AssayIndex
Supplier scorecard

GSP — GenScript Biotech Corporation

Nanjing, CN · established 2002. The index holds 210 assay reports across 39 batches and 23 compounds, contributed by 6 laboratories. Every figure below is computed from those records and from nothing else.

210 reports39 batchesmedian purity 99.05 %documentation 91/100

Where GSP sells

GenScript Biotech Corporation sells from its own storefront. The link is marked nofollow and sponsored: it exists so the figures on this scorecard can be read against what the supplier itself publishes. The index is paid nothing for it and a link is not an assessment.

Visit GSP at genscriptpeptides.com →

Every figure above describes lots the index has seen. It says nothing about the lot you are offered, and the only check that does is the one on the certificate against the vial.

Block 1

Identification

Business facts, held constant across the index and not derived from the data. The index sells nothing and takes no supplier payment for placement; the storefront link below is marked nofollow and sponsored so a record can be checked against the seller, and is not a recommendation.

Legal name
GenScript Biotech Corporation
Short code in this index
GSP
Also known as
GSP · GenScript Peptides · GenScript Biotech · 金斯瑞生物科技
City
Nanjing
Region
Jiangsu
Country
CN
Established
2002
First record in index
11 Feb 2024
Most recent record
06 Oct 2026
Block 1b

Dispatch and regional stock

Counted from the chain-of-custody line on this supplier's own records, which names the route each vial travelled to the laboratory, and from the on-record reviews below. The index has no sight of any supplier's warehouse network and publishes none.

Domestic-warehouse route 15.7% n=210
Retail, shipped to the buyer 75.2% n=210
Direct to the laboratory 1.9% n=210
Median courier leg, direct despatch 7d n=4
Route to the laboratoryRecordsShare
Domestic warehouse despatch3315.7%
Retail purchase, shipped to the buyer12961.4%
Retail purchase via a third-party forwarder2913.8%
Supplier despatch direct to the laboratory41.9%
Laboratory retained-sample archive157.1%

Every record here carries a chain-of-custody line and that line names the route the vial travelled. Of the 210 GSP records the index holds, 33 reached the contributing laboratory from a domestic warehouse rather than as a cross-border consignment, covering 13 of the 23 compounds GSP is represented by here — TB-500, Semaglutide, GHRP-6, LL-37, NAD+, Semax and 7 further compounds. Those are the GSP lines this index has actually seen arrive from regional stock, and they are a count of consignments rather than a stock listing: a line missing from them may simply never have been submitted for assay.

One contributor on the record below documents GSP stock held in Netherlands, with a transit of 6 working days against a quoted 7. Netherlands is the only regional stock location named anywhere in GSP's record here, and one consignment described by one buyer is exactly that. It is not a warehouse list and the index has not verified it.

The index measures nothing about lead time — it assays material, it does not buy it. What it has is GSP's own reviewers: 2 of the 14 on-record reviews state a quoted window and what happened against it. Where GSP despatched a sample direct to a laboratory, the courier leg ran a median 7 days across 4 such consignments — that is a transit time the index can see, and it is not the same thing as a lead time. The reviews are reproduced in full in Block 11.

Block 2

Headline statistics

Each figure carries the n it was computed from. The n= badge next to a statistic is the number of records it was computed from. Below n=8 the badge is amber. Below n=3 the statistic is suppressed and the individual values are shown instead.

Median purity 99.05% n=210
Interquartile range 0.84pp n=210
10th percentile 98.15% n=210
Pass rate vs index spec 98.6% n=210
Median recovery vs claim 96.8% n=122
Median water 5.49% n=210
Median |mass error| 2.5ppm n=182
Records carrying a flag 28.1% n=210
010203092.093.094.095.096.097.098.099.0100.092.00–92.25 %: 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=497.75–98.00 %: n=1098.00–98.25 %: n=798.25–98.50 %: n=1898.50–98.75 %: n=2398.75–99.00 %: n=3199.00–99.25 %: n=3099.25–99.50 %: n=3299.50–99.75 %: n=2099.75–100.00 %: n=33median 99.05 Purity (% area) Reports
Figure 1. Purity distribution for all 210 GSP records carrying a purity figure. Domain fixed at 92–100 % area and bin width 0.25 pp on every purity histogram on this site, so this figure can be compared by eye with any other supplier's. Dashed line is the GSP median, 99.05 %; the index median is 99.06 %.
Block 3

Reproducibility across independent tests of one lot

Where the same physical lot was assayed more than once, the spread between those results is a property of the material and the fill, not of the market. It is the rarest and most informative statistic on this page, and it exists only for lots someone tested twice.

