Evidence & research
Evidence level
A grading of how much confidence the underlying research supports — from large human trials down to cell studies and anecdote.
In plain terms
Pepperz grades each compound in the index by evidence level, because "studied" is not a binary. A compound with two randomised human trials and one with a promising rat study are both, technically, "researched".
Grading is where an honest reference does its most useful work, and where a vendor blog has the least incentive to be accurate.
Guides that use this term
BPC-157 is one of the most confidently discussed peptides on the internet. PubMed indexes no completed randomized controlled trial of it in humans. Here is what does exist, and what it can support.
TB-500 is a fragment of thymosin beta-4, and the human trials people cite for it were run on the full-length protein. Here is what each has actually been shown to do.
A 2026 meta-analysis found lean mass falls in absolute terms on GLP-1 drugs while rising as a proportion of body weight. Both statements are true, and they explain the entire argument.
Sources
Educational reference only. Pepperz does not provide medical advice, diagnosis, treatment, prescribing guidance, or dosing recommendations.