DSIP · Research brief

DSIP for Sale — What to Check Before You Buy

Real Peptides Research TeamEditorial

Updated September 16, 20269 min read

49 WORDS

Short answer

Most researchers comparing DSIP for sale start with price per vial, which is the least informative number on the page. Delta sleep-inducing peptide (DSIP) is a nonapeptide, nine amino acids in the sequence Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu, and that short chain is cheap to synthesise badly and genuinely expensive to synthesise cleanly.

Key takeaways

DSIP is a nonapeptide with the sequence Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu and a molecular weight of approximately 848.8 g/mol, and mass spectrometry on your specific batch is the only way to confirm that identity.
HPLC purity and net peptide content are different measurements: a vial can read 99% pure and still contain counterion and residual water as a meaningful share of its total mass.
The Asp-Ala junction in DSIP makes aspartimide formation the characteristic synthesis defect, producing isomers that mass spectrometry cannot distinguish from the target.
Any listing of DSIP for sale without a batch-matched certificate of analysis should be treated as unverified material regardless of the purity percentage advertised.
Lyophilised peptide stores at −20 °C desiccated and away from light; reconstituted solution belongs at 2–8 °C and degrades with repeated freeze-thaw cycling.
DSIP is supplied strictly for laboratory research and is not an approved drug product for human or veterinary use.

We built Real Peptides around small-batch synthesis and per-batch documentation because the same gap kept appearing across this market: catalogs listing a compound with nothing published that proves identity. Our team has reviewed enough incoming analytical data to know where short peptides fail, and DSIP fails in a specific, predictable place.

Where do you find DSIP for sale, and what should you check first?

DSIP for sale is supplied by research-chemical vendors as a lyophilised (freeze-dried) powder in small vials, for laboratory research use only. Before buying, check for a batch-specific certificate of analysis showing HPLC purity alongside mass spectrometry confirming a molecular weight near 848.8 g/mol. No batch COA means no verified identity.

The common misreading is that DSIP is a sedative compound with a settled evidence base. It isn't. DSIP was first described by Monnier and Schoenenberger at the University of Bern in the 1970s, isolated from the cerebral venous blood of rabbits during electrically induced slow-wave sleep, and the literature that followed has been inconsistent enough that its physiological role is still debated. What follows covers the documentation a legitimate listing publishes, the difference between HPLC purity and net peptide content, and how the material behaves once it reaches a bench.

What a credible research listing actually documents

A credible listing publishes three things before checkout: a batch-specific certificate of analysis, the analytical methods behind it, and the storage state the vial shipped in. Anything less is a product description, not evidence.

HPLC (high-performance liquid chromatography) separates the target peptide from truncated and modified byproducts, reporting purity as a percentage of total peak area. Mass spectrometry does the other half of the job: it confirms the molecule present matches DSIP's expected mass of roughly 848.8 g/mol for the formula C35H48N10O15. A purity figure without a mass confirmation tells you the sample is clean. It does not tell you the sample is DSIP.

The batch number printed on the vial must match the batch number on the certificate. A generic, undated COA reused across every order is a marketing asset rather than an analytical record, and it is the single most common shortcut we see when evaluating listings of DSIP for sale from high-volume marketplaces.

Three more signals worth checking: whether analysis was run in-house or by an independent laboratory, whether the vial ships desiccated under an inert headspace, and whether the supplier states the salt form. Real Peptides publishes batch documentation openly through our certificate of analysis library, and the DSIP peptide listing carries its own batch record rather than a shared template.

In our experience, suppliers who resist sending a COA before purchase almost never produce a better one afterwards.

Purity on the label versus peptide in the vial

A 99% HPLC purity figure describes the proportion of peptide-related material in the sample. It does not describe how much of the vial's mass is peptide. Those are different measurements, and conflating them is the most expensive mistake in peptide procurement.

Lyophilised peptides carry counterions left over from purification, usually trifluoroacetate from reversed-phase HPLC or acetate after salt exchange, plus residual bound water that a hygroscopic powder pulls in readily. Net peptide content, determined by amino acid analysis or nitrogen determination, is the figure that tells you actual peptide mass. Most vendors never publish it. Two vials can both read 99% pure by HPLC and still differ in delivered peptide mass, which quietly distorts any concentration calculation built on the label weight alone.

