Head to head
ZC Labs vs Ascend Science
ZC Labs scores 91.3 of 100 against Ascend Science at 90.5, a gap narrow enough that either is defensible. ZC Labs publishes more certificates: 39 against 29.
Same rubric, same date · 68 certificates between them · 19 compounds in common
| ZC Labs 91.3/100 Rank 3 of 56 VisitCodepepindex· 10% off | Ascend Science 90.5/100 Rank 6 of 56 | |
|---|---|---|
| Score0–100 on the published rubric | 91.3 Extensively documented | 90.5 Extensively documented |
| Evidence coverageShare of scored fields sourced | 96% | 95% |
| Certificates on fileLot records this index read | 39 | 29 |
| Testing laboratory | ILS Laboratories | Kovera Labs and/or ILS Labs |
| ISO/IEC 17025 | Accredited | Accredited |
| Label accuracyMean gap, labeled vs assayed | 9.1% | 7.1% |
| Basket price% of the peer median | 40% | 83% |
| Enforcement recordActions on record | None on record | None on record |
| Discount code | pepindex | — |
Price, compound by compound
Price per milligram at each vendor’s own listed vial size. ZC Labs is cheaper on 19, Ascend Science on 0. The median column is the peer median across every vendor this index prices.
| Compound | ZC Labs | Ascend Science | Median |
|---|---|---|---|
| 5-Amino-1MQ | $0.59 | $0.90 | $2.90 |
| BPC-157 | $2.00 | $4.90 | $5.50 |
| DSIP | $2.00 | $7.00 | $7.00 |
| Epithalon | $0.68 | $3.85 | $3.92 |
| GHK-Cu | $0.14 | $0.45 | $0.59 |
| Glutathione | $0.02 | $0.04 | $0.05 |
| Ipamorelin | $2.00 | $4.90 | $6.20 |
| KPV | $2.00 | $4.55 | $5.00 |
| Melanotan I | $1.60 | $3.85 | $4.10 |
| Melanotan II | $1.60 | $3.50 | $4.00 |
| MOTS-c | $3.00 | $4.55 | $4.70 |
| NAD+ | $0.06 | $0.10 | $0.14 |
| Retatrutide | $2.90 | $5.60 | $8.00 |
| Selank | $2.00 | $4.90 | $4.50 |
| Semax | $2.00 | $4.50 | $4.10 |
| SS-31 | $3.75 | $5.25 | $5.40 |
| TB-500 | $2.75 | $4.90 | $6.20 |
| Tesamorelin | $3.55 | $6.30 | $8.00 |
| Tirzepatide | $1.90 | $4.55 | $6.75 |
Which to pick
Pick ZC Labs if
you want the stronger documentation record of the two; you want the deeper certificate history (39 lots); you want the cheaper basket overall; you buy mostly the compounds it prices lower.
Pick Ascend Science if
you prefer its catalogue or its terms; on the recorded evidence the two are close.
Questions
- Is ZC Labs or Ascend Science better?
- ZC Labs scores 91.3 of 100 against Ascend Science at 90.5, a gap narrow enough that either is defensible. ZC Labs publishes more certificates: 39 against 29. Both figures come from the same published rubric over sourced data points, and each links to the document behind it.
- Which of ZC Labs and Ascend Science is cheaper?
- Across the 19 compounds both price, ZC Labs is cheaper on 19 and Ascend Science on 0. Price per milligram is compared at each vendor's own listed vial size.
- Who tests ZC Labs and Ascend Science peptides?
- ZC Labs: ILS Laboratories. Ascend Science: Kovera Labs and/or ILS Labs. A vendor-published certificate is recorded as a claim; only an independently commissioned assay counts as corroboration.
- How many certificates do ZC Labs and Ascend Science publish?
- ZC Labs has 39 lot-level certificates on file and Ascend Science has 29. Both counts are of certificates this index located and read, not of certificates claimed.
Both records were last re-verified on 2026-08-18 and 2026-09-29. Every figure is computed from the same rubric over sourced data points; see the methodology or the full best peptide vendors ranking. Partner links are marked and cannot affect a score.