Jun 8, 2026 at 6:21 AM#1
Got my PeptideDetective Labs results back for GGPeps tirzepatide 10mg vials and wanted to share.
PeptideDetective Report #FNK-2026-0147
- Product: Tirzepatide 10mg lyophilized
- Vendor: GGPeps (GYC)
- Batch: GYC-TRZ-2026-0108
- Purity: 98.6%
- Grade: A ✅
- Identity confirmed via mass spectrometry
- No significant impurities detected
This is the 2nd batch I've tested from GGPeps tirz and both have been Grade A. Previous batch was 97.8%.
For those unfamiliar with PeptideDetective grading:
- Grade A: ≥97% purity, identity confirmed, no concerning impurities
- Grade B: 95-97% purity, identity confirmed
- Grade C: 90-95% purity (they recommend against use)
- Fail: <90% or identity not confirmed
Cost of test: $120 for basic purity + identity
Turnaround: 8 business days from receipt of sample
Reconstituted with 2ml BAC water, injecting 2.5mg weekly. Lost 14 lbs in 8 weeks. Appetite suppression is strong and consistent with what I experienced on brand Mounjaro.
22 0matt_MKE, Dr.ReproEndo, lucas_SP_BR and 19 others
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Jun 8, 2026 at 6:37 AM#2
Great results. I switched from brand Mounjaro to GGPeps tirz about 6 months ago when my insurance stopped covering it and I can confirm — the effects are essentially identical.
Same appetite suppression, same GI side effects (mild nausea at higher doses), same weight loss trajectory. At 98.6% purity that's not surprising — that's pharmaceutical grade.
The ONLY difference I noticed is that GGPeps tirz seems to have a slightly shorter duration of effect at the end of the week. Brand Mounjaro would last me a solid 7 days, GGPeps sometimes I notice appetite returning around day 6. Could be placebo, could be a minor formulation difference. Not a dealbreaker at all.
23 1traveltech_sara, AttorneyGrant, DebRD_ATL and 20 others
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Jun 8, 2026 at 6:54 AM#3
Thanks for posting this. I'm about to start tirzepatide and was torn between sema and tirz.
Can I ask why you went with PeptideDetective over Janoshik? Is one better than the other for tirz specifically?
24 2marcus_mpls, DeniseRN_TPA, SandraNC_45 and 21 others
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Sigma-Aldrich — Research-Grade Standards
Certified reference materials, analytical reagents, and research-grade standards for peptide verification. Trusted by laboratories worldwide.
Shop Reference StandardsJun 8, 2026 at 7:10 AM#4
Dr.EndoIndy Honestly, I went with PeptideDetective mainly because they're US-based so shipping is faster and cheaper. For testing purposes, both labs are equally reputable.
Janoshik has been around longer and has more community data, but PeptideDetective has built a solid reputation over the past couple years. Their tirzepatide testing is particularly good because they do full mass spec confirmation, which some people prefer for the more complex peptides.
As for sema vs tirz — tirzepatide has been better for me personally. The dual GIP/GLP-1 action gives better appetite suppression and I've had fewer GI side effects compared to semaglutide. But it's individual — some people do better on sema. If you can, try both and see.
Last edited: Jun 8, 2026 at 12:10 PM
25 3Dr.PeteFamMed, claudia_zurich, nancy_portland and 22 others
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Jun 8, 2026 at 8:45 AM#5
98.6% is excellent for tirzepatide. Tirz is a more complex molecule than semaglutide (39 amino acids with a C20 fatty diacid moiety), so achieving high purity is arguably more impressive.
For the science-minded: PeptideDetective's Grade A designation requires:
1. Purity ≥97% by HPLC
2. Correct molecular weight confirmed by mass spectrometry
3. Amino acid sequence confirmed
4. Endotoxin levels below USP limits
5. No single impurity >1%
Meeting all 5 criteria at 98.6% purity is a strong result. GGPeps tirz synthesis is solid.
26 4tampaLisa73, KarenAZ_mom, zoe_NC and 23 others
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