And here's where I can add something of useful I hope. For the last few years I've been all over the grid trying to find SOMETHING to make me feel human again. Multy vitamins are a nice touch, but not quite good enough and the little man below just wasn't much of a gamer with these. I suspected LowT and started trying the varieties from GNC like most suckers. I'd go in the store expecting to see ramped up BBers but it never registered in my dense head that there were only pudgy bastards in there - just like me. I tried SEVERAL testosterone "boosters" and actually felt good results on at least one. It took a couple weeks for me to figure out those results were from 5-600mg of caffeine. Caffeine and placebo are some amazing shit and both were at play here 'cuz I REALLY wanted this to work!
Then I finally got my doctor off of hypothyroid and testing me for low T for my symptoms. Once I started getting the shots, I never looked back at the crap GNC sells.
For the record as well, I DID have one item from GNC that was useful in getting Junior up and it worked with flying colors! Then it was pulled from the market... Why? It was found to contain both Tadalafil AND Verdanifil - 2 controlled substances used in cialis and lavitra. So yeah, there have been cases of OTC pills working, and those same pills were found to be illegal and removed from the market.
To sum it up for easier thinking: Test boosters, erectile pills and other "supplements" sold OTC work with your body in a suggestive manner. They give you a tingle by raising your caffeine levels and such and you "think" somethings up, but in no way actually interact with your body to directly affect testosterone and such. Just the same with the OTC products claiming "If you experience an erection lasting longer than 4 hours...", yeah, aspirin could offer this same disclaimer - it doesn't guarantee it actually has ANY affect on erections. That's all marketing.