Update — March 2026. Peptide Sciences has voluntarily shut down operations.
Excalibur Peptides is a fully operational US-based research peptide supplier with HPLC-verified purity, third-party COA on every batch, and same-day domestic shipping from Austin, Texas. For research and identification purposes only. Not for human consumption.
Peptide Sciences was, for nearly a decade, one of the most recognized names among US-based research peptide suppliers. Researchers cited the company in independent forums, university affiliated labs ordered through it for in-vitro work, and its public batch-level certificates of analysis set a baseline that many smaller vendors tried to copy. In March 2026 the company voluntarily ceased operations. The website went offline, customer support stopped responding, and no further orders were processed or shipped.
The closure was not the result of a recall, a contamination event, or a regulatory action against any specific compound the company sold. It was a business decision tied to the steadily tightening US regulatory environment around research peptides — heightened scrutiny of payment processing, more aggressive enforcement against vendors marketing toward human use, and rising compliance costs across the entire research supply chain. Companies that operated with marketing language adjacent to clinical claims drew the most attention; companies that maintained strict research-use-only positioning still had to absorb the same compliance overhead.
For the research community the impact is concrete. Active projects that depended on a specific Peptide Sciences batch lost both the supply line and the batch-matched certificate of analysis that any reproducible methods section requires. Laboratories that bookmarked Peptide Sciences COA pages for citation purposes lost permanent access. Researchers with open accounts and pending refunds were left without a recovery channel. The shutdown is final — there is no successor entity and no announced plan to resume operations.
That gap is what this page exists to address. The work researchers were doing with Peptide Sciences compounds is still valid, the methods are still valid, and the compounds themselves are still commercially available from other US-based suppliers. Switching vendors is straightforward, but the choice of replacement matters. The remainder of this page covers what to look for in a replacement, why Excalibur Peptides fits that profile, and how Excalibur compares to the other named US suppliers researchers most often evaluate.
Not every supplier that calls itself a Peptide Sciences alternative meets the same standard Peptide Sciences operated under. Before transferring an active research workflow to a new vendor, evaluate the replacement against the following five criteria. They are the criteria Peptide Sciences itself was measured against, and they are the criteria that determine whether the compounds you receive will produce reproducible results in your laboratory.
High performance liquid chromatography (HPLC) measures purity — the percentage of the sample that is the target peptide versus impurities, truncated sequences, and synthesis byproducts. The research-grade industry standard is 99% or higher. Mass spectrometry (MS, typically LC-MS) confirms identity — that the molecule in the vial actually matches the molecular weight of the sequence on the label. Purity without identity confirmation is meaningless, because a 99% pure sample of the wrong peptide is still the wrong peptide. Any vendor positioning itself as a Peptide Sciences alternative should publish both tests on every batch, not just spot batches or first batches.
A certificate of analysis (COA) is the lab report tying a specific batch number to specific test results. Public COAs — accessible without an account, downloadable, and indexed by batch — are the only way a researcher can verify before purchase that the lot they will receive has been tested. Marketing language about "third-party tested" without a public COA database is not verifiable. Peptide Sciences' COA database was one of the more transparent in the industry. Any replacement should match that standard.
Independent testing only means something if the testing laboratory is identified. Anonymous "third-party lab" claims cannot be audited, cannot be cross-referenced against the lab's accreditation, and cannot be challenged if results look inconsistent. Look for the lab name printed on the COA itself, not just in marketing copy. Two of the most commonly named independent labs in the US research peptide industry are Janoshik Analytical and Finnrick. The presence of a named lab on every batch report, with consistent reporting format, is a strong signal that the testing is real and ongoing.
Domestic shipping is not a luxury. International shipments of research peptides face customs delays, temperature exposure during extended transit, and the risk of seizure that interrupts experimental timelines. A US-based supplier with same-day order processing and 2–4 day domestic delivery via temperature-controlled shipping preserves the cold chain and predictability that lyophilized peptides require. Confirm that the supplier's stated shipping origin is a US address, not a US-based marketing entity drop-shipping from overseas.
This is both a regulatory and a quality signal. Suppliers that market toward human use are operating in a riskier regulatory posture and are more likely to face the same kind of payment-processor and compliance pressure that contributed to Peptide Sciences' decision to wind down. They are also more likely to cut corners on documentation that does not serve a consumer marketing audience. A supplier that maintains strict research-use-only language across every page is more likely to be operating with the documentation discipline that research workflows depend on.
