The two most commonly used third-party testing labs in the peptide community are Janoshik Analytical and Finnrick Labs. I've used both extensively over the past 18 months and want to share a detailed comparison. This isn't sponsored — I paid for every test out of my own pocket. Janoshik Analytical - Location: Czech Republic - Turnaround: 5-10 business days (typically 7) - Pricing: - HPLC purity: $65 - Content (quantitative HPLC): $65 - Identity (ESI-MS): $50 - Full peptide panel (purity + content + MS): $130 - Sterility (USP <71>): $80 - Endotoxin (LAL): $50 - Shipping: You send sample to their Czech lab. International shipping ~$25-$40 from the US. - Verification: Online verification system — enter sample ID to confirm authenticity. - Method details: Published on COA. C18 column, gradient elution, 220nm detection, ~30 min run time. - Communication: Email-based. Response time 24-48 hours. Founder (Jan) is active on several forums. Finnrick Labs - Location: United States (California) - Turnaround: 7-14 business days (typically 10) - Pricing: - HPLC purity: $75 - Content (quantitative HPLC): $75 - Identity (ESI-MS): $60 - Full peptide panel: $160 - Sterility: $95 - Endotoxin: $55 - SEC (size exclusion for aggregation): $85 - Shipping: Domestic US shipping, typically $10-$15. - Verification: Certificate includes QR code linking to results page. - Method details: Also published on COA. Uses UPLC with BEH C18 1.7μm column, 220nm, ~15 min run time. - Communication: Email + phone support. Response time typically same-day during business hours. My head-to-head comparison: I sent the SAME sample to both labs from a single vial of semaglutide 5mg: | Test | Janoshik | Finnrick | |------|----------|----------| | Purity | 97.8% | 97.2% | | Content | 4.91 mg (98.2%) | 4.85 mg (97.0%) | | Identity | Confirmed (4113.5 Da) | Confirmed (4113.6 Da) | Results are consistent and within expected lab-to-lab variability. The 0.6% purity difference is likely due to Finnrick's UPLC method resolving an additional minor peak that Janoshik's HPLC method didn't separate (as discussed in the HPLC vs UPLC thread). Initial verdict: both are legitimate, competent labs. But there are meaningful differences in the details. More below.

The biggest practical difference for US-based users is shipping. Sending a sample to Czech Republic means: - International shipping cost ($25-40 vs $10-15 domestic) - Customs risk (unlikely for a tiny analytical sample, but non-zero) - Longer total turnaround (add 5-7 days for international shipping each way) - Can't ship on ice easily (important for reconstituted/liquid samples) For lyophilized powder samples, Janoshik is fine. The product is stable at room temperature and won't degrade during shipping. But for liquid compounded semaglutide from a pharmacy (already reconstituted or formulated), Finnrick's domestic location is a significant advantage. You can ship overnight on ice and be confident the sample arrives in good condition. I've used Finnrick three times. Turnaround was 8, 11, and 13 business days from receipt. Not the fastest, but reliable. Their customer service answered a method question I had within 4 hours, which was impressive. Total cost comparison for a full panel + shipping from the US: - Janoshik: $130 (test) + $35 (shipping) = $165 - Finnrick: $160 (test) + $12 (shipping) = $172 Nearly identical total cost. Finnrick is slightly more expensive on paper but the domestic shipping advantage might offset that depending on your situation.

I've been using Janoshik since 2022 — probably 25+ samples over the years. Here's why I keep going back: 1. Track record: Janoshik has been the community standard for years. Their historical database of results is enormous, which means you can compare your batch against previous batches of the same vendor. That longitudinal data is incredibly valuable. 2. Verification system: The online verification is bulletproof. Enter the sample ID, get the full results. This makes it impossible for vendors to fabricate Janoshik COAs — anyone can check. 3. Jan's forum presence: The founder actively answers questions on multiple peptide forums. He's explained his methodology, defended his results when challenged, and even re-tested samples for free when results were disputed. That level of transparency builds trust. 4. Pricing: $130 for a full panel is hard to beat. Janoshik has kept prices stable for years while most labs have raised them. Downsides: - Email communication can be slow (48 hours isn't great when you have a time-sensitive question) - International shipping adds complexity - The HPLC method uses a traditional 5μm column — effective but not cutting-edge. Finnrick's UPLC method has better resolving power. But honestly, for 90% of community testing needs, Janoshik delivers exactly what you need at a fair price with a stellar track record. If it ain't broke, don't fix it.

Respectfully disagree that Janoshik is automatically the better choice. Here's the case for Finnrick: 1. Superior analytical capability: Finnrick runs UPLC with sub-2μm particles. As discussed in the methodology thread, this provides better chromatographic resolution. Their semaglutide method detects more impurity peaks than Janoshik's HPLC method. If you want the most thorough purity assessment, Finnrick is the better lab. 2. SEC capability: Finnrick offers size exclusion chromatography for $85 — a test that Janoshik doesn't offer. SEC detects peptide aggregation, which is a real concern for stored reconstituted peptides. If you want to know whether your vial has formed dimers or oligomers over time, Finnrick is your only option among community labs. 3. Domestic advantage for liquid samples: Already covered above, but worth emphasizing. If you're testing a liquid formulation from a compounding pharmacy, domestic shipping preserves sample integrity. 4. Regulatory standing: Finnrick is a CLIA-certified laboratory operating under US regulatory oversight. Janoshik operates in Czech Republic under EU regulations. Both are legitimate, but CLIA certification carries weight if you ever need to use test results in a formal complaint or regulatory filing. 5. Customer service: Same-day email responses and phone support. When I had a question about an unexpected impurity peak, their analytical director called me personally to walk through the chromatogram. That level of service is exceptional. Downside: $30 more expensive for the basic panel, and turnaround averages 10 days vs 7. But for the analytical quality, I think it's worth it.

I've used both labs multiple times and I think the "vs" framing is the wrong way to think about it. They serve slightly different use cases: Use Janoshik when: - Testing lyophilized powder samples (shipping stability not an issue) - You want the cheapest full panel ($130 vs $160) - You want results fastest (7 days vs 10) - You want to compare against the largest historical dataset - Basic purity + content + identity is all you need Use Finnrick when: - Testing liquid/reconstituted samples (domestic shipping advantage) - You want the highest chromatographic resolution (UPLC > HPLC) - You need SEC aggregation testing - You might use the results for regulatory reporting (CLIA cert matters) - You have a complex analytical question and want phone support Use BOTH when: - Community-funded testing initiative (dual-lab validation) - High-stakes testing (vendor with safety concerns) - You want the most robust dataset possible For the community testing initiative, I'd suggest sending every sample to both labs. The dual-lab approach costs ~$290 for basic panels (vs $130 or $160 for a single lab), but the confirmatory data is worth a huge amount in terms of result credibility. If both labs agree, the result is beyond dispute.