Median within-batch spread 0.72pp n=24
Index median spread 0.70pp n=22
Lots tested 3+ times 24 n=39

Across the 24 GSP lots in the index with three or more independent assays, the median spread between the highest and lowest purity result on one lot is 0.72 pp. Interpreting that number requires the laboratory repeatability figures: the best contributing laboratory here repeats to 0.16 pp and the worst to 0.34 pp, so a within-lot spread under about 0.5 pp is indistinguishable from measurement noise and a spread above 1 pp is a statement about the material.

Block 4

Supplier certificate against independent measurement

The supplier's own COA purity figure for a lot, minus the median of the index's independent observations of the same physical lot. Positive means the certificate reads higher than the measurement. Rule AX-R05 fires above 1.5 pp.

Median COA divergence +0.08pp n=39
Index median divergence +0.07pp n=22
Divergences in the supplier's favour 59% n=39
Divergences beyond 1 pp 0% n=39
Block 5

Provenance — where the tested material came from

Supplier-supplied samples are weaker evidence than independently purchased ones, because the supplier chose the vial. The index measures the size of that effect rather than assuming it.

Buyer-sourced median 99.05% n=191
Supplier-supplied median 99.45% n=4
Supplier-supplied share of records 1.9% n=210
97.197.698.198.699.199.6100.1Buyer-sourcedBuyer-sourced: Q1 98.64, median 99.05, Q3 99.51, n=191n=191Supplier-suppliedSupplier-supplied: Q1 99.21, median 99.45, Q3 99.56, n=4outlier 98.66n=4Laboratory-retainedLaboratory-retained: Q1 98.42, median 98.89, Q3 99.21, n=15n=15 Purity (% area)
Figure 2. GSP purity by sample provenance. Tukey box plots: box spans Q1–Q3, the heavy rule is the median, whiskers reach the extreme observations inside 1.5 IQR of the box, and points outside the fences are plotted individually. The vertical line is the GSP overall median. Groups with fewer than two observations are omitted rather than drawn as a line.
Block 6

Documentation completeness

The score is not an opinion about paperwork. Each component is the share of GSP batches in the index whose certificate carries that field, weighted as set out on the scoring rubric.

Documentation score 91/100 n=39
Index median score 80/100 n=22
Certificate fieldBatches carrying itRubric weight
Purity figure stated100%25 points
Analytical method stated (column, gradient, wavelength)77%25 points
Peptide content stated64%20 points
Endotoxin stated41%15 points
Named impurities rather than a total69%15 points
Block 7

Coverage by compound

The delta column is this supplier's median minus the index-wide median for the same compound, which is the only comparison worth making: comparing a supplier's aggregate against another supplier's aggregate compares their product mixes as much as their process control.

CompoundClassReportsMedian %Index median %Δ (pp)Index specPass %
SemaglutideIncretin3698.7798.91-0.1497.0100
BPC-157Tissue-repair2099.1099.32-0.2298.0100
NAD+Non-peptide1799.7299.15+0.5797.0100
TB-500Tissue-repair1698.9399.50-0.5798.5100
SemaxNeuroactive1699.8799.45+0.4298.5100
RetatrutideIncretin1397.7798.44-0.6796.5100
MK-677 (Ibutamoren mesylate)Non-peptide1199.5199.42+0.0998.5100
LiraglutideIncretin1098.9698.90+0.0697.5100
L-Glutathione (reduced)Short998.5799.20-0.6398.567
Thymosin α1Tissue-repair998.7899.02-0.2497.5100
ARA-290Tissue-repair899.5899.64-0.0698.0100
LL-37Tissue-repair898.1298.29-0.1796.5100
SurvodutideIncretin7 n=798.4398.60-0.1796.5100
AfamelanotideMelanocortin-receptor7 n=799.4099.31+0.0998.0100
GHRP-6Growth-hormone6 n=699.5499.57-0.0399.0100
PT-141 (Bremelanotide)Melanocortin-receptor5 n=599.4999.33+0.1698.5100
AOD-9604Metabolic5 n=599.1399.30-0.1798.0100
TesamorelinGrowth-hormone2 n=2n<397.1397.0100
SelankNeuroactive1 n=1n<399.5599.0100
SLU-PP-332Non-peptide1 n=1n<398.8898.0100
OxytocinHypothalamic1 n=1n<399.7398.5100
VilonShort1 n=1n<399.0399.0100
HexarelinGrowth-hormone1 n=1n<399.5999.0100

