Has anyone dealt with moisture content analysis for lyophilized peptides?

Dr.MetabolicMD said:

Mass spectrometry confirmation for certificates of analysis: beyond HPLC purity, mass spec tells you the molecule's exact molecular weight.

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.

quinn_sf said:

Agreed, and mass spec answers a question purity does not: identity.

Thank you — that is the clearest version of this I have read, and I have read a lot of them. Sending this to two other people who asked me the same thing last week.

Dr.MetabolicMD said:

Mass spectrometry confirmation for certificates of analysis: beyond HPLC purity, mass spec tells you the molecule's exact molecular weight.

My vendor review relevant to certificates of analysis: ordered 5 times from my current compounder. Consistency has been excellent.

Shipping: Same-day local pickup
Packaging: Professional, discreet, proper labeling with lot/batch numbers
Purity: 99.2% average across orders (Janoshik verified)
Customer service: Responsive within 6 hours
Price: $146/month for semaglutide 1.7mg equivalent

NauseaFreeNow 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…

HPLC results interpretation for certificates of analysis: when you get your Janoshik report back, here's what the numbers mean:

• Purity %: Should be >97%. Below 95% is concerning.
• Retention time: Should match reference standard for the peptide
• Related substances: Degradation products should be <2% total
• Single impurity: No individual impurity should exceed 1%

My last batch: 99.6% purity, 0.0% total related substances. Clean chromatogram with single sharp peak at expected retention time. Exactly what you want to see.

Moderator note: two posts asking for a source have been merged into one. Please search the thread before asking again. Carry on.