How to Verify a Peptide COA: Free Batch Lookup

You have a vial. The vendor says 99% purity. Maybe they even emailed you a PDF labeled Certificate of Analysis. But is that COA batch-specific, or a generic placeholder? Is the lab a real independent third-party, or the vendor's own in-house team? And does the batch number on your label actually match a result in a public database? The COA lookup at peptidesrated.com/coa answers those questions in about 30 seconds. This guide walks you through how to use it, what each result means, and what to do when your batch isn't found.

What a COA Actually Proves

A Certificate of Analysis (COA) is a lab document confirming test results for a specific batch of a compound. For research peptides, a real COA tells you three things: what compound was tested, what its purity is by High-Performance Liquid Chromatography (HPLC), and which lab ran the analysis.

The third item, which lab, is the one most buyers skip. A COA issued by the vendor's own in-house team proves nothing: they have every incentive to report favorable numbers. A COA from an independent third-party lab (Janoshik Analytical, Finnrick, or Freedom Diagnostics) carries weight because the lab's reputation depends on accurate results regardless of outcome.

Honestly, the in-house versus third-party distinction matters more than the purity number itself. If you cannot identify which lab ran the test, the result is unverifiable and should be treated as such.

Why Your Specific Batch Number Matters

The same vendor can ship significantly different purity levels across batches. Suppliers reformulate, change raw material sources, switch synthesis partners, and have quality control failures that affect individual lots, not their entire catalog.

From what we've seen in the database, purity variance of 5 to 10 percentage points within the same vendor across different batch dates is not unusual. A vendor with a 99% average rating could have shipped a 94% lot last quarter. Without batch-level verification, you are trusting a brand average, not your specific vial.

The batch number printed on your label, usually a lot number, batch ID, or alphanumeric code, is the key that unlocks the batch-specific COA. The lookup tool searches against that identifier, not just the vendor name.

Three Ways to Search the COA Lookup

The COA lookup at peptidesrated.com/coa accepts three types of search input. Use whichever fits your situation.

Search by Batch Number

This is the most precise search and the one to use when you have a vial in hand. Enter the batch number exactly as printed on your label.

Example: search T100/2025-12-18-B and the tool returns an InnoPeptide Tirzepatide batch at 99.91% purity from Janoshik Analytical. That specific batch, independently verified, in seconds.

Batch number formats vary by vendor: some use alphanumeric codes, some use date-based IDs, some use sequential lot numbers. If your first search returns no results, try entering just the numeric portion of the code, or the date segment if the label uses a date-format ID.

Search by Vendor Name

Searching by vendor name returns all indexed COAs for that supplier, across all peptides and batch dates. Use this for due diligence before placing an order.

Example: search Astro Peptides and you get their full multi-batch lab history. Look for two things: consistency of lab (do they use the same testing partner repeatedly?) and consistency of results (are purity numbers clustered around 98 to 99%, or bouncing around?). Consistency signals quality control. Inconsistency warrants a direct question to the vendor before you order.

Search by Peptide Name

Searching by peptide name (BPC-157, Semaglutide, Tirzepatide, TB-500, etc.) returns all indexed COAs for that compound across every vendor in our database. This is the cross-vendor comparison view.

If you're deciding between two or three suppliers for the same peptide, this search lets you compare their actual batch results side by side, not their marketing claims. BPC-157 is the most-indexed peptide in our database: the cross-vendor spread here is instructive.

How to Read Your Results

When a match comes back, the result row shows:

1. Vendor: the supplier who submitted or sold this batch

2. Peptide: the compound tested

3. Batch / Lot: the specific batch identifier from the lab record

4. Purity %: HPLC-measured purity as a percentage of the total chromatogram area attributed to the target compound

5. Pass / Fail: whether the batch meets the 98% threshold we apply as a minimum research standard

6. Lab: which third-party lab conducted the analysis

7. Test Date: when the analysis was performed

8. Source: a direct link to the original COA or lab report

The 98% pass threshold is our standard, not a regulatory mandate. The research peptide market has no FDA purity requirement. We use 98% because it aligns with pharmaceutical-grade standards for injectable-quality compounds. Below 95% is a real concern: the remaining 5%+ of unknowns can represent truncation sequences, byproducts, or residual solvents, and you should know what that means before injecting anything. For a deeper walkthrough of each COA field, see how to read a peptide COA.