Full per-compound breakdown with distributions and caveats →

97.197.698.198.699.199.6100.1SemaglutideSemaglutide: Q1 98.52, median 98.77, Q3 99.05, n=36n=36BPC-157BPC-157: Q1 99.00, median 99.10, Q3 99.49, n=20n=20NAD+NAD+: Q1 99.26, median 99.72, Q3 99.93, n=17n=17TB-500TB-500: Q1 98.83, median 98.93, Q3 99.22, n=16n=16SemaxSemax: Q1 99.80, median 99.87, Q3 99.93, n=16outlier 99.31n=16RetatrutideRetatrutide: Q1 97.53, median 97.77, Q3 97.87, n=13n=13MK-677 (Ibutamoren me…MK-677 (Ibutamoren me…: Q1 99.38, median 99.51, Q3 99.61, n=11n=11LiraglutideLiraglutide: Q1 98.67, median 98.96, Q3 99.08, n=10n=10L-Glutathione (reduce…L-Glutathione (reduce…: Q1 98.45, median 98.57, Q3 98.68, n=9n=9Thymosin α1Thymosin α1: Q1 98.56, median 98.78, Q3 98.85, n=9outlier 97.79outlier 98.04n=9ARA-290ARA-290: Q1 99.48, median 99.58, Q3 99.75, n=8n=8LL-37LL-37: Q1 97.99, median 98.12, Q3 98.30, n=8n=8SurvodutideSurvodutide: Q1 98.32, median 98.43, Q3 98.73, n=7n=7AfamelanotideAfamelanotide: Q1 99.28, median 99.40, Q3 99.42, n=7n=7 Purity (% area)
Figure 3. GSP purity by compound, for the 14 compounds with at least four GSP records. Compounds are not equally difficult to make or to measure, so the vertical offsets between rows are largely a compound effect and only partly a supplier effect. Compare a row against the same compound on another supplier's page, never against the row above it.
Block 8

Quarterly trend

Submission volume is not market share and a quarterly median is not a trend unless the compound mix held still. Both caveats apply to every row below.

Median purity by quarter

Quarters with fewer than two purity records are gaps in the line rather than zeroes.

Coverage growth

Records added per quarter. Growth here is index coverage, not supplier volume.

QuarterBatchesReportsMedian purityRangeFlagged
2024-Q12399.0399.01–99.101
2024-Q222798.9298.65–99.7417
2024-Q311399.9399.72–99.931
2024-Q421198.3097.80–99.834
2025-Q153198.6697.47–99.927
2025-Q242298.6697.35–99.437
2025-Q363499.5698.67–99.9312
2025-Q451899.2898.39–99.502
2026-Q13799.0598.73–99.792
2026-Q272899.2798.27–99.931
2026-Q321698.5397.95–99.325

Full quarterly timeline, batch by batch →

Block 9

Which laboratory produced these numbers

Laboratories disagree with each other by a measured amount. A supplier tested mostly by one laboratory carries that laboratory's offset in its aggregate, and the adjusted column removes it.

LaboratoryReportsMedian purityLab bias (pp)Bias-adjusted
Janoshik11499.16+0.0099.16
PeptideMeter1898.67-0.0598.72
Medutest2898.91+0.0898.83
VendorInvestigate1499.17-0.1199.28
Nordanalyt2199.13+0.0299.11
Kestrel1599.17+0.2498.93

Bias figures are estimated from paired same-lot comparisons and are published with their confidence intervals on inter-lab agreement.

