Methodology: how our peptide profiles are made

PepCycle summarises published peptide research in plain language. This page explains which sources we use, how the research level is rated and how often the content is updated.

Sources

We rely on peer-reviewed studies (PubMed, journals such as NEJM, Lancet, JAMA, BMJ), trial registries (clinicaltrials.gov) and announcements from regulators such as the FDA and EMA.

Results from company press releases (e.g. phase 3 topline data) are labelled as such until the full publication is available. Animal and cell studies are explicitly marked as preclinical.

Every profile lists its sources with links so you can check the original papers yourself.

Research level (1–5)

The rating describes how robust the human evidence is – not how well or how safely a peptide works. The criteria for each level are listed below.

  1. 1/5 – Preclinical data only (cell or animal models) or no published human studies.
  2. 2/5 – Few, small or uncontrolled human data; mostly animal studies.
  3. 3/5 – Several controlled human studies or approval in a niche indication; evidence still patchy.
  4. 4/5 – Large phase 3 trials or regulatory approval; long-term data still limited.
  5. 5/5 – Approved, large randomised trials and robust long-term safety data.

Updates

We review the profiles every quarter for new studies, trial results and regulatory decisions. New findings appear as a “Research update” in the profile and are collected on the “New in research” page.

Every profile shows when it was last updated.

Doses and calculators

Doses reflect what has been studied. They are not recommendations and do not replace medical advice.

The calculators are purely mathematical: they convert your inputs (vial content, water volume, dose) into concentration and syringe units.

Advertising and partners

Some pages of the website show a partner shop (Kronen Peptide) with a discount code. These notices are recognisable as partner offers; the research level is assigned according to the criteria described here.

Found a mistake?

If you spot an error or a missing study, let us know via the contact page – we review every report.