WWB semaglutide stability test — 12 month update — Verified Vendors

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Apr 2024

Rochester, MN

Nov 24, 2024 at 12:39 AM#1

Most testing discussion focuses on Janoshik, but I've been using PeptideMeter Labs for my peptide analysis. They're a US-based analytical lab that offers HPLC peptide testing. Wanted to share my GGPeps semaglutide results. Tested 3 separate GGPeps semaglutide batches: Batch 1 — GGS-2025-442 (October 2025 order) - Identity: ✅ Confirmed Semaglutide - Purity (HPLC): 96.3% - Major impurity: 2.1% (likely des-amino semaglutide variant) - Minor impurities: 1.6% combined Batch 2 — GGS-2025-518 (December 2025 order) - Identity: ✅ Confirmed Semaglutide - Purity (HPLC): 97.1% - Major impurity: 1.8% - Minor impurities: 1.1% combined Batch 3 — GGS-2026-029 (February 2026 order) - Identity: ✅ Confirmed Semaglutide - Purity (HPLC): 95.8% - Major impurity: 2.4% - Minor impurities: 1.8% combined Average across 3 batches: 96.4% For reference, I've also tested QSC semaglutide at PeptideMeter — one batch came back at 95.1%. So GGPeps is performing at least comparably on sema. PeptideMeter testing costs $95/sample for the basic peptide identity + purity panel. Turnaround was 8-12 business days. They accept samples by mail. Subjective experience: I ran GGPeps sema at 0.5mg/week for 12 weeks. Lost 19 lbs with moderate appetite suppression. Consistent with expected results for pharmaceutical semaglutide at that dose. No unusual side effects beyond mild nausea in weeks 1-2. Bottom line: GGPeps semaglutide is legitimate product with purity in the mid-to-high 90s range. 🔬

11 6sarah_TO, wendy_avl, jason_paloalto and 8 others

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stefan_berlin

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Oct 2024

Berlin, DE

Nov 24, 2024 at 1:58 AM#2

Interesting to see PeptideMeter results. I wasn't familiar with them. A few questions: 1. Are they ISO accredited? 2. Do they publish their testing methodology (column type, mobile phase, gradient)? 3. Have you cross-validated by sending the same sample to both PeptideMeter and Janoshik? Not questioning your results — just want to understand the lab's credibility compared to Janoshik which has become the de facto standard in this community.

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JenMemphis

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Jan 2025

Memphis, TN

Nov 24, 2024 at 3:17 AM#3

Good questions: 1. PeptideMeter is CLIA-certified and ISO 17025 accredited for analytical chemistry, yes. 2. They use C18 reversed-phase HPLC with UV detection at 220nm. They'll send the full method details if you request them with your results. 3. I haven't done a cross-validation yet but that's a great idea. I'll send from my next order to both labs and compare. Would be fascinating to see how closely they agree. The advantage of PeptideMeter is they're US-based so shipping samples is faster and cheaper (no international postage). Turnaround is comparable to Janoshik. The slight disadvantage is they have less community history so fewer people know about them.

9 4NurseAsh_DET, BenResearch_OR, MikeKY_noInsulin and 6 others

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Sigma-Aldrich — Research-Grade Standards

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NurseLeah_Nash

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Sep 2024

Nashville, TN

Nov 24, 2024 at 4:36 AM#4

As a pharmacist, I can put these numbers in context: - Branded Ozempic (Novo Nordisk) specifies ≥95% purity in their FDA submission - Most compounding pharmacies target 90-110% of labeled potency (wider range than you'd think) - The FDA's 503B guidance requires compounded semaglutide to test between 90-110% GGPeps averaging 96.4% puts them solidly in the pharmaceutical-grade range. The 95.8% lowest result is still above the FDA's own threshold for branded product. The impurity profile is also normal. Des-amino variants and oxidized forms are expected synthesis byproducts. At <3% total, this is clean product. One thing I'd note: semaglutide is inherently harder to synthesize at ultra-high purity compared to simpler peptides because of the C18 fatty acid sidechain. Getting 96%+ consistently is genuinely impressive for any non-Novo Nordisk manufacturer. 💊

Last edited: Nov 24, 2024 at 5:36 AM

8 3Dr.KarenChen, Dr.NateNeph, PharmD_Rodriguez and 5 others

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Dr.RaviCardio

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Jan 2024

New York, NY

Nov 24, 2024 at 12:15 PM#5

How much are GGPeps sema vials running these days? Last I checked they were $35 for 5mg vials. At 0.5mg/week that's $3.50/week or about $15/month for a medication that costs $900+/month retail. Even with the $95 testing cost factored in, the value proposition is insane. I've been doing QSC sema at $22/vial but I'm intrigued by GGPeps after seeing these purity numbers. The slight premium might be worth it for arguably better sema quality.

WWB semaglutide stability test — 12 month update

Sigma-Aldrich — Research-Grade Standards

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