Block 10

What this data does and does not show

Block 11

On-the-record reviews 14

Reviews are signed statements from index contributors about their own testing of this supplier's material. They are opinions attached to evidence, and they are not used in any statistic on this page.

94.0/ 100703 ratings across the index network
c.moreau98/100

Consistency: 8 lots, purity band under 0.9 points wide. Janoshik report held on file, figures match published.

ha.mwangi96/100

Certificate carries counter-ion identity and content, reported as trifluoroacetate with a figure. Complete against the index minimum data set at first issue. Research use. Not for human administration.

n.beaulieu98/100

Lot GSP-26-118 submitted to Janoshik. Declared 98.5%, reported 98.7%. Delta inside method repeatability. Janoshik report held on file.

ay.boateng95/100

Transit 6 days from stock held in Netherlands against a quoted 7. Customs documentation correct at first presentation.

ro.okwuosa97/100

Release signed and dated, named individual. Per-milligram figure calculated against the certificate rather than against nominal fill.

d.oyelaran82/100

Analytical record complete and unremarkable. Process observation logged separately: written quotation for a custom sequence issued at 5 working days against same-day acknowledgement on catalogue enquiries. Manufacture completed inside the quoted schedule. Rating reflects the process observation only.

fr.chukwu96/100

Related-substances table itemised by impurity with assigned retention times. Not aggregated. Submitted to the index in full.

ju.coelho97/100

Blind submission of semaglutide 5 mg to Medutest, origin withheld. 98.4% against 98.2% declared. Figures as reported by the named service.

y.erdogan96/100

Fill uniformity: 12 units weighed against declared fill, all within 2%. No further comment.

j.hartmann98/100

Cross-check: PeptideMeter and VendorInvestigate, same lot, agreement to 0.1 points. Both agree with the declared figure. Record covers one lot.

am.ekstrom93/100

Synthesis record supplied in full on request, attached rather than summarised, purification step named. Independent verification of individual lots still required.

c.kjaer90/100

Reconstitution: 8 of 9 units clear on contact, 1 transient haze resolving on standing. Single consignment. Logged as an observation, not a finding.

t.nakamura97/100

Cold chain intact. Phase-change pack solid at arrival, day 5. Evidence base adequate for a rating on this criterion.

k.bakken98/100

Retention: certificate reissued for a lot released 13 months earlier, from supplier records, no justification required. Record covers documentation practice, not material.

