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: LabRatLisa | | 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: LabRatLisa | | TZ-2025-1204 | Dec 2025 | 97.4% | User: DataDrivenDave | | 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. 📊

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.

Great suggestion Steve. 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 Q1 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.

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. Dave's compilation only using consumer tests is the right methodology. Thank you for maintaining this Dave. This is genuinely important harm reduction work. 🙌

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.