Dec 5, 2024 at 7:03 PM#1
I've been maintaining a spreadsheet of all community-submitted QSC testing results. Sharing the latest compilation here. ALL results below are from Janoshik unless otherwise noted. Only including consumer-submitted tests (not vendor-submitted).
## TIRZEPATIDE (56 tests compiled)
| Batch | Date Tested | Purity | Tester |
|-------|-------------|--------|--------|
| TZ-2025-0847 | May 2025 | 97.1% | User: MidwestPep |
| TZ-2025-0903 | Jun 2025 | 98.3% | User: Dr.PathRoch |
| TZ-2025-0955 | Jul 2025 | 96.2% | User: ChemCheck |
| TZ-2025-1022 | Aug 2025 | 97.8% | User: PurityPatrol |
| TZ-2025-1089 | Sep 2025 | 93.1% | User: AZResearch ⚠️ |
| TZ-2025-1105 | Oct 2025 | 98.9% | User: SoCal_Science |
| TZ-2025-1189 | Nov 2025 | 98.7% | User: Dr.PathRoch |
| TZ-2025-1204 | Dec 2025 | 97.4% | User: steve_okc |
| TZ-2026-0015 | Jan 2026 | 97.9% | User: EastCoastEndo |
| TZ-2026-0088 | Feb 2026 | 98.1% | User: PeptidePioneer88 |
*(showing 10 of 56 — full spreadsheet linked in my profile)*
Tirz Summary Stats:
- Mean: 97.3% | Median: 97.6% | Std Dev: 1.4%
- Min: 93.1% | Max: 99.2%
- Results ≥96%: 52/56 (92.9%)
## SEMAGLUTIDE (28 tests compiled)
Sema Summary Stats:
- Mean: 95.8% | Median: 96.1% | Std Dev: 1.9%
- Min: 91.4% | Max: 98.6%
- Results ≥94%: 24/28 (85.7%)
## RETATRUTIDE (8 tests compiled)
Reta Summary Stats:
- Mean: 96.1% | Median: 96.4% | Std Dev: 1.7%
- Min: 93.3% | Max: 98.2%
Key takeaway: QSC tirzepatide is their strongest product by purity. Semaglutide runs about 1.5 points lower on average. Retatrutide is still a smaller sample size but looking solid.
The one outlier (93.1% tirz) was investigated — buyer admitted the vial had been stored at room temperature for 3 months before testing. Likely degradation, not a manufacturing issue. 📊
25 20NauseaFreeNow, SteveThurs, B12Beth and 22 others
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Dec 5, 2024 at 7:51 PM#2
As someone who does data analysis professionally, I love this. A few observations:
1. The standard deviation of 1.4% on tirz is impressively tight. This suggests good manufacturing consistency.
2. 92.9% of tirz results ≥96% is a strong pass rate.
3. The sema being lower is interesting — semaglutide is a more complex molecule (39 amino acids vs tirzepatide's 39, but with a C18 fatty acid chain modification that's harder to synthesize cleanly).
One suggestion: it would be valuable to track these over time to see if there's any trend (improving or declining quality). A simple scatter plot of purity vs. date would reveal a lot.
24 19AmyNC_wife, SkepticalSean, Dr.CardioMD and 21 others
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Dec 5, 2024 at 8:39 PM#3
Great suggestion dan_philly. I actually have that chart in my spreadsheet. The short answer is: slightly improving trend over time. The earliest 2025 tests averaged about 96.5% while Q2 2026 tests average 97.8%. Small improvement but consistent. Suggests QSC is refining their synthesis process or at least maintaining quality as they scale.
No concerning downward trends at all.
23 18LindaRN_retired, tommy_boulder, hyun_seoul and 20 others
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Sigma-Aldrich — Research-Grade Standards
Certified reference materials, analytical reagents, and research-grade standards for peptide verification. Trusted by laboratories worldwide.
Shop Reference StandardsDec 5, 2024 at 9:27 PM#4
This is phenomenal community science. A few things I want to highlight for newcomers:
1. These numbers beat many compounding pharmacies. The FDA has found compounded semaglutide testing as low as 40-60% at some pharmacies. QSC's worst result (91.4% sema) still crushes that.
2. Janoshik is the gold standard for peptide testing in this community. They're an accredited Czech lab. A Janoshik HPLC result is as reliable as it gets without pharmaceutical-level validation.
3. Consumer-submitted tests are more trustworthy than vendor-submitted because the vendor can't cherry-pick their best batch. steve_okc's compilation only using consumer tests is the right methodology.
Thank you for maintaining this steve_okc. This is genuinely important harm reduction work. 🙌
22 17CryptoCarl, MariaRD, AussieAnna and 19 others
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Dec 6, 2024 at 1:56 AM#5
I appreciate the data but want to push back on one thing: we're only testing for purity and identity. We're NOT testing for:
- Endotoxin levels (bacterial contamination markers)
- Residual solvents from synthesis
- Heavy metals
- Sterility
- Particulate matter
Purity ≠ safety. A vial could be 99% pure tirzepatide and still have dangerous levels of endotoxin. I'm not saying QSC products are unsafe — I use them myself — but let's not let high purity numbers create a false sense of complete safety.
The full picture requires testing that costs $500+ per vial, which is why almost nobody does it.
21 16tony_orlando, Dr.NephBHM_UK, kim_atl_prep and 18 others
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