AssayIndex
Tissue-repair and immunomodulatory peptides

KPV

Lys-Pro-Val · α-MSH (11-13) · C16H30N4O4 · monoisotopic 342.2267 Da. The index holds 94 assay reports on this compound across 12 batches from 10 suppliers.

94 reports12 batchesmedian 99.21 %index spec 99.0 %
Section 1

Analytical fingerprint

Hand-authored chemistry. These properties describe the substance and do not change when a record is added.

A tripeptide. Elutes at 5.24 min, barely retained, and that is the practical problem: on gradients starting at 5 % B, KPV partially co-elutes with the injection front and several submitted reports have integrated solvent into the main peak. RG-2's 2-min hold at 2 % B was added specifically for compounds in this retention class. Purity is routinely 99 %+ and does not discriminate; the informative number for KPV is water content, which runs high (7–12 %) because the lyophilised cake is hygroscopic.

Molecular formula
C16H30N4O4
Monoisotopic mass
342.2267Da
Average mass
342.44Da
Residues
3
Nominal retention (RG-2, 30 min)
5.24min
Retention window
0.20min
Counter-ion as usually shipped
acetate
Typical label claims
5 mg · 10 mg · 20 mg
Analytical difficulty (index scale)
0.75 — straightforward
Purity is a defined quantity
YES
Section 2

Representative chromatogram

Drawn from this page's own medians. Not a scan, not an illustration, and not any single report.

05112102251533720450 KPV5.24 min · 99.21 % 4.80 same trace · ×200 vertical expansion, baseline-corrected · main peak off-scale reporting threshold 0.05 % area 05101520253035 Retention time (min) Response (mAU)
Figure 1. A representative KPV trace on the index reference method RG-2, constructed from this page's own numbers: the main peak carries the index median purity of 99.21 % area at the nominal retention time of 5.24 min, and each impurity peak carries the median area the index has observed for that named species at its characteristic retention offset. It is not a scan of any single report — every individual record's own chromatogram is on its own page. The lower panel is the same trace at a stated vertical expansion, baseline-corrected, so the impurities are visible; the main peak runs off-scale there by design. Baseline noise is seeded from the compound slug.
Section 3

What the index has observed

Arithmetic over the 94 records the index holds. Aggregates on this page are computed over the records the index holds, which are not a random sample of the material on the market. Lots that get tested are lots someone chose to test. Read every figure here as a description of this dataset rather than as an estimate of a population.

Median purity 99.21% n=94
Interquartile range 1.10pp n=94
Minimum 97.44% n=94
Maximum 99.93% n=94
Pass rate vs spec 58.5% n=94
Median recovery vs claim 97.8% n=54
Median water 4.54% n=94
Median |mass error| 2.5ppm n=82
07142192.093.094.095.096.097.098.099.0100.092.00–92.25 %: n=092.25–92.50 %: n=092.50–92.75 %: n=092.75–93.00 %: n=093.00–93.25 %: n=093.25–93.50 %: n=093.50–93.75 %: n=093.75–94.00 %: n=094.00–94.25 %: n=094.25–94.50 %: n=094.50–94.75 %: n=094.75–95.00 %: n=095.00–95.25 %: n=095.25–95.50 %: n=095.50–95.75 %: n=095.75–96.00 %: n=096.00–96.25 %: n=096.25–96.50 %: n=096.50–96.75 %: n=096.75–97.00 %: n=097.00–97.25 %: n=097.25–97.50 %: n=297.50–97.75 %: n=197.75–98.00 %: n=298.00–98.25 %: n=498.25–98.50 %: n=798.50–98.75 %: n=1598.75–99.00 %: n=899.00–99.25 %: n=1099.25–99.50 %: n=1099.50–99.75 %: n=1199.75–100.00 %: n=24median 99.21 Purity (% area) Reports
Figure 2. Purity distribution across all 94 KPV records. Dashed line is this compound's median (99.21 %); the solid vertical is the index acceptance specification for the tissue-repair and immunomodulatory peptides class (99.0 %). Domain is fixed at 92–100 % on every purity histogram on this site so that compounds can be compared by eye — a wide distribution here is a hard compound, a narrow one is an easy one, and neither is a statement about the suppliers.
Section 4

By supplier

Suppliers with fewer than two purity records on this compound are omitted from the figure rather than drawn as a line. The full table, including the thin cells, is on the by-supplier page.

97.297.798.298.799.299.6100.1GGPepsGGPeps: Q1 98.33, median 98.61, Q3 98.77, n=24outlier 97.47outlier 99.93n=24FGPFGP: Q1 99.73, median 99.93, Q3 99.93, n=14outlier 99.33n=14HomopeptideHomopeptide: Q1 98.92, median 99.28, Q3 99.59, n=13n=13KPKP: Q1 98.89, median 99.09, Q3 99.19, n=12n=12TFCTFC: Q1 99.36, median 99.78, Q3 99.93, n=9n=9CPCCPC: Q1 98.13, median 98.26, Q3 98.59, n=9n=9MKMMKM: Q1 99.58, median 99.85, Q3 99.93, n=9n=9JEEPJEEP: Q1 99.68, median 99.77, Q3 99.85, n=2n=2 Purity (% area)
Figure 3. KPV purity by supplier, ordered by coverage. The vertical line is the index acceptance specification. Boxes that overlap are suppliers this dataset cannot separate, and most of them overlap.