The Recency Window

Our database shows results from the current active vendor catalog. We prioritize recent records because peptide batches from a year ago may have been reformulated, pulled, or replaced by the vendor.

If you need an older batch record or are doing historical research, click the Source link on any result. That link goes directly to the lab's own record on Janoshik, Finnrick, or Freedom Diagnostics, which maintain their own archives beyond our index window.

For the most current batch data, the records in our database reflect what is actively circulating in the research market right now.

What to Do When Your Batch Is Not Found

No match does not automatically mean the batch is bad. It means we do not have it indexed yet. Three options:

1. Ask the vendor. Any legitimate research peptide supplier should be able to provide the original third-party COA for your specific batch number. Ask for it. If they cannot produce one, or refuse, that is a significant yellow flag.

2. Submit it to us. If you have a COA from your vendor naming a specific third-party lab, contact us via the email on our Contact page. We review and index verified results from named independent labs.

3. Treat a refusal as a yellow flag. A supplier who cannot produce a batch-specific COA from a named independent lab has a sourcing transparency gap. That alone may not disqualify them, but it means you cannot independently verify what you received.

For the full pattern list of supplier warning signs, see 7 red flags when buying research peptides.

The Three Labs We Index

We aggregate results from three independent testing labs: Janoshik Analytical (Prague, Czech Republic), Finnrick (Texas, USA), and Freedom Diagnostics. Each maintains a public database that buyers can cross-reference directly, independent of our tool.

Here's what matters about the structure: these labs have no financial stake in a favorable result. Janoshik charges vendors to test their peptides and publishes results regardless of outcome. Finnrick offers free testing to US residents and publishes everything publicly. That alignment of incentives is the whole point. A vendor's in-house lab tests its own inventory and reports to itself.

For a detailed breakdown of how Janoshik conducts its testing, what the methodology covers, and where the known limitations are, see Janoshik Testing Explained.

Suppliers like Verified Peptides, which has 400+ Janoshik reports in the public database, set the transparency standard the rest of the market should match. Browse ranked suppliers and their COA track records at peptidesrated.com/browse.

FAQ: Peptide COA Verification

What purity percentage should I look for?

98% or above is the minimum we apply for research-grade peptides. Results of 99%+ are best-in-class. Below 95% warrants serious scrutiny: the unknowns in the purity gap can have biological activity or introduce contamination risk at injectable concentrations.

Does a COA prove the peptide is safe to inject?

No. A COA confirms purity and compound identity by HPLC. It does not test for bacterial contamination, endotoxins, heavy metals, or sterility. Third-party HPLC is the most important single data point on a research peptide, but it is not a complete safety profile.

How often is the database updated?

Continuously, as new batches are indexed from our lab partners. Each result row shows the test date alongside the purity figure. For records older than our index window, follow the Source link to the originating lab's own archive.

Can I verify a COA my vendor emailed me?

Yes, if the COA names a specific third-party lab and includes a batch number. Search that batch number in our lookup. A matching result with the same purity number confirms the COA is independently verifiable. A mismatch on purity for the same batch and lab is a significant red flag.

Is the lookup tool free?

Yes. The COA lookup at peptidesrated.com/coa is free with no account required. We built it to make batch verification standard practice in the research peptide community.

Sources

1. PeptidesRated COA Lookup Tool: https://peptidesrated.com/coa

2. Janoshik Analytical (worldwide peptide testing): https://janoshik.com/

3. Finnrick peptide testing (6,813+ samples tested across 204 vendors, 15 peptides): https://www.finnrick.com/

4. How to Read a Peptide COA (PeptidesRated): https://peptidesrated.com/blog/how-to-read-a-peptide-coa

5. Janoshik Testing Explained (PeptidesRated): https://peptidesrated.com/blog/janoshik-testing-explained

6. Elsayed YY et al. (2025). Regulatory guidelines for the analysis of therapeutic peptides and proteins. J Pept Sci. PMC11806371: https://pmc.ncbi.nlm.nih.gov/articles/PMC11806371/