How we rate the research
Every peptide page is checked against the criteria on this page before it is published, by the PeptideSearch Editorial Team.
Supplier listings are not rated. They follow a separate policy: How we list suppliers.
What each badge means
- Approved medicine
- The FDA has approved at least one version of it as a medicine for a specific use, after large studies in people.
- Tested in people
- Real studies in people have been published, but nothing is approved. These are usually small, early studies.
- Animal studies only
- The research is in animals. There may also be a few loose reports from people, but no proper study.
- Very early research
- The work is on cells in a lab dish or tissue samples, often from one lab only, with nobody else repeating it yet.
What we include
To move up to "Tested in people" a peptide needs at least one published study in people where the people who took it were compared against a group who did not. A single small study with no comparison group does not count, and neither does a registered trial that has not published results yet – a trial is a plan, not a finding. When there is a study in people but no comparison group, the badge reads "Almost all animal studies" instead.
- A study has to be published in a real journal and be about the peptide itself.
- Every study gets a short plain line, like "Rat study, 2016", so you can tell what kind of research it is before you open it.
- Trials show their registry number, stage, current status and what was being treated.
- For sellers we record only things we can check: whether they publish test results from an outside lab, and where they say orders ship from.
When a page shows a sample
A few compounds – glutathione and NAD+ among them – have tens of thousands of published papers. No list we keep by hand can be all of them, so those pages say so at the top of the research list: what you see is a selected sample, and we print the real total next to it.
- A page is marked as a sample when the wider literature runs past about 2,000 papers and we hold under 5% of it. Both numbers come from counting the literature itself, not a list we keep.
- Up to 200 papers per compound are pulled in four passes: most relevant, published trials only, and the same two again limited to older years and sorted by how often other researchers have cited them. That last pass is there so the big early trials a drug was approved on are in the list, not buried under this year's commentary.
- The list is refreshed weekly, and the real total is re-counted on the same schedule. The date of the last count is printed on the page.
How we record the FDA compounding categories
FDA publishes its categories for substances put forward for compounding as two documents, one for small pharmacies (503A) and one for outsourcing facilities (503B). Some entries are limited by how the substance is given – GHK-Cu is Category 1 for every route except injection, GHRP-2 is Category 1 for everything except injection and nasal use and Category 2 for those two. We store each entry as written, with its routes, and show one line per entry. We never fold a split entry into a single category, because doing so states the opposite of the entry for half of its uses.
FDA states it does not intend to place bulk drug substances nominated on or after 7 January 2025 into these categories. The category document is therefore not updated for new nominations — an older document date reflects a frozen process, not a lapsed one.
Where the data comes from
Everything on the site is entered by hand and reviewed before it goes live. Paid listings are labeled in plain text wherever they show up, and they never change a badge or which studies we list.