Full per-supplier table with n= caveats →

Section 5

Characteristic impurities and degradants

The left three columns are authored chemistry — what this molecule characteristically carries and where it elutes. The right three are what the index has actually reported.

Named speciesΔRT (min, RG-2)Δ mass (Da)Seen inMedian % areaMax % area
acetyl-KPV (+42 Da)+0.30+42.01195%0.121.57
Lys-Pro dipeptide (−99 Da)-0.36-99.06891%0.121.26
Pro-Val dipeptide (−128 Da)-0.44-128.09586%0.121.46
diketopiperazine (−18 Da)+0.15-18.01183%0.121.22

Degradation pathways

  • diketopiperazine formation from the Lys-Pro N-terminus
  • no oxidative liability

Full impurity profile, with what each named species implies about the synthesis →

Section 7

Quarterly coverage

QuarterReportsMedian purityRange
2024-Q10n<3—
2024-Q21n<3—
2024-Q30n<3—
2024-Q40n<3—
2025-Q11599.3198.70–99.93
2025-Q23199.5897.71–99.93
2025-Q31598.6897.44–99.93
2025-Q41399.0698.63–99.48
2026-Q1999.7899.24–99.93
2026-Q21098.6197.47–98.78
2026-Q30n<3—

Quarter-by-quarter detail →

Section 8

Most recent records

The 25 most recent KPV records of 94.
ReportSupplierLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-042618GGPepsGGPE-2511-K8830Janoshik2026-Q298.625.19103.1Supplier-supplied1FAIL
AX-2026-042624GGPepsGGPE-2511-K8830Nordanalyt2026-Q298.144.2590.1Buyer-sourced0FAIL
AX-2026-042619GGPepsGGPE-2511-K8830Nordanalyt2026-Q298.594.5797.5Supplier-supplied2FAIL
AX-2026-042623GGPepsGGPE-2511-K8830VendorInvestigate2026-Q297.475.07103.3Buyer-sourced1FAIL
AX-2026-042622GGPepsGGPE-2511-K8830PeptideMeter2026-Q298.625.19—Supplier-supplied1FAIL
AX-2026-042616GGPepsGGPE-2511-K8830Medutest2026-Q298.675.59—Supplier-supplied1FAIL
AX-2026-042617GGPepsGGPE-2511-K8830Janoshik2026-Q297.774.6693.1Buyer-sourced1FAIL
AX-2026-042621GGPepsGGPE-2511-K8830Janoshik2026-Q298.745.0299.7Supplier-supplied1FAIL
AX-2026-042625GGPepsGGPE-2511-K8830Medutest2026-Q298.784.69—Supplier-supplied1FAIL
AX-2026-042620GGPepsGGPE-2511-K8830Janoshik2026-Q298.404.8395.9Supplier-supplied1FAIL
AX-2026-041965TFCTFC-2508-M4888Medutest2026-Q199.932.66105.0Supplier-supplied0FAIL
AX-2026-041966TFCTFC-2508-M4888PeptideMeter2026-Q199.352.8391.6Supplier-supplied0FAIL
AX-2026-041963TFCTFC-2508-M4888Janoshik2026-Q199.852.98—Supplier-supplied0FAIL
AX-2026-041968TFCTFC-2508-M4888PeptideMeter2026-Q199.932.9588.9Supplier-supplied1MARGINAL
AX-2026-041964TFCTFC-2508-M4888Kestrel2026-Q199.362.8689.2Supplier-supplied1FAIL
AX-2026-041971TFCTFC-2508-M4888Kestrel2026-Q199.933.76—Supplier-supplied0FAIL
AX-2026-041969TFCTFC-2508-M4888PeptideMeter2026-Q199.243.21—Supplier-supplied0PASS
AX-2026-041970TFCTFC-2508-M4888Kestrel2026-Q199.643.14—Supplier-supplied0FAIL
AX-2026-041967TFCTFC-2508-M4888Medutest2026-Q199.782.5699.4Supplier-supplied0PASS
AX-2025-020636SSASSA-2507-B7861Janoshik2025-Q499.064.51106.6Supplier-supplied0FAIL
AX-2025-020452KPKP-2509-N5148Nordanalyt2025-Q498.692.22101.9Buyer-sourced2FAIL
AX-2025-020451KPKP-2509-N5148Janoshik2025-Q499.232.40—Supplier-supplied1FAIL
AX-2025-020443KPKP-2509-N5148Janoshik2025-Q499.462.0599.3Supplier-supplied1MARGINAL
AX-2025-020442KPKP-2509-N5148Janoshik2025-Q499.182.55—Supplier-supplied1FAIL
AX-2025-020450KPKP-2509-N5148Janoshik2025-Q499.482.3289.5Supplier-supplied2FAIL