AssayIndex
Neuroactive and cognitive peptides

N-Acetyl Semax Amide

NASA · Semax amidate · N-acetyl-semax-amide · C39H54N10O10S · monoisotopic 854.3806 Da. The index holds 89 assay reports on this compound across 20 batches from 12 suppliers.

89 reports20 batchesmedian 99.26 %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.

Two modifications on the semax scaffold, and both can be individually missing, giving four possible species within 42 Da of each other. Partially-modified material is common: the index's NASA records show a mean 2.3 % combined des-acetyl and free-acid content, which is high enough that the compound's effective purity as sold is materially below its stated purity. The record page breaks out each modification state separately.

Molecular formula
C39H54N10O10S
Monoisotopic mass
854.3806Da
Average mass
854.98Da
Residues
7
Nominal retention (RG-2, 30 min)
7.62min
Retention window
0.25min
Counter-ion as usually shipped
acetate
Typical label claims
5 mg · 10 mg · 20 mg
Analytical difficulty (index scale)
0.85 — 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.

0351870351055314071 N-Acetyl Semax Amide7.62 min · 99.26 % 7.84 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 N-Acetyl Semax Amide trace on the index reference method RG-2, constructed from this page's own numbers: the main peak carries the index median purity of 99.26 % area at the nominal retention time of 7.62 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 89 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 99.26% n=89
Interquartile range 0.98pp n=89
Minimum 97.31% n=89
Maximum 99.93% n=89
Pass rate vs spec 85.4% n=89
Median recovery vs claim 97.0% n=48
Median water 8.28% n=89
Median |mass error| 2.6ppm n=77
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=497.50–97.75 %: n=197.75–98.00 %: n=498.00–98.25 %: n=298.25–98.50 %: n=298.50–98.75 %: n=998.75–99.00 %: n=1099.00–99.25 %: n=1199.25–99.50 %: n=1099.50–99.75 %: n=1399.75–100.00 %: n=23median 99.26 Purity (% area) Reports
Figure 2. Purity distribution across all 89 N-Acetyl Semax Amide records. Dashed line is this compound's median (99.26 %); the solid vertical is the index acceptance specification for the neuroactive and cognitive peptides 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.

97.197.698.198.699.199.6100.1SGNSGN: Q1 98.55, median 98.89, Q3 99.32, n=20outlier 97.31n=20HomopeptideHomopeptide: Q1 99.04, median 99.27, Q3 99.60, n=18n=18JEEPJEEP: Q1 99.86, median 99.93, Q3 99.93, n=12outlier 99.66n=12QYBQYB: Q1 99.72, median 99.90, Q3 99.93, n=10outlier 99.34n=10SWBSWB: Q1 99.10, median 99.50, Q3 99.67, n=7n=7WXTWXT: Q1 97.95, median 98.18, Q3 98.93, n=5n=5BCHBCH: Q1 97.45, median 97.47, Q3 97.54, n=4outlier 97.75n=4GGPepsGGPeps: Q1 98.59, median 98.71, Q3 98.77, n=4outlier 98.25n=4KPKP: Q1 98.38, median 98.99, Q3 99.33, n=3n=3CPCCPC: Q1 98.94, median 99.09, Q3 99.24, n=2n=2FGPFGP: Q1 99.37, median 99.49, Q3 99.61, n=2n=2TFCTFC: Q1 98.47, median 98.48, Q3 98.50, n=2n=2 Purity (% area)
Figure 3. N-Acetyl Semax Amide 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
Met sulfoxide (+16 Da)-0.34+15.99598%0.131.36
des-acetyl amide (−42 Da)-0.40-42.01192%0.120.69
semax (des-acetyl, des-amide, −41 Da)-0.56-41.02784%0.140.83
N-acetyl semax free acid (+1 Da)+0.22+0.98484%0.231.38

