Head to head
Ascend Science vs ZC Labs
Ascend Science scores 88.9 of 100 against ZC Labs at 86.9. ZC Labs publishes more certificates: 39 against 29.
Same rubric, same date · 68 certificates between them · 19 compounds in common
| Ascend Science 88.9/100 Rank 5 of 57 VisitCodePEPINDEX· 15% off | ZC Labs 86.9/100 Rank 6 of 57 VisitCodepepindex· 10% off | |
|---|---|---|
| Score0–100 on the published rubric | 88.9 Extensively documented | 86.9 Extensively documented |
| Evidence coverageShare of scored fields sourced | 94% | 95% |
| Certificates on fileLot records this index read | 29 | 39 |
| Testing laboratory | Kovera Labs and/or ILS Labs | ILS Laboratories |
| ISO/IEC 17025 | Accredited | Accredited |
| Label accuracyMean gap, labeled vs assayed | 7.1% | 9.1% |
| Basket price% of the peer median | 88% | 42% |
| Enforcement recordActions on record | None on record | None on record |
| Discount code | PEPINDEX | pepindex |
Price, compound by compound
Price per milligram at each vendor’s own listed vial size. Ascend Science is cheaper on 0, ZC Labs on 19. The median column is the peer median across every vendor this index prices.
| Compound | Ascend Science | ZC Labs | Median |
|---|---|---|---|
| 5-Amino-1MQ | $0.90 | $0.59 | $3.00 |
| BPC-157 | $4.90 | $2.00 | $5.50 |
| DSIP | $7.00 | $2.00 | $7.00 |
| Epithalon | $3.85 | $0.68 | $4.00 |
| GHK-Cu | $0.45 | $0.14 | $0.59 |
| Glutathione | $0.04 | $0.02 | $0.05 |
| Ipamorelin | $4.90 | $2.00 | $6.00 |
| KPV | $4.55 | $2.00 | $5.00 |
| Melanotan I | $3.85 | $1.60 | $4.00 |
| Melanotan II | $3.50 | $1.60 | $4.00 |
| MOTS-c | $4.55 | $3.00 | $5.10 |
| NAD+ | $0.10 | $0.06 | $0.13 |
| Retatrutide | $5.60 | $2.90 | $7.70 |
| Selank | $4.90 | $2.00 | $4.35 |
| Semax | $4.50 | $2.00 | $4.00 |
| SS-31 | $5.25 | $3.75 | $5.40 |
| TB-500 | $4.90 | $2.75 | $6.10 |
| Tesamorelin | $6.30 | $3.55 | $8.00 |
| Tirzepatide | $4.55 | $1.90 | $6.50 |
Which to pick
Pick Ascend Science if
you want the stronger documentation record of the two.
Pick ZC Labs if
you want the deeper certificate history (39 lots); you want the cheaper basket overall; you buy mostly the compounds it prices lower.
Questions
- Is Ascend Science or ZC Labs better?
- Ascend Science scores 88.9 of 100 against ZC Labs at 86.9. 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 Ascend Science and ZC Labs is cheaper?
- Across the 19 compounds both price, Ascend Science is cheaper on 0 and ZC Labs on 19. Price per milligram is compared at each vendor's own listed vial size.
- Who tests Ascend Science and ZC Labs peptides?
- Ascend Science: Kovera Labs and/or ILS Labs. ZC Labs: ILS Laboratories. A vendor-published certificate is recorded as a claim; only an independently commissioned assay counts as corroboration.
- How many certificates do Ascend Science and ZC Labs publish?
- Ascend Science has 29 lot-level certificates on file and ZC Labs has 39. Both counts are of certificates this index located and read, not of certificates claimed.
Both records were last re-verified on 2026-09-29 and 2026-10-01. 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.