Head-to-head · 2026 audit

Prime Peptides vs Transition Biotech

Two top US peptide sources scored on the identical published formula: lab credibility, shipping, pricing, operating history, and transparency.

Prime Peptides
7.94/10

Prime Peptides

Transition Biotech
7.98/10

Transition Biotech

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Prime Peptides

7.94 /10

Strong

Higher score · 0.04 ahead

Transition Biotech

7.98 /10

Strong

Factor by factor

Prime PeptidesFactorTransition Biotech
  • 8.6Lab Credibilityweight 55%9.2
  • 9.0Shipping & Refundweight 20%6.0
  • 6.3Pricingweight 15%9.5
  • 3.8Operating Historyweight 5%1.8
  • 5.5Transparencyweight 5%4.0
  • 20Certificates confirmed at the lab10
  • 5Labs named on certificates1
Show as a table
Prime Peptides vs Transition Biotech score breakdown by category
CategoryPrime PeptidesTransition Biotech
Lab Credibility8.69.2
Shipping & Refund9.06.0
Pricing6.39.5
Operating History3.81.8
Transparency5.54.0
Overall7.947.98

Products both carry, price for price

Price per unit (mg unless marked) for products both Prime Peptides and Transition Biotech carry
PeptidePrime Peptidesper unitTransition Biotechper unit
BPC-157Guide →$5.50/mg$3.50/mg
TB-500Guide →$6.50/mg$4.50/mg
GHK-CuGuide →$0.60/mg$0.30/mg
IpamorelinGuide →$6.00/mg$3.50/mg
RetatrutideGuide →$5.42/mg$3.50/mg
TirzepatideGuide →$4.33/mg$1.33/mg
BPC-157 + TB-500$6.25/mg$2.75/mg
NAD+$0.14/mg$0.07/mg

How they compare: the verdict

Transition Biotech takes this matchup by a razor-thin margin, 7.98 to 7.94 on the published formula. Its biggest edge is pricing, where it scores 9.5 against Prime Peptides's 6.3.

It isn't a clean sweep. Prime Peptides actually edges ahead on shipping & refunds (9.0 vs 6.0), so if that factor matters most to you it's worth weighing.

On lab evidence, the heaviest-weighted factor, both Prime Peptides and Transition Biotech have independently verified third-party COAs, so the gap comes down to the other categories.

Across the 8 peptides both carry, Transition Biotech is cheaper per unit more often (Prime Peptides wins on 0, Transition Biotech on 8). The price-for-price table below has the detail, per mg (or per IU or mL for products sold that way).

Prime Peptides vs Transition Biotech: FAQ

Prime Peptides or Transition Biotech: which is better?

Transition Biotech takes this matchup by a razor-thin margin, 7.98 to 7.94 on the published formula. Its biggest edge is pricing, where it scores 9.5 against Prime Peptides's 6.3. It isn't a clean sweep. Prime Peptides actually edges ahead on shipping & refunds (9.0 vs 6.0), so if that factor matters most to you it's worth weighing. On lab evidence, the heaviest-weighted factor, both Prime Peptides and Transition Biotech have independently verified third-party COAs, so the gap comes down to the other categories. Across the 8 peptides both carry, Transition Biotech is cheaper per unit more often (Prime Peptides wins on 0, Transition Biotech on 8). The price-for-price table below has the detail, per mg (or per IU or mL for products sold that way).

Do Prime Peptides and Transition Biotech both use third-party testing?

Prime Peptides: independently verified third-party COAs. Transition Biotech: 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.

More comparisons

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