For research use only. Not for human consumption.
Transparency Report · Last updated March 2026
The Reject List: Published Results From Every Batch We’ve Refused to Sell
The Industry’s Open Secret
Here’s something nobody in the research peptide industry will tell you: failed tests aren’t rare. They’re routine.
We’ve submitted batches from multiple suppliers for independent 10-panel conformity testing through Vanguard Laboratory. That includes manufacturers the research community considers the most reliable sources available. The names that show up in every Reddit thread and every forum recommendation. The ones people swear by.
Not all of their batches passed.
That’s not an indictment of any single supplier. Peptide synthesis at scale introduces real variability. Batch-to-batch inconsistencies in purity, net content, and contamination levels are a documented reality of the manufacturing process. It doesn’t matter how big the facility is, how many people vouch for them on forums, or how long they’ve been in business. It happens at mega-factories with 500+ employees. It happens at boutique labs with 20. It happens everywhere.
So why doesn’t anyone talk about it?
Browse any research peptide vendor’s website. You’ll find passing COAs. You’ll find claims about “rigorous testing” and “quality assurance.” What you won’t find is a single published failure. Not one rejected batch. Not one documented case where testing caught a problem and the company walked away from the revenue. Every vendor’s public record looks the same: 100% perfect, every batch, every time.
Think about what that implies. Either every single batch from every supplier passes every test every time (which contradicts basic manufacturing science), or companies are testing so minimally that failures slip through undetected, or they’re simply not publishing the failures because it would undermine the image they’re selling you. Pick whichever explanation you want. None of them are good.
The question isn’t whether failures happen. It’s whether your vendor tests thoroughly enough to catch them. And if they catch them, whether they have the integrity to tell you about it instead of quietly shipping the product anyway.
That’s why this page exists. We’re not pretending every batch is perfect. We’re showing you the ones that weren’t, exactly what went wrong, and what we did about it. Because our passing COAs only mean something if the system actually catches failures. This page proves it does.
We’d love to have a perfect record. A 100% pass rate would mean we never eat the cost of a failed batch, never have awkward conversations with suppliers, and never have to publish a page like this one. But a perfect record from a company that runs 10-panel testing across multiple suppliers isn’t a sign of quality. It’s a sign that something isn’t adding up.
You should expect failures. You should demand to see them published. And you should be skeptical of any company that can’t produce a single one.
Rejection Statistics
Real numbers from WhyNot Labs’ independent testing program. Updated with every new batch submission. These represent actual batches tested through Vanguard Laboratory’s 10-panel conformity protocol. Not manufacturer-provided data. Not in-house results. Not estimates.
Rejected Batches
Each entry below represents a batch that failed at least one panel of our 10-panel conformity testing protocol. Supplier identities are anonymized with codenames. Compounds are described by category only. Every detail is real. Click any entry to see the full breakdown.
REJECTED
RJ-001
Cobalt Crane · Mid-scale manufacturer
March 2026
RJ-001
Cobalt Crane · Mid-scale manufacturer
✓ Net Peptide Content
✓ Sterility
✓ Endotoxin (LAL)
✓ Heavy Metals
Full Vanguard Laboratory report for batch RJ-001. Unredacted test results showing HPLC purity at 80.72%, plus sterility, endotoxin, and heavy metals panels.
REJECTED
RJ-002
Iron Mule · Large-scale manufacturer
March 2026
RJ-002
Iron Mule · Large-scale manufacturer
✗ Sterility
✓ Purity (HPLC)
✓ Net Peptide Content
✓ Heavy Metals
Full Vanguard Laboratory report for batch RJ-002. Unredacted test results showing sterility failure (growth detected) despite 99.76% purity.
The Math Behind Cheap Peptides
Here’s the thing most people don’t want to hear: thorough testing is expensive. And the economics of budget-priced peptides make it almost impossible to do it right.
