Apologies; I confused BPC-157 with TB-500, and made a horrible amalgamation.
What do you want to know? Do you have some specific goal you want achieved or curiosity that you would like satisfied?
It's been a bit since I've been involved with these things. Most of it is underground, but I can give you a quick rundown.
BPC-157 and TB-500 are regenerative peptides. BPC-157 seems to be more "global" and neuro-involved throughout the body, while TB-500 is more local and structural (joints, tendons, etc.). BPC-157 also has a (prolonged) effect in some that negates the effects of amphetamines. Subcutaneous injections of BPC-157 have helped get rid of my recurring ganglion cysts and golfer's elbow.
Semax would fall under "slavic nootropics," along with Selank, and if I remember correctly Epithalon. All have "sub-versions" of varying efficacy. F.e. all have "N-Acetyl" and "N-Acetyl Amidate" versions. NASA would be the shortened version of "N-Acetyl Semax Amidate" -- which in my experience is the "strongest." With NASA, while I was injecting it subcutaneously it brought a sort of structure to my mind I hadn't had since I was a child. It's like feeling everything is falling into place, and a loss of the feeling of helplessness.
If you've ever used noopept, it's like that except with more real and long-lasting effects. I would liken it to bromantane, too.
If not, it's difficult to explain what they are, because they're such a different class of drugs that there's no reference point to base their effects off of. Imagine that you have a drug, but instead of giving you a few hours of a noticeable "high" or "low," instead you get a small, but perceptible shift in how you view the world, and how you filter all the information coming in. Like a micro-micro-micro dose of LSD. No high, no impairment, just a beneficial "shift" in your perception that lasts for an indeterminate, but long time.
A few of my friends were career-researchers and likened these effects to be genomic (subtly altering the expression of genes all around the body) rather than physical (that is, simple physical reactions like consuming more electrolytes would cause you to hold more water, and become bloated, because electrolytes attract and "hold" water; or how drunkenness is simply a temporary shift in the delicate GABA/glutamate balance in your brain). The purely "physical" drugs require constant re-dosing to be effective, while the more genomic ones (such as peptides) can have long-lasting effects even after they've been ceased.