Then there is DSIP's own chemistry. The sequence contains an Asp-Ala junction, and during Fmoc solid-phase peptide synthesis the repeated piperidine deprotection cycles can drive aspartimide formation at exactly that point. The resulting alpha and beta aspartyl isomers, along with epimerised D-isomer byproducts, are nearly identical in mass to the target and can co-elute on a single-gradient HPLC run. Mass spectrometry will not flag them, because the mass is the same.

That is the failure mode generic guides skip entirely. The Gly-Gly stretch earlier in the chain adds a second risk, deletion sequences, which do show up by mass. Aspartimide-derived isomers do not, which is why synthesis conditions and gradient method matter as much as the purity number itself.

Handling, storage, and what happens after delivery

Lyophilised DSIP is stable for extended periods at −20 °C when kept desiccated and protected from light. Once reconstituted with bacteriostatic water, it belongs at 2–8 °C and should be treated as a short-lived solution rather than a stock that keeps indefinitely.

One handling detail causes more silent losses than any other: opening a cold vial at room temperature. The powder is hygroscopic, ambient moisture condenses into the vial the moment the seal breaks, and that water accelerates hydrolysis long before anything looks visibly wrong. Allowing vials to equilibrate to room temperature before opening costs twenty minutes and prevents the problem entirely. Repeated freeze-thaw cycling on reconstituted solution causes a similar slow degradation, which is why aliquoting into single-use volumes is standard laboratory practice.

DSIP is also rapidly hydrolysed by serum peptidases, with the literature reporting clearance measured in minutes rather than hours. That short window shapes in vitro study design far more than most purchasing decisions account for.

On arithmetic: the certificate stating the peptide mass in the vial is the only defensible basis for mg-per-mL calculations. Label weight alone includes counterion and water mass, so it overstates concentration.

Everything sold here is research-use-only material, not approved for human or veterinary use, and anyone with a health question about an animal should speak with their veterinarian rather than sourcing research compounds. This article is educational, covering laboratory handling and supplier evaluation only.

Comparing DSIP for Sale Across Supplier Tiers

Supplier tiers differ less in price than in what they can prove. The table below maps what each tier typically documents and where that documentation breaks down.

Supplier tier	Documentation typically provided	Where it breaks down	Bottom line
Bulk marketplace or overseas reseller	Product photo, purity claim in the description, occasionally a PDF with no batch number	No traceability between the vial in your hand and any analysis; repackaging history unknown	Lowest price per milligram, highest chance the material is not what the listing says. Unsuitable for any work you intend to publish.
General research-chemical catalog	Shared COA template covering a product line rather than a batch, in-house HPLC only	Purity figure may be genuine but is not tied to your lot; no mass spec and no net peptide content	Acceptable for rough screening, inadequate when identity or concentration accuracy matters to the result.
Small-batch specialist supplier	Batch-specific COA with HPLC chromatogram and mass spectrometry, stated salt form, documented storage state	Costs more per milligram and batch sizes are limited	The defensible choice for reproducible work. You can trace a result back to a specific synthesis run.
Compounding or grey-market source	Prescription-style packaging, no analytical chemistry, implied human-use framing	Misrepresents regulatory status; DSIP is not an FDA-approved drug product in any form	Avoid. The legal exposure and the analytical opacity both point the same direction.

What If: DSIP Sourcing Scenarios

These are the situations that come up most often once an order of DSIP for sale actually arrives.

What if the vial arrives warm after several days in transit?

Inspect the powder, then contact the supplier before doing anything else. Lyophilised peptide tolerates short ambient excursions far better than reconstituted solution, which is precisely why reputable suppliers ship it dry rather than pre-mixed. The relevant question is cumulative exposure, not a single warm afternoon, and a supplier who cannot tell you how the shipment was packed cannot tell you whether the material is intact.

What if the vial looks almost empty?

Don't assume you were shortchanged. A few milligrams of lyophilised nonapeptide forms a thin film or a barely visible cake at the bottom of the vial, and that appearance is entirely normal. The cake can also loosen in transit and adhere to the stopper. What matters is the mass stated on the batch certificate, not what the vial looks like under fluorescent light.

What if the COA batch number doesn't match the vial label?

Stop and request the correct document. A mismatch means the analysis in your hand describes different material, which makes every downstream number in your study unverifiable. Occasionally it is a clerical error and the supplier produces the right record within a day. Sometimes the request goes unanswered, which is its own answer.

