Guides

What FDA 503A categories mean, why so many research peptides are Category 2, and what the 2026 changes and July PCAC meeting could bring.

Many peptide “studies” have only four to twelve people. The rule of three explains why “no side effects reported” in a tiny trial tells you almost nothing about safety.

What the five melanocortin receptors (MC1R–MC5R) do, the peptides that activate them, and why one non-selective agonist can tan skin or change desire.

What the gonadorelin label actually documents, why kisspeptin-10 has almost no human safety data, and why the side-effect tables circulating for it are invented.

Thymosin alpha-1 side effects per the Zadaxin label and randomized trials: well tolerated (under 1% drug-related AEs), plus what is not established and the real grey-market risk.

How the WADA Prohibited List captures research peptides through S0, S2 and S4 catch-alls, why strict liability applies, and why not being named is not protection.

Bacteriostatic water is generally good for about 28 days after first puncture. Here is where that beyond-use date comes from and how to handle an opened vial.

What agonist, partial agonist, antagonist and inverse agonist actually mean at a receptor, and why potency and efficacy are not the same thing.

Tachyphylaxis, tolerance, and downregulation are not synonyms: two describe how fast a response fades, one is the receptor-level mechanism behind it.

Injection site rotation is not just moving around a bit. The size of the area matters more than any other risk factor.