There's no human research on most of these peptides

This objection is the most defensible blanket criticism a skeptic can level at the peptide field, and the right response is not to deny it — it is to disambiguate it. The corpus on this site does not have a uniform evidence depth. Each peptide page is explicit about which level of evidence supports which claim, and the eight critic responses on this site exist in part because the underlying evidence levels vary so widely that a single posture toward "the peptide field" cannot be intellectually serious. The peptides on this list with substantial human RCT evidence: - **Tesamorelin** — FDA-approved (Egrifta) for HIV-associated lipodystrophy on the basis of a 412-patient placebo-controlled NEJM Phase III trial (Falutz et al. 2007). - **Semaglutide** — FDA-approved as Wegovy / Ozempic / Rybelsus on the basis of the STEP and SUSTAIN trials, totaling tens of thousands of randomized patients. - **Tirzepatide** — FDA-approved on the basis of SURMOUNT-1 (n=2,539) and the broader SURMOUNT/SURPASS programs. - **Retatrutide** — Phase II human data published in NEJM 2023; Phase III ongoing. - **PT-141 / Bremelanotide** — FDA-approved (Vyleesi) on the basis of the RECONNECT Phase III trials (n=1,267). - **MK-677** — 65-patient two-year RCT in older adults (Nass et al., *Annals of Internal Medicine* 2008). - **Thymosin α-1** — three decades of clinical use across 35+ countries with multiple Phase II/III hepatitis B and C trials. The peptides on this list where human RCT evidence is genuinely thin or absent: - **BPC-157, TB-500, KPV** — overwhelmingly rodent literature; the human evidence is small case series and observational reports. - **Selank, Semax, Epitalon** — Russian clinical record exists but Western RCT replication does not. - **Dihexa** — zero published human trials. - **MOTS-c** — human evidence is correlational (serum-level associations across cohorts), not interventional. - **DSIP** — modest 1980s human studies; no modern clinical-development program. - **CJC-1295** — single Phase I trial (Teichman et al. 2006); no Phase II/III for any indication. - **GHK-Cu** — substantial topical cosmetic RCTs in photoaged skin; thin systemic-injectable evidence. - **SS-31** — pivotal Phase III in primary mitochondrial myopathy was *negative*; FDA-approved for Barth syndrome only. The site is explicit about which peptide sits where on this spectrum. Pages on the rodent-only end carry framing like "the human evidence is almost entirely anecdotal" in the second sentence, not buried in a caveats section. Pages on the regulatory-approved end describe the evidence in matching detail. The honest version of the objection is not "there's no human research on most of these" — it is "the evidence depth varies enormously, and anyone treating the corpus as uniformly evidence-based is misreading it." Where the critic has a real point: a reader who lands on a "peptides" search result and assumes the category as a whole has clinical evidence comparable to FDA-approved drugs is going to be disappointed by half the corpus. The marketing of the peptide field as monolithic is a real distortion. Treating the field as one thing — either uniformly evidence-based or uniformly speculative — is the underlying error. This site exists in part to refuse that framing. Where the critic loses the thread: extending the legitimate concern about Dihexa or Epitalon to every peptide on this list — including the ones with NEJM-published Phase III RCTs — flattens the actual evidence landscape and stops the conversation before it can do useful work.