🍪 The GLP Lounge uses cookies to improve your experience, analyze traffic, and personalize content. By continuing to use this site, you agree to our Cookie Policy.
Evidence-based GLP-1 & peptide discussion since 2023
ForumsCOA & Analytical TestingSterility testing per USP <71> — need advice Page 3

Sterility testing per USP <71> — need advice

sarah_TO Fri, May 16, 2025 at 12:02 PM 13 replies 1,420 viewsPage 3 of 3
Dr.CardioMD
VIP Member
2,678
14,567
Dec 2023
Cleveland, OH
May 17, 2025 at 11:42 AM#11
jim_asheville said:
My HPLC chromatogram analysis for certificates of analysis — I sent my batch to Janoshik and here's what the results showed: Main peak retention time:…

COA red flags for certificates of analysis — here's what to look for when reviewing a Certificate of Analysis:

  • No HPLC data: If there's no chromatography graph, it's not a real COA
  • Exact 100% purity: Suspicious — real testing always shows slight variation
  • No batch number: Can't trace back to specific production
  • No endotoxin testing: For injectables, this is essential
  • Template looks like it was made in Word: Professional labs have standardized formats

I have seen fake COAs that are literally photoshopped. Always verify independently if possible.

10 8kim_atl_prep, sarah_TO, wendy_avl and 7 others
Reply Quote Save Share Report
lucas_SP_BR
Member
456
1,890
Jun 2024
São Paulo, BR
May 17, 2025 at 4:25 PM#12
CarlaRPh_TPA said:
One addition: an unstated method makes a report close to uninterpretable.

That reframing is the part I needed. I will report back once I have actually tried it.

11 9Dr.ObesityLA, NurseKim_ATL, paul_denver and 8 others
Reply Quote Save Share Report
Dr.LipidDallas
VIP Member
2,678
14,567
Dec 2023
Dallas, TX
May 17, 2025 at 9:08 PM#13
jim_asheville said:
My HPLC chromatogram analysis for certificates of analysis — I sent my batch to Janoshik and here's what the results showed: Main peak retention time:…

I tested my certificates of analysis batch through Janoshik — 98.7% purity. That's within acceptable range for compounded peptides. Turnaround was 14 business days.

The test costs ~$142 but gives you actual HPLC chromatography data plus mass spec confirmation. For the peace of mind alone, it's worth every penny. I test every new batch from a new vendor.

12 10cory_ATX, lori_vegas, Dr.PulmRoch and 9 others
Reply Quote Save Share Report

Sigma-Aldrich — Research-Grade Standards

Certified reference materials, analytical reagents, and research-grade standards for peptide verification. Trusted by laboratories worldwide.

Shop Reference Standards
BiostatsBrad
Member
456
2,345
Jul 2024
Durham, NC
May 18, 2025 at 1:51 AM#14
sarah_TO said:
I have a certificate reporting 99.2% purity and 6.1mg content on a vial sold as 5mg, and I cannot work out whether those two numbers are consistent or…

Community-verified vendors for certificates of analysis: I maintain a spreadsheet of Janoshik-verified test results submitted by community members. Across 50 submitted tests:

  • 82% tested at ≥98% purity
  • 12% tested at 95-98% purity
  • 6% tested at <95% purity (concerning)

The vendors with consistently high purity results are listed in the Vendor Directory. We update monthly based on new community submissions.

13 11james_edin, FranDenver, Dr.BariatricHTX and 10 others
Reply Quote Save Share Report
Admin
Administrator
2,456
9,812
Oct 2023
Online
May 18, 2025 at 6:34 AM#15

Moderator note: a couple of off-topic posts removed.

Last edited: May 18, 2025 at 10:34 AM
14 12PeptideSynthNJ, Dr.KarenChen, Dr.NateNeph and 11 others
Reply Quote Save Share Report

Similar Threads

HPLC vs UPLC for peptide purity — method comparison study18 replies
Mass spectrometry for peptide identity verification — ESI-MS guide7 replies
Endotoxin testing methods — LAL vs recombinant Factor C17 replies
Red flags on COAs — how to spot a fake certificate5 replies
USP reference standards for peptide verification — sourcing guide3 replies
ForumsNewTrendingMembersAccount

Log In

Forgot password?
No account? Register