Review 2026: Real Purity Numbers, How to Read a COA, and What Sets This Research Peptide Vendor Apart from the Competition
Most peptide vendors advertise purity. Far fewer let you verify it. The difference matters: a compound that tests at 94% is not the same as one at 99%, and a COA with no chromatogram is not evidence of anything.
Table of Contents
This review focuses on what PureRawz actually does around testing and documentation, what their certificates of analysis include, and where the gaps are. It’s intended for both independent researchers and general consumers who want to evaluate a vendor on substance rather than marketing.
What “Purity” Actually Means in Research Peptides
Purity, in this context, refers to the proportion of the target compound in a sample relative to everything else present: residual solvents, byproducts from synthesis, degradation products, or unrelated peptide fragments.
A sample at 98% purity contains 2% of material that is not the peptide you ordered. That may sound negligible. For most research applications, it is. For sensitive assays, it may not be.
There is no universal standard for “research-grade” purity, but the working range most suppliers and researchers use is 95% to 99%. Pharmaceutical-grade requires 99.5% or higher, a threshold that accounts for clinical dosing precision. Research-grade is held to a looser standard because the applications differ.
Two tests dominate purity verification:
HPLC (high-performance liquid chromatography) separates the components of a sample and quantifies the percentage of the total peak area attributable to the target compound. It tells you how much of the sample is the right peptide. It does not confirm which peptide it is.
Mass spectrometry (MS) measures the molecular mass of the compound and compares it against the expected mass for that peptide. It confirms identity. On its own, it cannot tell you the purity percentage.
Together, the two tests answer both questions: is this the right compound, and how much of the sample is actually that compound?
Purity: Advertised vs. Actual Results
This manufacturer advertises 99% purity across its catalog. The accurate summary is more nuanced.
COA minimums documented across their product pages are 98%. Customer-reported results from independent testing, circulated in research communities and reviewed for this article, typically fall between 97% and 98%. Independent 2025-2026 testing has documented a variance of 8 to 12 percentage points across different batches and compounds.
That variance doesn’t mean PureRawz is misrepresenting results. Peptide synthesis varies by batch: a lot made six months ago may test differently from the most recent production run. Batch-specific COAs exist for exactly that reason.
The practical implication: the 99% figure is a ceiling, not a guarantee. Reviewing the batch-specific COA for the compound you intend to purchase is the only way to know what that particular lot actually tested at.
MZ Biolabs: Who’s Actually Testing the Compounds
PureRawz, based in Tucson, Arizona, as its third-party testing laboratory.
MZ Biolabs holds a DEA Schedule III controlled substance license, which is relevant for research purposes and indicates regulatory standing within that specific domain. The lab has over 15,000 COAs on file across its client base. Testing methodology includes HPLC with UV detection and mass spectrometry, which covers the two core verification methods described above.
MZ Biolabs does not hold ISO 17025 accreditation (the international standard for testing and calibration labs). That’s not unusual in the U.S. research peptide space, but if ISO 17025 is a hard threshold for your work, MZ Biolabs won’t meet it.
MZ Biolabs does not test for heavy metals, bacterial endotoxins, pH, sterility, or biological activity. For cell-based or in vivo work where endotoxin contamination would confound results, you’d need supplemental testing through a different lab.
How to Read a COA
PureRawz provides batch-specific COAs on individual product pages. Each COA corresponds to a specific lot number rather than a generic claim. Here is what to verify.
Confirm the Lot Number
The lot number on the COA should match the lot number on your order documentation. A COA for a different lot is not evidence of the compound you received.
Check the HPLC Purity Figure
Look for the percentage purity listed under HPLC analysis. Confirm that a chromatogram is attached. A purity claim without the underlying chromatogram cannot be independently verified. The chromatogram shows the peak profile from the separation run, which an experienced reader can assess for anomalies.
Confirm Mass Spectrometry Identity
The MS data should list the observed molecular mass alongside the theoretical molecular mass for the peptide. A close match (typically within 1 dalton for smaller peptides) confirms the compound’s identity.
Note: What Is Not Tested
As covered above, MZ Biolabs’ COAs do not include testing for heavy metals, endotoxins, or sterility. If those parameters are relevant to your work, note their absence before use.
Check the Test Date
Peptides degrade over time. A COA dated more than a year before the product was shipped may not accurately reflect the current state of that material. Most reputable vendors generate new COAs per production batch rather than reusing old documents.
Vs. Other Vendors: Where It Actually Stands Out
The domestic U.S. research peptide market varies significantly in documentation quality. Some vendors provide COAs; others provide what appear to be COAs but are templated documents without batch-specific data, or COAs that list only a purity figure without the underlying chromatogram.
A few things actually differentiate from the median domestic vendor:
The COAs include chromatograms, not just a purity number. That matters because a number without the underlying chromatogram can’t be independently verified. Most vendors don’t include them.
Testing is third-party. MZ Biolabs conducts and signs off on results; PureRawz doesn’t self-certify. Self-certified COAs from in-house testing are common in this market and offer weaker verification.
Catalog breadth with consistent documentation
This manufacturer carries over 200 compounds, including BPC-157, TB-500, CJC-1295, Semaglutide, GHK-Cu, and a range of SARMs and nootropics. COA coverage extends across the catalog rather than being limited to flagship products.
Founded in 2016, it has been operating for nine years. No documented fraud history or federal enforcement actions related to its peptide or SARM catalog. A September 2025 FDA warning letter addressed Tianeptine specifically, which sits entirely outside that catalog.
Regulatory relevance
In February 2026, HHS Secretary RFK Jr. announced the removal of 14 of 19 previously restricted peptides, including BPC-157 and TB-500, from the FDA’s Category 2 “do not compound” list. Full Category 1 reclassification requires individual PCAC review; that process is scheduled to begin in July 2026. PureRawz’s catalog includes both compounds. Regulatory standing in this space can change quickly; confirm the current status of any compound in your jurisdiction before purchase.
Who It Is and Is Not Right For
PureRawz is a reasonable sourcing option for:
Researchers who need a wide domestic catalog with batch-specific, third-party-tested COAs and do not require ISO 17025 accreditation, endotoxin data, or sterility certification. The vendor’s documentation practices sit above the median for the U.S. research peptide market.
General consumers purchasing compounds for non-clinical research use who want verifiable purity data rather than a marketing claim.
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