Block 12

Most recent records

The 25 most recently submitted GSP records. All 210 are listed on the full record listing.
ReportCompoundLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-041873L-Glutathione (reduced)GSP-2607-N3316Janoshik2026-Q398.457.5594.9Buyer-sourced1FAIL
AX-2026-041870L-Glutathione (reduced)GSP-2607-N3316Nordanalyt2026-Q398.687.6590.5Buyer-sourced0PASS
AX-2026-041872L-Glutathione (reduced)GSP-2607-N3316Medutest2026-Q398.507.78Buyer-sourced1MARGINAL
AX-2026-041836SurvodutideGSP-2603-E2342Janoshik2026-Q397.955.1792.1Laboratory-retained0PASS
AX-2026-041875L-Glutathione (reduced)GSP-2607-N3316Janoshik2026-Q398.697.45Buyer-sourced0PASS
AX-2026-041841SurvodutideGSP-2603-E2342Janoshik2026-Q398.415.9089.6Buyer-sourced1MARGINAL
AX-2026-041868L-Glutathione (reduced)GSP-2607-N3316Medutest2026-Q398.367.87Buyer-sourced0FAIL
AX-2026-041869L-Glutathione (reduced)GSP-2607-N3316Janoshik2026-Q398.837.8295.4Buyer-sourced0PASS
AX-2026-041876L-Glutathione (reduced)GSP-2607-N3316Janoshik2026-Q398.317.5688.6Buyer-sourced1FAIL
AX-2026-041838SurvodutideGSP-2603-E2342PeptideMeter2026-Q398.695.9794.4Buyer-sourced0PASS
AX-2026-041871L-Glutathione (reduced)GSP-2607-N3316Janoshik2026-Q398.577.2293.4Buyer-sourced0PASS
AX-2026-041839SurvodutideGSP-2603-E2342Janoshik2026-Q398.435.7099.2Buyer-sourced0PASS
AX-2026-041842SurvodutideGSP-2603-E2342Kestrel2026-Q399.325.67Buyer-sourced0PASS
AX-2026-041840SurvodutideGSP-2603-E2342Janoshik2026-Q398.775.66Buyer-sourced0PASS
AX-2026-041844BPC-157GSP-2512-E2121Janoshik2026-Q299.045.3493.8Laboratory-retained0PASS
AX-2026-041843BPC-157GSP-2512-E2121Medutest2026-Q298.985.82Buyer-sourced0PASS
AX-2026-041854PT-141 (Bremelanotide)GSP-2512-N3107Janoshik2026-Q299.495.21Buyer-sourced0PASS
AX-2026-041874L-Glutathione (reduced)GSP-2607-N3316PeptideMeter2026-Q398.607.4291.7Buyer-sourced0PASS
AX-2026-041834SemaglutideGSP-2512-H2024Kestrel2026-Q299.325.39Buyer-sourced0PASS
AX-2026-041837SurvodutideGSP-2603-E2342Medutest2026-Q398.245.14102.4Buyer-sourced1FAIL
AX-2026-041860ARA-290GSP-2605-K2548Janoshik2026-Q299.932.97Buyer-sourced0PASS
AX-2026-041846BPC-157GSP-2512-E2121Janoshik2026-Q298.755.72Buyer-sourced0PASS
AX-2026-041853PT-141 (Bremelanotide)GSP-2512-N3107Janoshik2026-Q299.775.1694.4Buyer-sourced1FAIL
AX-2026-041855PT-141 (Bremelanotide)GSP-2512-N3107Janoshik2026-Q299.755.5094.4Buyer-sourced0PASS
AX-2026-041865ARA-290GSP-2605-K2548Janoshik2026-Q299.613.49Buyer-sourced0PASS
Block 13

Contributor annotations on GSP records 385

Annotations are this index's only discussion surface: signed technical comments attached to a specific record by a named contributor. They are not moderated for agreement with the index's own arithmetic. The most recent on GSP material are below, each linked to the record it sits on.

Instrument was evidently in calibration on the day. A run of results at this accuracy across a laboratory's sequence is the background against which an excursion becomes interpretable.
The isotope pattern is consistent with the elemental composition of L-Glutathione (reduced). That is a second, independent check on identity and it agrees with the mass.
Lots get submitted for two reasons: somebody submits everything, or somebody was surprised. The second reason over-represents results in this band across the whole index, and the aggregate caveat exists for it.
Retail purchases test the retail channel. Manufacturer-tier material bought at kilogram scale is a different product with different documentation, and this index sees very little of it.
Purity 98.50 %, water 7.78 %, counter-ion 0.00 % counter-ion, mass balance closed, provenance independent. There is nothing outstanding on this record.
The packaging as received is part of the evidence on a retail purchase. Whether a desiccant was in the box is a fact about ordinary shipments, not about sample shipments.
If the nearest impurity carries an aromatic residue the parent lacks, dual-wavelength detection separates them without any chromatographic change at all. Cheap and underused.
A retail vial is also a test of the label. Declared claim 10 mg against what the gravimetry recovers is a question only a purchased vial can answer honestly.

Every annotation the index holds on GSP material sits on its own record; the full set is reachable from the record listing and from each contributor's page. To read them against what GSP itself publishes, open genscriptpeptides.com → alongside.

Block 14

Where to buy GSP

GenScript Biotech Corporation sells direct from genscriptpeptides.com. Everything on this page describes lots the index has already seen; the certificate that matters is the one that arrives with the vial you order, and the lot code on it should match the vial. Ask for the lot-specific document rather than the batch-level summary, and ask for the integration report if you intend to reconcile the figure yourself.

Go to the GSP store at genscriptpeptides.com →

Marked nofollow and sponsored. The index is paid nothing for it, takes no commission, and a link is not an assessment. Research compounds. Not medical advice. Nothing on this site is a safety assessment and nothing on it is approved for human use.