Let’s walk through the actual numbers. Take a vendor selling a 30mg research compound at $70 per vial. Sounds reasonable. Maybe even competitive. But look at what that $70 actually has to cover:
| Product cost (raw compound, manufacturing) | ~$25 |
| Credit card processing (8-12%) | $5.60 – $8.40 |
| Chargeback reserves (up to 10%) | $7.00 |
| Packaging and labeling | $2.00 – $3.00 |
| Shipping (average per unit) | $4.00 – $5.00 |
| Subtotal before testing | $43.60 – $48.40 |
| Remaining margin at $70/vial | $21.60 – $26.40 |
That looks like there’s room, right? Now add testing.
A single 10-panel conformity test through an ISO-accredited lab like Vanguard Laboratory costs $800 per batch. If the batch contains 40 vials, that’s $20 per vial in testing costs alone. And that’s only when the batch passes.
When a batch fails, the vendor eats the full $800 in testing costs plus the cost of the product they can’t sell. One failed batch at these margins wipes out the profit from the next 30-40 vials. At a 12.5% failure rate (which is what we’re actually seeing), a vendor needs to price in the cost of roughly one failure for every eight batches tested.
And this is where it gets interesting. At $70 per vial, after all other costs, there’s roughly $22-26 left. Subtract the $20 per vial for testing, and you’re looking at $2-6 of actual margin. That’s before the failed batch absorption. That’s before paying staff, rent, insurance, or marketing. That’s before profit.
The floor for running a real 10-panel testing program and absorbing failures is somewhere around $52-58 per vial in hard costs. At $70, there’s maybe $12-18 left. Not enough to run a real testing program, absorb failures, and keep the lights on.
So how do budget vendors survive? Simple arithmetic. They test less. Maybe one panel instead of ten. Maybe one vial instead of five. Maybe they skip independent labs entirely and rely on the manufacturer’s in-house COA, which is the equivalent of asking someone to grade their own homework. Or they don’t test at all and post the manufacturer’s certificate with their own logo on it.
This isn’t an accusation. It’s math. And when you’re comparing prices across vendors, you should ask what that price does and doesn’t include. A 30mg research compound from WhyNot Labs costs more than $70 because the testing alone costs more than most vendors’ entire margin.
How 10-Panel Testing Catches What Others Miss
Most vendors who test at all run one or two panels. Purity (HPLC) and maybe identity (FTIR or mass spectrometry). That tells you two things: the compound is probably what it claims to be, and it’s probably mostly pure. That’s it.
Here’s what purity-only testing can’t tell you:
- Whether the vial contains the amount of compound stated on the label (net peptide content)
- Whether the product is contaminated with bacterial endotoxins (LAL testing)
- Whether the product is sterile (14-day incubation sterility test)
- Whether heavy metals are present at dangerous levels
- Whether the entire batch is consistent, not just the one vial they tested (multi-point conformity)
If purity testing catches everything, why did batch RJ-002 on this page pass purity at 99.76% and still fail sterility? Because purity measures how much of the target compound is present. It doesn’t measure what else came along for the ride.
Here’s a side-by-side comparison of what gets tested at different vendor tiers versus what WhyNot Labs runs on every batch through our 10-panel conformity testing protocol:
| Test Panel | WhyNot Labs | Most Vendors | Budget Vendors |
|---|---|---|---|
| Purity (HPLC) | ✓ | ✓ | Maybe |
| Identity (FTIR) | ✓ | Sometimes | Rarely |
| Net Peptide Content | ✓ | Rarely | ✗ |
| Endotoxin (LAL) | ✓ | Rarely | ✗ |
| Heavy Metals | ✓ | Rarely | ✗ |
| Sterility (14-day) | ✓ | Sometimes | ✗ |
| Conformity (5 vials) | ✓ | ✗ | ✗ |
| Independent ISO Lab | ✓ | ✗ | ✗ |
| Visual Inspection | ✓ | Sometimes | Rarely |
| Published COAs | ✓ | Sometimes | If asked |
10 out of 10. Every batch. Every compound. No exceptions.
