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ForumsBuyer Beware⚠ PeptideMeter exposed: some vendors scoring E grade on basic peptides

⚠ PeptideMeter exposed: some vendors scoring E grade on basic peptides

PurityPaulOR Sun, Jun 7, 2026 at 1:21 PM 4 replies 166 viewsPage 1 of 1
PurityPaulOR
Senior Member
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Mar 2024
Oregon
Jun 7, 2026 at 1:21 PM#1
Seeing a lot of confusion about PeptideMeter Analytics' vendor rating system, so let me break it down clearly. PeptideMeter uses a letter grade system (A through E) to rate vendors based on aggregated test data. Here's how it works: Grade A — Excellent (95%+ purity, accurate dosing, sterility pass) - Vendor consistently delivers pharmaceutical-grade product - Multiple passing test results across different batches - Dosing accuracy within ±10% of label claim - Only a handful of vendors achieve this rating Grade B — Good (90-95% purity, minor dosing variance) - Reliable vendor with generally good quality - May have occasional batch-to-batch variation - Dosing within ±15% of label claim - Most established vendors fall here Grade C — Acceptable (85-90% purity, moderate issues) - Product is generally what it claims to be but quality is inconsistent - Some batches may be underdosed - "Use with caution" territory Grade D — Poor (75-85% purity, significant issues) - Frequent quality problems - Underdosing common - Not recommended but not outright dangerous Grade E — Fail (<75% purity, identity failures, contamination) - Vendor has failed critical tests - Products may be mislabeled, severely underdosed, or contaminated - Avoid at all costs These grades are dynamic — they update as new test data comes in. A vendor with a B rating can move to A with more positive results, or drop to C with bad ones. 📊
28 23Dr.LeslieOBGYN, MikeNYC_runner and 25 others
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dave_SLC
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Aug 2024
Salt Lake City, UT
Jun 7, 2026 at 3:38 PM#2
This is really helpful. Where do I actually see these ratings? Is there a list on PeptideMeter's website?
27 22NicoleRaleigh, james_edin, FranDenver and 24 others
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LabKate
Senior Member
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Jan 2024
Oregon
Jun 7, 2026 at 5:55 PM#3
Yes — PeptideMeter publishes their vendor ratings on their website (peptidemeteranalytics.com) and they also share updates on their social media. They maintain a searchable database of tested vendors. You can also find their ratings mirrored in our Vendor Directory here on The GLP Lounge. The mod team updates vendor listings with the latest PeptideMeter grades whenever new results drop. Keep in mind that PeptideMeter only rates vendors they've actually tested. If a vendor isn't in their system, it doesn't mean they're bad — it just means they haven't been tested yet. Absence of data ≠ evidence of quality.
26 21Dr.SleepRoch, laura_annarbor, JenMemphis and 23 others
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anders_CPH
Senior Member
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Feb 2024
Copenhagen, DK
Jun 7, 2026 at 8:12 PM#4
Let me add some nuance that the letter grades don't capture: The rating is an aggregate. A vendor with a "B" rating might have: - 3 tests at 94-96% purity (A-level) - 1 test at 88% purity (C-level) - Average pulls them to B So always look at the individual test results behind the grade, not just the letter. A consistent B is very different from a volatile B that swings between A and D. Compound-specific variation matters too. A vendor might get: - Grade A for semaglutide - Grade C for tirzepatide - Grade B for retatrutide This could mean their sema synthesis/sourcing is excellent but their tirz is inconsistent. PeptideMeter does note compound-specific results in their detailed reports. > Don't just look at the letter — dig into the data behind it. 🔎
25 20BethLabQueen, ChrisMacros, KetoKyle and 22 others
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VanRx_Mike
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May 2024
Vancouver, CA
Jun 8, 2026 at 9:50 AM#5
How does PeptideMeter decide which vendors to test? Do they take requests?
24 19mike_mod, SarahChen_PharmD, sarah.morrison and 21 others
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