Excalibur Peptides was built around the same documentation standard Peptide Sciences operated under and is structured specifically for laboratories that need a reliable, fully operational US-based supply line. Every point in the previous section is something Excalibur addresses directly.
Every batch is tested by HPLC for purity and by mass spectrometry for identity. The purity floor is 99%; batches that do not meet that threshold are not released. The COA accompanying each batch reports both the HPLC trace and the MS confirmation, with the molecular weight calculated and observed values reported side by side. This is the same testing profile a research methods section requires when citing peptide source and purity.
Excalibur's third-party analytical work is performed by Finnrick, an independent US-based analytical laboratory. The lab name is printed on every COA, the report format is consistent across batches, and the COAs are publicly accessible through the COA database without an account requirement. Researchers can verify a specific lot before purchase and archive the COA alongside their experimental records for downstream reproducibility.
Excalibur carries the same core compounds Peptide Sciences was best known for, with stock in vial sizes appropriate for in-vitro research workflows. BPC-157 (Body Protection Compound 157) is available for research into gastrointestinal and connective-tissue signaling pathways. TB-500, a Thymosin Beta-4 analog, is studied for actin-binding behavior in cellular models. GHK-Cu, the copper-binding tripeptide, is supplied as a copper complex for dermal-research and gene-expression studies. Tesamorelin, a GHRH analog, is stocked for growth-hormone-axis research. GHRP-6, a synthetic hexapeptide ghrelin receptor agonist, is available for ghrelin-pathway research. NAD+ is supplied for mitochondrial and cellular energy research. Beyond the core overlap, Excalibur carries MOTS-c, LL-37, the Wolverine Blend, and additional research compounds that broaden the catalog versus what Peptide Sciences offered in its final year.
Excalibur ships from Austin, Texas. Orders placed before the same-day cutoff ship the same business day. Domestic delivery is 2–4 business days via temperature-controlled carriers. Customer support is active and reachable at info [at] excaliburpeptides [dot] com. There are no announced operational changes, no payment-processor disruptions of the kind that contributed to Peptide Sciences' closure, and no migration in progress that would interrupt active research orders.
Every product page, every blog post, every COA, and every checkout step carries explicit research-use-only language. There are no reconstitution guides, no dosing calculators, no human-use protocols, and no testimonials describing human application. This is both a compliance posture and an internal discipline that keeps the catalog focused on what laboratories need.
Protide Pharmaceuticals and Limitless Life Nootropics are the two US-based research peptide suppliers most often named alongside Excalibur in researcher discussions about Peptide Sciences replacements. All three operate domestically, all three market for research use only, and all three publish COAs in some form. The differences are in the consistency and depth of documentation, the lab disclosure, and operational coverage.
| Criterion | Excalibur Peptides | Protide Pharmaceuticals | Limitless Life Nootropics |
|---|---|---|---|
| Operational status | Fully operational | Operational | Operational |
| HPLC on every batch | Yes | Yes | Yes |
| Mass spec on every batch | Yes | Varies by batch | Varies by batch |
| Public batch-level COA database | Yes — Finnrick verified | Yes | Yes |
| Named third-party lab on COA | Yes — Finnrick | Inconsistent | Inconsistent |
| Purity floor | 99%+ | 98%+ | 98%+ |
| US shipping origin | Austin, TX | US | US |
| Same-day processing | Yes | Yes | Varies |
| Research-use-only positioning | Strict, sitewide | Strict | Strict |
| Catalog overlap with Peptide Sciences | Full core overlap + bonus compounds | Partial | Partial |
The pattern that emerges is that all three suppliers clear the operational and basic-testing bar, but Excalibur is the one with the most consistent batch-by-batch coverage on both HPLC and mass spectrometry, the most explicit lab disclosure on every COA, and the widest catalog overlap with what Peptide Sciences carried. For a laboratory transferring an active workflow, that consistency is the relevant deciding factor.
Replacing a Peptide Sciences supply line is mechanically straightforward. Identify the compounds and vial sizes the current protocol calls for, locate the matching SKU in the Excalibur catalog, place the order, and archive the new batch COA alongside the previous Peptide Sciences COA in your experimental records. Where a methods section previously cited Peptide Sciences as the source vendor with a specific batch number, the same citation pattern applies to Excalibur — vendor name, catalog SKU, batch number, and the COA reference.