Degradation pathways

  • acetyl loss
  • C-terminal amide hydrolysis
  • Met oxidation

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

Section 7

Quarterly coverage

QuarterReportsMedian purityRange
2024-Q11499.2598.61–99.93
2024-Q20n<3—
2024-Q3998.5197.31–99.02
2024-Q42n<397.78–99.63
2025-Q10n<3—
2025-Q21999.7098.45–99.93
2025-Q3899.2798.81–99.73
2025-Q41899.8697.55–99.93
2026-Q1699.5298.90–99.93
2026-Q2798.9798.25–99.74
2026-Q3697.6197.44–99.39

Quarter-by-quarter detail →

Section 8

Most recent records

The 25 most recent N-Acetyl Semax Amide records of 89.
ReportSupplierLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-043368CPCCPC-2602-D2941Medutest2026-Q398.796.05102.1Supplier-supplied0PASS
AX-2026-043574BCHBCH-2602-E8253Janoshik2026-Q397.758.8597.9Supplier-supplied1FAIL
AX-2026-043575BCHBCH-2602-E8253Janoshik2026-Q397.449.19104.8Supplier-supplied1FAIL
AX-2026-043367CPCCPC-2602-D2941Nordanalyt2026-Q399.396.1692.4Supplier-supplied0PASS
AX-2026-043573BCHBCH-2602-E8253Janoshik2026-Q397.478.59—Supplier-supplied1FAIL
AX-2026-043576BCHBCH-2602-E8253Janoshik2026-Q397.469.5392.4Laboratory-retained1FAIL
AX-2026-042746GGPepsGGPE-2512-A1206PeptideMeter2026-Q298.976.67—Supplier-supplied2MARGINAL
AX-2026-042234HomopeptideHOMO-2603-C1382Janoshik2026-Q298.998.0099.6Supplier-supplied0PASS
AX-2026-042747GGPepsGGPE-2512-A1206Janoshik2026-Q298.257.00—Buyer-sourced1FAIL
AX-2026-042235HomopeptideHOMO-2603-C1382Janoshik2026-Q299.228.28—Supplier-supplied1MARGINAL
AX-2026-042233HomopeptideHOMO-2603-C1382Janoshik2026-Q299.748.0993.9Supplier-supplied0PASS
AX-2026-042745GGPepsGGPE-2512-A1206Janoshik2026-Q298.716.8792.7Supplier-supplied1MARGINAL
AX-2026-042748GGPepsGGPE-2512-A1206Janoshik2026-Q298.717.4193.3Supplier-supplied2MARGINAL
AX-2026-043229SGNSGN-2508-K1228VendorInvestigate2026-Q198.907.29106.8Buyer-sourced0PASS
AX-2026-043233SGNSGN-2508-K1228Janoshik2026-Q199.688.16—Supplier-supplied0PASS
AX-2026-043231SGNSGN-2508-K1228PeptideMeter2026-Q199.487.5799.0Supplier-supplied0PASS
AX-2026-043230SGNSGN-2508-K1228Janoshik2026-Q199.937.3393.8Supplier-supplied0PASS
AX-2026-043232SGNSGN-2508-K1228Medutest2026-Q199.207.73—Buyer-sourced0PASS
AX-2026-043228SGNSGN-2508-K1228Medutest2026-Q199.557.6294.7Supplier-supplied0PASS
AX-2026-042956KPKP-2508-D4657PeptideMeter2025-Q498.997.3497.3Supplier-supplied1FAIL
AX-2026-041837JEEPJEEP-2507-U3035Medutest2025-Q499.668.49100.1Supplier-supplied0PASS
AX-2025-019027JEEPJEEP-2507-U3035Janoshik2025-Q499.938.47—Supplier-supplied0PASS
AX-2025-019019JEEPJEEP-2507-U3035Medutest2025-Q499.938.3992.6Supplier-supplied0PASS
AX-2025-019018JEEPJEEP-2507-U3035Janoshik2025-Q499.848.4992.7Supplier-supplied0PASS
AX-2025-019022JEEPJEEP-2507-U3035Janoshik2025-Q499.849.0890.1Supplier-supplied0PASS