The failures documented on this page prove why this matters. RJ-001 failed on purity at 80.72%, nearly 20% below the 98% threshold. A purity-only test would have caught that one. RJ-002 is the scarier case. It passed purity at 99.76% with content overfilled above label claim. Without sterility testing, that batch would be on a shelf somewhere right now, looking perfect on paper.
What This Means For Your Research
Every failed batch on this page is a batch that didn’t reach you. That’s the point.
When you see a passing COA in our COA Library, it means something specific: that batch survived a 10-panel gauntlet at an ISO-accredited lab, and the vendor publishing the results has a documented track record of rejecting product when it doesn’t pass. The COA isn’t decorative. It’s the end result of a process that actually catches problems.
Think of it like a background check. A background check that only verifies your name isn’t much of a background check. But one that checks criminal history, employment records, credit, references, and education? That tells you something real. Our 10-panel testing is the full background check. Most vendors are doing the name-verification version and calling it thorough.
Would you trust a background check that only looked at one thing?
We started WhyNot Labs with a simple premise: if you’re going to test, test for real. And if you’re going to publish results, publish all of them. The passes and the failures. Because the failures are what prove the system works.
This page will grow. Every time we submit a new batch for testing and it doesn’t pass, it gets documented here with full details. Every codename. Every panel result. Every dollar absorbed. We’re building a public record that you can point to and say: these people actually reject product. The Research Hub has more context on why independent testing matters and how to read a Certificate of Analysis. But this page is the receipts.
And here’s the part most companies don’t want you to think about: the size of this list relative to our passing COAs tells you something about the industry as a whole. Of 12 batches with returned results, 2 failed. That’s 16.7%. If we’re seeing a 16.7% failure rate with 10-panel testing, what’s the failure rate for vendors who only test purity? They’ll never know. And neither will you.
Frequently Asked Questions
How often do research peptide batches fail independent testing?
Based on WhyNot Labs’ testing data through March 2026, 2 out of 12 batches with returned results from 10-panel conformity testing have failed at least one panel. That’s a 16.7% rejection rate across multiple suppliers of different sizes. Industry-wide data isn’t publicly available because almost no company publishes failed results. The actual industry failure rate is likely higher when testing includes panels beyond basic purity. Most vendors only test 1-3 panels, which would have missed several of the failures documented on this page. A purity-only testing protocol would have caught one of our two rejections. Not both.
Do large, established peptide manufacturers ever fail quality testing?
Yes. WhyNot Labs has received failed test results from suppliers of every size, including large-scale manufacturers with 500+ employees that are widely referenced in research community forums as trusted sources. Manufacturing at scale introduces variability. Batch-to-batch inconsistency is a known reality in peptide synthesis regardless of a manufacturer’s reputation or production volume. RJ-002 on this page came from one of the two largest and most recommended manufacturers in the space. The question isn’t whether a supplier has ever produced a substandard batch. It’s whether the vendor buying from that supplier tests thoroughly enough to catch it before it reaches your bench.
Why don’t most peptide companies publish failed test results?
Publishing failures is bad for the illusion of perfection that most companies sell. If a company admits a batch failed, customers might question every batch they’ve already purchased. Most vendors test minimally: one vial, one or two panels, cheapest lab available. They treat testing as a marketing checkbox rather than a real quality gate. Some vendors don’t test at all and rely entirely on the manufacturer’s in-house COA, which is the equivalent of asking someone to grade their own homework. WhyNot Labs publishes failures because the passing results mean nothing if the system never catches anything. A filter that never gets dirty isn’t filtering.
What happens when a batch fails testing at WhyNot Labs?
The batch is immediately quarantined and never enters sellable inventory. Test results are documented on The Reject List with anonymized supplier details and the specific panels that triggered the failure. The supplier is contacted with the failed COA. Depending on severity, the batch is either returned to the manufacturer or destroyed. For RJ-002, the sterility failure triggered quarantine and supplier evaluation. WhyNot Labs absorbs the full cost of testing ($800 per batch) on every rejection. Failed product is never sold, discounted, relabeled, or quietly mixed into passing inventory. Full stop.