For ongoing studies where batch consistency matters, the recommended approach is to place a single larger order covering the projected experimental timeline so that all downstream work cites a single batch number with a single COA. Excalibur stocks vial sizes that support both pilot work and extended workflows, and the same-day shipping cutoff makes batch-locked ordering practical.
All Excalibur Peptides products are for in-vitro laboratory research use only. They are not for human consumption, not for veterinary use, and not for any clinical application. Buyers certify research-use-only status at checkout. Questions about specific compounds, batch availability, or COA access can be directed to info [at] excaliburpeptides [dot] com.
The Peptide Sciences wind-down did not happen in a single moment. It was the end of a multi-year compression that affected every US-based research peptide supplier to some degree, and the public timeline is worth understanding because it explains why the closure was orderly rather than abrupt and why the documentation gap it left behind is permanent rather than temporary.
Through 2024 and into 2025, payment-processor scrutiny of the research peptide industry intensified. Several large processors quietly added research peptides to their restricted-merchant categories, forcing suppliers to migrate to higher-cost specialty processors or to alternative settlement methods. Suppliers that had marketed in ways adjacent to clinical or human-use claims faced account closures with limited notice; suppliers that had maintained strict research-use-only posture still absorbed higher per-transaction costs and longer settlement cycles across the industry.
In late 2025 Peptide Sciences quietly pulled a handful of specific compound listings from its catalog without a public announcement. Researchers monitoring the catalog noticed the change first; the company did not publish a statement at the time. In January 2026 the order-acceptance pause began — checkout was disabled for new customers, then for returning customers, while existing orders continued to ship. In March 2026 the formal voluntary wind-down notice appeared on the homepage, customer-support channels were closed, and the COA database was taken offline within the following week.
For active customers the practical impact was the loss of three things at once: the supply line for any ongoing study, the batch-matched COA needed for methods-section citation, and the recovery channel for outstanding orders or refunds. No successor entity acquired the brand, the catalog, or the COA archive. The shutdown is final. Laboratories with active workflows have had to migrate to alternative US-based suppliers — which is the practical context this page exists to address.
The general guidance to "look for HPLC and a COA" is a starting point, not a finishing point. Documentation that holds up to a methods-section audit has specific, verifiable attributes, and the difference between a supplier that meets the standard and one that approximates it is visible in the format of the COA itself.
A defensible COA carries, at minimum, the unique batch number, the manufacture date, the test date, the name of the analyst or laboratory technician who ran the test, a reference to the retention sample held by the lab, the calculated molecular weight, the observed molecular weight, the HPLC purity percentage, and the named third-party analytical laboratory that performed the work. Reports missing any of these fields cannot be cross-referenced or independently re-verified, which is the operational definition of "not verifiable."
An HPLC chromatogram on a passing report shows a single dominant peak at the expected retention time for the target peptide, with integration ratios confirming that the dominant peak represents at least 99% of the total integrated area. Minor peaks should be small, well-separated, and consistent with known synthesis byproducts for that sequence. A chromatogram with multiple peaks of comparable area, drifting baselines, or unresolved shoulders on the main peak indicates a sample that has not met the research-grade purity floor and should not be released to researchers.
A passing LC-MS report shows the observed parent ion within plus or minus one dalton of the calculated molecular weight for the target sequence, with the fragmentation pattern consistent with the expected cleavage points. Identity confirmation without purity, or purity without identity, is not enough on its own. The Excalibur standard is to publish both the HPLC chromatogram and the LC-MS report on every batch, with the third-party laboratory (Finnrick) named on each report so the chain of custody is auditable end-to-end and a researcher can independently confirm the lab's existence and accreditation.
The supplier-closure problem and the storage-and-continuity problem are connected. When a study spans multiple weeks or months, the value of consistent supply is not only the avoided procurement friction — it is the ability to cite a single batch number across the entire methods section, with a single COA in the archive supporting every data point. When a supplier disappears mid-study, that single-batch citation becomes impossible to extend, and any reviewer reading the resulting paper sees a vendor-and-batch transition in the materials list.
Lyophilized research peptides should be stored on receipt at minus twenty degrees Celsius, in their original sealed vials, desiccated and protected from light. Repeated freeze-thaw cycles degrade peptide stability over time; vials should be allowed to reach room temperature before opening to avoid moisture condensation on the lyophilized cake. Cold-chain integrity in transit also matters: a supplier shipping from a US origin with same-day processing and two to four day domestic delivery preserves the cold chain in a way that international shipments routinely do not, particularly during summer transit windows or through customs holds.
