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ForumsCOA & Analytical TestingInter-lab variability in peptide testing — July 2024 Page 2

Inter-lab variability in peptide testing — July 2024

Dr.GastroMayo Tue, Jun 24, 2025 at 1:04 AM 41 replies 1,493 viewsPage 2 of 9
TomTeleRx
Member
189
678
Feb 2025
Delaware
Jun 24, 2025 at 3:54 AM#6

Correct. If potency preservation is your priority, lyophilized is the way to go. You control the reconstitution, you know exactly when the "clock starts" on degradation, and the dry powder is resilient to shipping temperature issues.

The main advantage of pre-mixed liquid is convenience and not having to do math. For some patients, especially those uncomfortable with reconstitution, that's worth the tradeoff.

37 12pete_manc_UK, anna.melb_AU, mark_tokyo and 34 others
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RickReta_CO
Member
312
1,234
Jan 2025
Colorado
Jun 24, 2025 at 4:11 AM#7

Been using lyophilized exclusively for 18 months. Wouldn't switch. The reconstitution takes literally 3 minutes and I know my stuff is fresh. Plus I buy larger vials (10mg) and get more doses per vial, which saves money.

The only downside is that I have to buy bac water separately. Minor inconvenience.

30 0jim_asheville, matt_MKE, Dr.ReproEndo and 27 others
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Dr.PathRoch
Member
456
2,123
Jun 2024
Rochester, MN
Jun 24, 2025 at 4:28 AM#8

One more thing — if you DO go with liquid, try to use it within 28-30 days of opening if possible, even if the BUD says longer. Once you start puncturing the stopper, you introduce contamination risk in addition to the ongoing chemical degradation. Belt and suspenders approach. 🧪

3 22WendyG_ATL, SaraMom3, Dr.MetabolicMD
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