Questions & answers.

A COA (Certificate of Analysis) is a document from an independent laboratory confirming the identity and purity of a compound. A legitimate COA includes the compound name, batch number, purity percentage (typically measured by HPLC), lab name, and test date.

Why it matters: Without a COA, there is no independent verification that what is in the vial is actually the stated compound at the stated purity. Some vendors publish COAs from the Chinese raw material supplier — this is not the same as third-party testing of the finished product.

PeptideCompare only accepts COAs from independent accredited laboratories (e.g. Janoshik, Liquilabs, VLAB, ColmaR). Our COA Guide explains what to look for.

The ranking is calculated from three factors:

Badges (CMI Verified, COA Verified, Product Verified) are displayed as trust indicators but do not affect the ranking score. The algorithm is identical for all suppliers — no paid placement influences the comparison result. Only the data changes the rank.

PeptideCompare uses three verification badges, each earned through independent verification:

This is the highest badge for a supplier and goes beyond the standard COA purity check: it requires a full test panel per batch — covering identity, 7 heavy metals, endotoxins and microbial contamination — verified through an independent lab (Liquilabs). It's shown as a per-supplier badge, not per product. See our Quality & badges page for the full verification system.

Product Verified looks at three things on a physically ordered sample: reconstitution (does the freeze-dried powder dissolve fully and clearly in bacteriostatic or sterile water, without clumping or cloudiness), appearance (a properly freeze-dried "cake" should be uniform and intact — shrinkage, crumbling or discolouration often signals heat exposure or a poor lyophilisation cycle), and post-reconstitution stability (does the solution stay clear over several days to weeks in the fridge, or does precipitate appear).

This badge involves no human or animal testing.

Prices are manually verified by checking supplier websites directly. Major suppliers are checked monthly; smaller suppliers approximately every 6–8 weeks. The scan date is shown in the admin metadata.

If you spot an incorrect price, use the contact form to report it. Corrections are applied within 48 hours.

PeptideCompare checks whether a supplier's COA is still current — not older than 12 months, or already replaced following a new production batch. Suppliers without an up-to-date COA are followed up with directly.

No. PeptideCompare is an independent comparison initiative. Ranking is decided only by the data — price, purity and verification — never by payment. That independence doesn't mean distance: we work closely with suppliers, and the platform grows together with the community and the suppliers who invest in quality.

The platform exists to give researchers a clear, honest picture — and to give suppliers who invest in quality a fair way to stand out.

PeptideSupply.eu is a sister platform that lists supplier prices side by side without the verification layer — no ranking, no badges. PeptideCompare adds independent verification (COAs, badges, supplier assessments) on top of price comparison.

Listing is free and based on meeting basic quality criteria: a working EU-delivery web shop, at least some publicly available COA documentation, and no credible evidence of product mislabelling. There is no fee to be listed.

There are no paid plans or promotional packages of any kind — listing, verification and placement are entirely free, and nothing can be purchased to influence a supplier's position. Genuine engagement with the community is valued, though: suppliers who actively contribute — through feedback, ideas, or other support for the platform — naturally tend to earn more visibility over time. That never changes the facts underneath it: quality, verification and ranking stay based on real, independently checked data, not on how much a supplier engages.

To request listing, use the contact form and select "Supplier registration" as the subject. Include your website URL and a brief description of your COA testing process.

PeptideCompare has a dedicated Peptide Calculator that calculates the correct volume of bacteriostatic water (or acetic acid water) per peptide and concentration. It also generates a dose reference table.

General rule: most peptides dissolve in bacteriostatic water (BAC water). IGF-family peptides (IGF-1 LR3, IGF-1 DES, PEG-MGF) require acetic acid water (0.6%). Always use sterile technique and store reconstituted peptides refrigerated.

The 28-day guideline for multi-dose vials comes from a microbial challenge test standard, not from the preservative (typically benzyl alcohol) itself decaying — the two clocks don't run at the same speed for every formulation. See our article Why bacteriostatic water gets 28 days for the full explanation.

A cloudy vial or incomplete dissolution usually traces back to one of a few documented, non-mysterious causes described in the pharmaceutical literature — not simply "bad water". See our article Why a peptide solution turns cloudy or won't dissolve for the documented causes.

It depends on the form: for lyophilized (freeze-dried) powder, colder generally wins. For already-reconstituted peptides, repeated freeze-thaw cycles can cause more damage than fridge storage. See our article Fridge vs. freezer for the detail per case.

This is a common search, but it's worth separating consumer expectations from what research peptides actually are. In laboratory and preclinical studies, individual compounds are investigated for a wide range of biological mechanisms — cell signalling, growth-factor pathways, tissue-repair processes and more — depending on the specific peptide.

These findings describe biological activity observed under controlled research conditions, not verified effects in humans. PeptideCompare does not make efficacy claims for any compound listed here, and nothing on this site is medical advice.

If you're researching a specific compound, its Encyclopedia entry summarises the published literature with source citations.

Yes — as with any biologically active substance, research peptides carry both documented and undocumented risks that vary significantly by compound. Because most are not approved medicines, there's no regulatory safety monitoring, and long-term human-safety data is often limited or absent.

Risk factors discussed in the literature include impurity or contamination — why COA verification matters, see our COA Guide — incorrect handling or storage, and compound-specific effects that are still being studied.

This is general information, not medical advice. Talk to a doctor before making any decision involving human use.

Some peptides marketed in skincare — copper peptides such as GHK-Cu among them — are studied in cosmetic-science and laboratory research for effects on skin structure and collagen synthesis.

The research-grade compounds listed on PeptideCompare, however, are sold for laboratory research use only. They are not formulated, tested or approved as cosmetic or topical products for human use, and PeptideCompare makes no cosmetic or medical efficacy claims for any of them.

See the GHK-Cu entry in our Encyclopedia for the published research on that specific compound.

Thousands of natural peptides have been identified in the human body, but only around 300 currently have confirmed bioactivity. See our article Your body makes thousands of peptides for what that gap means.

For most protocols discussed in the literature, NMN in tablet form is reported as more practical, better absorbed, and more cost-effective than direct NAD+ — see our full comparison in NMN tablet vs NAD+ injection. This is general research information, not a recommendation for personal use.

Senolytics are compounds studied for their ability to clear senescent cells — cells that accumulate with age and release inflammatory signals that can damage surrounding tissue. Senomorphics, a related category, are studied for neutralising those signals instead of clearing the cells. See our article Senolytics & senomorphics for the detail.

On the unregulated research market, a label is just a claim until an independent lab confirms it — usually via HPLC for purity and mass spectrometry for identity. See our article How peptides are tested for how testing works, where self-reported COAs fall short, and options for testing a sample yourself.

No — the literature is consistent that training, protein intake and sleep move health and body-composition outcomes by amounts that dwarf anything a peptide contributes. See our article Peptides are the last five percent for where peptides genuinely fit in that stack.