For studies with a projected experimental timeline of several weeks or longer, the recommended procurement approach is a single batch-locked order covering the full projected need plus a reasonable contingency. This locks the methods-section citation to one batch number and one COA, eliminates downstream batch-to-batch variability as a confounding variable, and removes the risk that a mid-study reorder draws from a different lot with a different impurity profile or different observed mass tolerance.
The archival workflow that supports reproducibility is straightforward: download the batch COA at the time of purchase, file it alongside the order confirmation and the experimental records, and reference the batch number and COA in the methods section of any resulting publication. Excalibur's COA database is publicly accessible without an account, so researchers can retrieve archived COAs by batch number indefinitely — closing the documentation gap that the Peptide Sciences COA removal opened.
The following notes cover the core compounds most often cited from Peptide Sciences orders, with the matching Excalibur catalog reference for each. All entries are for in-vitro laboratory research use only.
BPC-157 (Body Protection Compound 157). A fifteen-amino-acid synthetic pentadecapeptide studied in connective-tissue and gastrointestinal signaling-pathway research. COA verification points: parent ion mass match to the calculated molecular weight, HPLC retention time consistent across batches, single dominant peak at 99%+ integrated area. Excalibur SKU: BPC-157, supplied in standard research vial sizes with batch-matched COA.
TB-500 (Thymosin Beta-4 fragment). Studied for actin-binding behavior and cell migration in preclinical cellular models. Verify on the COA that the observed mass matches the published TB-500 fragment sequence rather than full-length Thymosin Beta-4, as the two are sometimes confused in vendor labeling. Excalibur SKU: TB-500, available with batch-matched HPLC and LC-MS reports.
GHK-Cu (Glycyl-L-Histidyl-L-Lysine copper complex). A copper-binding tripeptide studied in dermal-research and gene-expression contexts. The COA should confirm the copper-complex stoichiometry rather than only the uncomplexed tripeptide mass. Excalibur SKU: GHK-Cu, supplied as the copper complex with batch-matched analytical reports.
Tesamorelin (GHRH analog). A growth-hormone-releasing-hormone analog studied in growth-hormone-axis research. The longer peptide sequence makes mass-spec confirmation particularly important to rule out truncated synthesis byproducts. Excalibur SKU: Tesamorelin, with full HPLC and LC-MS coverage on each batch.
GHRP-6 (Growth-Hormone-Releasing Peptide 6). A synthetic hexapeptide ghrelin-receptor agonist studied in ghrelin-pathway research. The shorter sequence simplifies mass-spec interpretation but does not reduce the need for batch-by-batch documentation. Excalibur SKU: GHRP-6, with batch-matched COA.
NAD+ (nicotinamide adenine dinucleotide). A coenzyme studied in mitochondrial and cellular-energy research. Verify on the COA that the compound is supplied as the oxidized form (NAD+) rather than the reduced form (NADH), as the two have different research applications. Excalibur SKU: NAD-Plus.
Beyond the Peptide Sciences core overlap, Excalibur carries MOTS-c (a mitochondrially encoded peptide studied in cellular-energy contexts), LL-37 (a cathelicidin-family peptide studied in antimicrobial-pathway research), and the Wolverine Blend (a BPC-157 plus TB-500 combination for researchers running parallel signaling studies). These compounds extend the catalog beyond what Peptide Sciences offered in its final year, while keeping the same documentation standard — HPLC plus LC-MS on every batch, Finnrick on every COA.
For researchers porting a previously published methods section to a new vendor, the recommended citation pattern is to retain the original Peptide Sciences batch reference for any data already collected, and to begin a new citation block from the first Excalibur batch forward. Reviewers expect to see the vendor and batch transition explicitly documented; obscuring it creates more questions than it answers. The Excalibur SKU, the batch number printed on the vial label, and the Finnrick COA reference are the three identifiers that should appear in any new methods entry, and all three are retrievable from the order confirmation or the public COA database at any later date.
No. Peptide Sciences voluntarily shut down in March 2026. The website is offline and the company is no longer accepting orders or shipments.
