosing throughout the day and be consistent day to day. If doing 3 caps, then maybe like 8am, 2pm, 8pm… if doing 2 caps, maybe 8am and 8pm… you get the picture. It’s not like caffeine which you feels acutely, so I’d just be consistent daily.