Sep 18, 2025 at 3:52 AM#1
Another round of testing, another disappointing result. I've been buying from PepSource for about 3 months and initially things seemed fine. Appetite suppression was decent at 0.5mg/week, had some nausea, all the normal signs.
Last month I ramped up to 2.4mg and felt... nothing. No increased suppression, no nausea, nothing. So I sent my latest batch to Janoshik.
Janoshik HPLC Results — PepSource Semaglutide 10mg:
- Report #JAN-2026-04227
- Labeled amount: 10mg
- Actual content: 4.3mg (43% of labeled)
- Purity: 94.7%
- Identity: Confirmed semaglutide
So it IS semaglutide, it's reasonably pure, but there's less than HALF of what the label says. When I thought I was injecting 2.4mg, I was actually getting about 1.03mg. No wonder the dose escalation felt like nothing.
This means all my dosing calculations for the past 3 months have been wrong. I've essentially been taking random doses because who knows if previous batches were also under-dosed.
7 2DerekSJ_a1c, paige_pharma, emma_london and 4 others
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Sep 18, 2025 at 4:08 AM#2
43% of labeled amount is atrocious. Even with generous allowances for degradation during shipping and handling, legitimate compounding pharmacies target 90-110% of label claim. Anything below 80% is a major quality failure.
A few questions SkepticalSean:
1. How was it shipped? Cold pack? Ambient?
2. How long between receiving and sending to Janoshik?
3. Was the lyophilized cake intact or did it look partially collapsed?
I ask because I want to rule out degradation vs. intentional under-filling. At 43% though, this is almost certainly under-filled at the manufacturing level, not degradation.
6 1maya_sedona, stefan_berlin, Dr.EM_Chicago and 3 others
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Sep 18, 2025 at 4:24 AM#3
Great questions:
1. Shipped with cold pack, arrived still cool
2. Received and sent to Janoshik within the same week, kept refrigerated
3. Cake looked fine, solid white, proper size
I don't think this is degradation. I think they're just putting ~4mg in a "10mg" vial to increase their margins. Semaglutide API is expensive. If they can sell a 4mg vial at a 10mg price, that's massive profit.
Last edited: Sep 18, 2025 at 10:24 AM
5 0ZaraB_AL, JakeSmashed95, NauseaFreeNow and 2 others
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Janoshik Analytical — Independent Testing
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Browse GL BiochemSep 18, 2025 at 4:40 AM#4
I've been buying PepSource sema for 5 months. SIX vials total. This explains everything. I was getting great results months 1-2 then my progress completely stalled even as I increased dose. My doctor was confused because my bloodwork showed I should be responding.
Turns out I was probably never above 1mg actual dose. I'm furious. That's over $500 spent on under-dosed product.
Has anyone else tested PepSource? I want to know if this is every batch or just recent ones.
Last edited: Sep 18, 2025 at 10:40 AM
4 24stefan_berlin, Dr.EM_Chicago, pete_RVA and 1 other
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Sep 18, 2025 at 6:06 AM#5
I tested PepSource tirzepatide back in January. Here were my results:
Janoshik HPLC — PepSource Tirzepatide 15mg:
- Labeled: 15mg
- Actual: 8.7mg (58% of labeled)
- Purity: 93.1%
So their tirz is under-dosed too, just not as badly. Starting to look like a pattern of systematic under-dosing across their product line. They're probably using 50-60% of the raw material they should be using to boost margins.
I stopped buying from them after that result and switched to a vendor from the vetted list. Night and day difference.
3 23julia.endo, JessicaM_2024, TomFromTexas
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