Peptides vs Meds/Drugs

Can someone with more knowledge on this explain: what the core mechanistic differences are betw the two ?

There's this prevailing idea that peps are "healthier" because they merely signal an action to the cell: produce more blood vessels, activate glucagon, make T cells sharper, etc. So in a more "natural" way, with little side effects.

While meds, not endogenous or naturally occurring, force an action in the body which spills into imbalances and side effects.