AssayIndex
Hypothalamic and posterior-pituitary hormones

Oxytocin

Pitocin · Syntocinon · C43H66N12O12S2 · monoisotopic 1006.4365 Da. The index holds 14 assay reports on this compound across 5 batches from 5 suppliers.

14 reports5 batchesmedian 99.57 %index spec 98.5 %
Section 1

Analytical fingerprint

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

Oxytocin has a pharmacopoeial monograph, which makes it the index's best available anchor for method validity: Ph. Eur. specifies the related-substances limits and the impurity identities, and a lab that can reproduce the monograph's separation on RG-2 has demonstrated real capability. The index publishes a monograph-comparison table on the oxytocin compound page for the three labs that supply the data. The dominant real-lot impurity is the reduced open chain.

Molecular formula
C43H66N12O12S2
Monoisotopic mass
1006.4365Da
Average mass
1007.19Da
Residues
9
Nominal retention (RG-2, 30 min)
7.92min
Retention window
0.25min
Counter-ion as usually shipped
acetate
Typical label claims
2 mg · 5 mg · 10 mg
Analytical difficulty (index scale)
0.95 — 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.

0339567901018513580 Oxytocin7.92 min · 99.57 % 7.7010.10 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 Oxytocin trace on the index reference method RG-2, constructed from this page's own numbers: the main peak carries the index median purity of 99.57 % area at the nominal retention time of 7.92 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 14 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 99.57% n=14
Interquartile range 0.51pp n=14
Minimum 98.72% n=14
Maximum 99.93% n=14
Pass rate vs spec 100.0% n=14
Median recovery vs claim 103.7% n=3
Median water 4.98% n=14
Median |mass error| 2.0ppm n=12
024692.093.094.095.096.097.098.099.0100.092.00–92.25 %: 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=097.50–97.75 %: n=097.75–98.00 %: n=098.00–98.25 %: n=098.25–98.50 %: n=098.50–98.75 %: n=198.75–99.00 %: n=299.00–99.25 %: n=099.25–99.50 %: n=299.50–99.75 %: n=399.75–100.00 %: n=6median 99.57 Purity (% area) Reports
Figure 2. Purity distribution across all 14 Oxytocin records. Dashed line is this compound's median (99.57 %); the solid vertical is the index acceptance specification for the hypothalamic and posterior-pituitary hormones class (98.5 %). 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.

98.698.999.199.399.699.8100.0ERPERP: Q1 98.81, median 98.82, Q3 99.41, n=5n=5WWBWWB: Q1 99.93, median 99.93, Q3 99.93, n=3n=3QYBQYB: Q1 99.68, median 99.77, Q3 99.85, n=2n=2FGPFGP: Q1 99.53, median 99.54, Q3 99.55, n=2n=2HomopeptideHomopeptide: Q1 99.93, median 99.93, Q3 99.93, n=2n=2 Purity (% area)
Figure 3. Oxytocin 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
open-chain (reduced disulfide, +2 Da)-0.52+2.01686%0.080.83
des-Gly9 (−57 Da)-0.30-57.02179%0.070.17
deamidated Gln4 (+1 Da)-0.22+0.98464%0.140.30
oxytocin dimer (intermolecular disulfide)+2.18+1004.42157%0.060.14
Tyr sulfoxide artefact (+16 Da)-0.28+15.99550%0.050.57

Degradation pathways

  • disulfide reduction then dimerisation
  • Gln4 deamidation — Ph. Eur. limits this specifically

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

Section 7

Quarterly coverage

QuarterReportsMedian purityRange
2024-Q10n<3—
2024-Q20n<3—
2024-Q3599.9399.93–99.93
2024-Q42n<399.53–99.55
2025-Q10n<3—
2025-Q2598.8298.72–99.46
2025-Q30n<3—
2025-Q40n<3—
2026-Q10n<3—
2026-Q22n<399.60–99.93
2026-Q30n<3—

Quarter-by-quarter detail →

Section 8

Most recent records

The 25 most recent Oxytocin records of 14.
ReportSupplierLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-041439QYBQYB-2601-V5169Janoshik2026-Q299.604.30—Supplier-supplied0PASS
AX-2026-041438QYBQYB-2601-V5169Nordanalyt2026-Q299.933.89—Supplier-supplied0PASS
AX-2025-020055ERPERP-2503-A7432Janoshik2025-Q298.824.60—Supplier-supplied1MARGINAL
AX-2025-020052ERPERP-2503-A7432Janoshik2025-Q299.415.45—Supplier-supplied1MARGINAL
AX-2025-020056ERPERP-2503-A7432Nordanalyt2025-Q298.815.01—Supplier-supplied1MARGINAL
AX-2025-020054ERPERP-2503-A7432Janoshik2025-Q298.724.96—Supplier-supplied1MARGINAL
AX-2025-020053ERPERP-2503-A7432Janoshik2025-Q299.464.8493.5Supplier-supplied1MARGINAL
AX-2025-018994FGPFGP-2406-W1827Janoshik2024-Q499.554.26—Supplier-supplied0PASS
AX-2024-004517FGPFGP-2406-W1827Janoshik2024-Q499.533.73—Supplier-supplied0PASS
AX-2024-004731HomopeptideHOMO-2405-U8504Medutest2024-Q399.935.49103.7Supplier-supplied0PASS
AX-2024-004239WWBWWB-2402-G4573Janoshik2024-Q399.936.33—Supplier-supplied0PASS
AX-2024-004241WWBWWB-2402-G4573Janoshik2024-Q399.937.06—Supplier-supplied0PASS
AX-2024-004240WWBWWB-2402-G4573Janoshik2024-Q399.936.73107.2Supplier-supplied0PASS
AX-2024-004732HomopeptideHOMO-2405-U8504VendorInvestigate2024-Q399.935.64—Buyer-sourced0PASS