Excalibur Peptides is a fully operational US-based research peptide supplier with independent COA testing on every batch through a named third-party laboratory (Finnrick). The catalog covers the same core compounds Peptide Sciences was known for — BPC-157, TB-500, GHK-Cu, Tesamorelin, GHRP-6, NAD+ — plus additional research compounds. Research use only.
Yes. Every batch is tested by HPLC for purity and by LC-MS for identity, with the COA publicly accessible and the third-party lab (Finnrick) named on the report. The testing profile matches or exceeds the standard Peptide Sciences operated under.
The core Peptide Sciences catalog — BPC-157, TB-500, GHK-Cu, Tesamorelin, GHRP-6, NAD+ — is available through Excalibur. Bonus compounds including MOTS-c, LL-37, and the Wolverine Blend extend the catalog beyond what Peptide Sciences offered in its final year. All for research use only.
Same-day order processing for orders placed before the cutoff. Domestic USA delivery in 2–4 business days via temperature-controlled shipping from Austin, Texas.
All three are operational US-based suppliers with public COA databases and research-use-only positioning. Excalibur publishes batch-level HPLC and mass spectrometry results from a named third-party lab (Finnrick) on every batch. Protide and Limitless Life publish COAs but mass spectrometry coverage and lab disclosure vary by batch.
HPLC plus mass spectrometry on every batch, a public batch-level COA database, a named third-party laboratory on the COA itself, US-based shipping with same-day processing, and strict research-use-only positioning across the supplier's entire site.
Beyond the per-compound and per-batch considerations covered above, laboratories transitioning from Peptide Sciences to Excalibur Peptides should review a small number of practical workflow points that affect day-to-day procurement and downstream reproducibility. These notes are not regulatory guidance and do not constitute clinical advice; they are operational observations gathered from common questions researchers ask when porting an established methods section to a new vendor.
First, the canonical citation block in a methods section should now read: vendor name (Excalibur Peptides), catalog SKU, batch number, purity percentage as reported on the batch COA, observed mass against calculated mass as reported by the named third-party laboratory (Finnrick), and the COA reference identifier. Reviewers reading the methods section can independently retrieve the Excalibur COA from the public COA database using the batch number, which closes the verification loop without requiring the reviewer to contact the vendor directly. This is the same verification loop the Peptide Sciences COA database supported before the shutdown, and preserving it is the single most important reason to select a replacement vendor that publishes batch-level COAs publicly.
Second, for laboratories that previously placed standing orders with Peptide Sciences, Excalibur supports both one-off and recurring procurement patterns. There is no minimum order quantity for catalog SKUs, no account-tier requirement to access the public COA database, and no per-customer cap on batch-locked ordering. Laboratories planning multi-phase studies should consult the vial sizes listed on each product page and size the initial purchase to cover the projected experimental timeline plus a documented contingency margin. The same-day shipping cutoff makes contingency restocks practical without disrupting the methods-section citation, but the cleanest reproducibility pattern is still a single batch-locked order covering the entire study.
Third, on the documentation side, the Excalibur COA format is consistent across compounds and across batches. The same header fields appear on every COA — vendor name, compound name, batch number, manufacture date, test date, named third-party laboratory, calculated molecular weight, observed molecular weight, HPLC purity percentage, and the HPLC chromatogram alongside the LC-MS report. This consistency makes the COAs easy to archive in a structured way: researchers maintaining a vendor-and-batch spreadsheet alongside their lab notebook can extract the same fields from every Excalibur report without having to interpret a different layout per compound.
Fourth, communication with Excalibur is email-based through info [at] excaliburpeptides [dot] com. There is no phone line and no physical address listed on the public site; researchers with batch-specific questions, COA-retrieval requests, or catalog availability questions can reach the team by email and expect a same-business-day response in most cases. The email-only contact channel is intentional — it produces a written record of every batch-specific question and response that researchers can archive alongside the COA itself, which is more useful for downstream methods-section defense than a phone call would be.
Finally, all of the above operates inside a strict research-use-only framing. The catalog does not include reconstitution guides, dosing calculators, human-use protocols, or testimonials referencing human application. Researchers requiring any of those resources should not order from Excalibur — the site is structured for in-vitro laboratory work and identification-purpose reference standards, and the documentation set reflects that scope. For laboratories whose work fits that scope, the migration from Peptide Sciences to Excalibur is a one-to-one replacement at the documentation level and a straightforward catalog mapping at the compound level.