Who pays for testing when a batch fails?
WhyNot Labs absorbs 100% of the testing cost on failed batches. Each 10-panel conformity test costs $800 through Vanguard Laboratory (ISO/IEC 17025:2017, A2LA accredited). When a batch fails, that $800 produces zero revenue. It’s a pure loss that protects researchers from receiving substandard product. To date, WhyNot Labs has absorbed $1,600 in testing costs on rejected batches alone. This is a cost that most vendors at lower price points simply can’t afford to take, which is one reason thorough testing is rare at budget price points. The testing cost doesn’t go away just because the results are bad.
What are the most common reasons for batch rejection?
The most common failures WhyNot Labs has documented include purity below the 98% threshold, net peptide content significantly under label claims, and sterility or endotoxin contamination. Several of these failures would not have been caught by purity-only testing. RJ-002 on this page passed purity at 99.76%. It failed sterility, a panel that most vendors don’t run. Without those panels, that batch would be for sale somewhere right now. The failures that matter most are the ones nobody else tests for, and that’s exactly where our 10-panel protocol earns its cost.
How can researchers verify that a company actually rejects failed batches?
Ask to see their rejected results. WhyNot Labs is the only research peptide company we’re aware of that publishes failed test data alongside passing COAs. If a vendor claims a 100% pass rate, ask three questions: how many batches have you tested, how many panels per batch, and can you show me a single failure? A company that has tested dozens of batches across multiple suppliers and never documented a single failure is either extraordinarily lucky, not testing thoroughly, or not being honest about the results. We publish ours because you deserve to know what the system actually catches.
What’s the difference between a company that tests and a company that publishes failures?
Testing proves you checked. Publishing failures proves the testing actually matters. Any company can post passing COAs. Those are the easy ones. The hard, expensive part is showing the failures: admitting a supplier you work with produced substandard product, absorbing $800 in testing costs with zero revenue to show for it, and publicly documenting what went wrong. That’s the difference between testing as a marketing tool and testing as an actual quality control system. WhyNot Labs publishes both because the passes only mean something if the system genuinely catches and rejects failures. This page is that proof.
Can budget-priced peptide vendors afford to test this thoroughly?
The math makes it nearly impossible. Consider a vendor selling a 30mg research compound for $70 per vial. After product cost (~$25), credit card processing (8-12%), chargeback reserves (up to 10%), packaging ($2-3), and shipping ($4-5), there’s roughly $22-26 left per vial. A single 10-panel conformity test costs $800 per batch. Spread across 40 vials, that’s $20 per vial just for testing. If that batch fails, the vendor absorbs $800 in testing costs plus the cost of unsellable product, wiping out the profit from 30+ vials. At those margins, thorough testing is a financial impossibility. The only way budget math works is to test minimally or not at all. That’s not an accusation. It’s arithmetic.
Why does WhyNot Labs test for endotoxins, heavy metals, and sterility when most vendors don’t?
Because purity alone doesn’t tell you what else is in the vial. A compound can test at 99% purity via HPLC and still contain dangerous levels of endotoxins, heavy metal contamination, or microbial growth. Purity measures how much of the target compound is present. It doesn’t measure what else came along for the ride. Endotoxin testing (LAL), heavy metals screening, and sterility testing exist specifically to catch contamination that purity panels are blind to. WhyNot Labs tests all 10 panels because the failures documented on this page prove that purity-only testing misses real problems. RJ-002 is the clearest example: 99.76% pure, everything else passing, and still contaminated. Learn more about our full 10-panel testing protocol.
See the Full Picture
This page shows what we reject. Our COA Library shows what passes. Together, they tell the complete story.
For research use only. Not for human consumption. All products sold by WhyNot Labs are intended for laboratory and research purposes only. All testing performed by Vanguard Laboratory (ISO/IEC 17025:2017, A2LA accredited). WhyNot Labs holds no laboratory certifications. Supplier identities are anonymized to protect commercial relationships while maintaining full transparency about test outcomes.
