Transition Biotech vs Zeptix Labs
Two top US peptide sources scored on the identical published formula: lab credibility, shipping, pricing, operating history, and transparency.
- Transition Biotech
- 7.98/10
Transition Biotech
- Zeptix Labs
- 8.17/10
Zeptix Labs
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Factor by factor
- 9.2Lab Credibilityweight 55%8.2
- 6.0Shipping & Refundweight 20%10.0
- 9.5Pricingweight 15%8.8
- 1.8Operating Historyweight 5%1.3
- 4.0Transparencyweight 5%5.5
- 10Certificates confirmed at the lab18
- 1Labs named on certificates2
Show as a table
| Category | Transition Biotech | Zeptix Labs |
|---|---|---|
| Lab Credibility | 9.2 | 8.2 |
| Shipping & Refund | 6.0 | 10.0 |
| Pricing | 9.5 | 8.8 |
| Operating History | 1.8 | 1.3 |
| Transparency | 4.0 | 5.5 |
| Overall | 7.98 | 8.17 |
Products both carry, price for price
| Peptide | Transition Biotechper unit | Zeptix Labsper unit |
|---|---|---|
| BPC-157Guide → | $3.50/mg | $3.00/mg |
| TB-500Guide → | $4.50/mg | $9.50/mg |
| GHK-CuGuide → | $0.30/mg | $0.40/mg |
| IpamorelinGuide → | $3.50/mg | $6.00/mg |
| RetatrutideGuide → | $3.50/mg | $2.67/mg |
| TirzepatideGuide → | $1.33/mg | $3.67/mg |
| BPC-157 + TB-500 | $2.75/mg | $5.00/mg |
How they compare: the verdict
Zeptix Labs takes this matchup by a razor-thin margin, 8.17 to 7.98 on the published formula. Its biggest edge is shipping & refunds, where it scores 10.0 against Transition Biotech's 6.0.
It isn't a clean sweep. Transition Biotech actually edges ahead on lab credibility (9.2 vs 8.2), so if that factor matters most to you it's worth weighing.
On lab evidence, the heaviest-weighted factor, both Transition Biotech and Zeptix Labs have independently verified third-party COAs, so the gap comes down to the other categories.
Across the 7 peptides both carry, Transition Biotech is cheaper per unit more often (Transition Biotech wins on 5, Zeptix Labs on 2). The price-for-price table below has the detail, per mg (or per IU or mL for products sold that way).
Affiliate links: we may earn a commission if you buy. It never changes a score or rank.
Transition Biotech vs Zeptix Labs: FAQ
Transition Biotech or Zeptix Labs: which is better?
Zeptix Labs takes this matchup by a razor-thin margin, 8.17 to 7.98 on the published formula. Its biggest edge is shipping & refunds, where it scores 10.0 against Transition Biotech's 6.0. It isn't a clean sweep. Transition Biotech actually edges ahead on lab credibility (9.2 vs 8.2), so if that factor matters most to you it's worth weighing. On lab evidence, the heaviest-weighted factor, both Transition Biotech and Zeptix Labs have independently verified third-party COAs, so the gap comes down to the other categories. Across the 7 peptides both carry, Transition Biotech is cheaper per unit more often (Transition Biotech wins on 5, Zeptix Labs on 2). The price-for-price table below has the detail, per mg (or per IU or mL for products sold that way).
Do Transition Biotech and Zeptix Labs both use third-party testing?
Transition Biotech: independently verified third-party COAs. Zeptix Labs: independently verified third-party COAs.
How was this comparison scored?
Both vendors are scored on the identical published formula: lab credibility 55%, shipping 20%, pricing 15%, operating history 5%, transparency 5%. When third-party testing cannot be independently verified, a testing gate holds the score under a cap that starts at 6.0 and rises by at most 2.5 points for operating history, shipping and reviews. Neither vendor can pay to change a score.
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