What if reconstituted solution turns cloudy or develops particles?

Discard it rather than filtering and continuing. Cloudiness in a previously clear peptide solution indicates aggregation, microbial growth, or precipitation from a pH or temperature shift, and none of those are recoverable states. Aggregated peptide gives unreliable concentration readings even when the total mass in the tube hasn't changed.

The Unglamorous Truth About Buying DSIP

Here's the honest answer: much of the demand for DSIP is driven by claims that outrun the evidence. The original Bern research established the peptide's existence and its association with slow-wave sleep in animal models, but the decades of work since have produced inconsistent findings, and DSIP has no approved therapeutic application anywhere. Buying it expecting a settled outcome is buying a story. Buying it as a characterised research compound, with a batch certificate that proves what is in the vial, is a legitimate scientific purchase. The difference is entirely in the documentation.

More background on this compound sits on our DSIP research overview and the DSIP question archive, while the wider research peptide catalog and our facility and shipping information cover sourcing questions that apply across compounds.

DSIP for sale is one of those categories where the cheapest option and the most expensive option can look identical in a photograph, arrive in the same generic amber vial, and produce completely different data six weeks later. The chemistry is unforgiving of shortcuts at the Asp-Ala junction, and no amount of branding compensates for a synthesis run nobody analysed properly. Ask for the certificate before you pay, read the chromatogram rather than the headline percentage, and treat any supplier who cannot produce both as a supplier selling something other than peptide.

References

Peer-reviewed sources on DSIP indexed in PubMed, listed for research context. Real Peptides supplies DSIP for laboratory research use only.

Pichia pastoris secreted peptides crossing the blood-brain barrier and DSIP fusion peptide efficacy in PCPA-induced insomnia mouse models. Frontiers in pharmacology, 2024. PMID 39444618. doi:10.3389/fphar.2024.1439536
Sensing the Bactericidal and Bacteriostatic Antimicrobial Mode of Action Using Raman Deuterium Stable Isotope Probing (DSIP) in Escherichia coli. ACS omega, 2024. PMID 38854576. doi:10.1021/acsomega.4c01666
Delta Sleep-Inducing Peptide Recovers Motor Function in SD Rats after Focal Stroke. Molecules (Basel, Switzerland), 2021. PMID 34500605. doi:10.3390/molecules26175173
Effect of Delta Sleep-Inducing Peptide on Functional State of Hepatocytes in Rats During Restraint Stress. Bulletin of experimental biology and medicine, 2016. PMID 26902351. doi:10.1007/s10517-016-3186-8
Delta sleep-inducing peptide and Deltaran: potential approaches to antistress protection. Neuroscience and behavioral physiology, 2008. PMID 18975104. doi:10.1007/s11055-008-9076-4
Interaction of Delta sleep-inducing peptide and valproate on metaphit audiogenic seizure model in rats. Cellular and molecular neurobiology, 2007. PMID 17957464. doi:10.1007/s10571-007-9222-5
Delta sleep-inducing peptide (DSIP): a still unresolved riddle. Journal of neurochemistry, 2006. PMID 16539679. doi:10.1111/j.1471-4159.2006.03693.x
[Interaction of delta sleep-inducing peptide and its analogues with cellular membranes: a structure-function analysis]. Bioorganicheskaia khimiia, 2006. PMID 16637289. doi:10.1134/s1068162006020087

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Questions

Request the batch-specific certificate of analysis and confirm that the batch number on it matches the number printed on the vial you receive. The certificate should show an HPLC chromatogram with a purity percentage and a mass spectrometry result confirming a molecular weight near 848.8 g/mol. If a supplier only offers a generic PDF with no lot number, the material is effectively unverified.

DSIP (delta sleep-inducing peptide) is a nonapeptide with the sequence Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu, first described by Monnier and Schoenenberger at the University of Bern in the 1970s after isolation from the cerebral venous blood of rabbits during induced slow-wave sleep. Research since then has investigated it as a possible neuromodulator, but findings have been inconsistent and its physiological role remains debated. It has no approved therapeutic use.

Research-use-only peptides are supplied to researchers, laboratories, and institutions for in vitro and non-clinical study. They are not approved drug products and are never supplied for human or veterinary consumption. Buyers are responsible for compliance with the regulations that apply in their own jurisdiction, and anyone with a health question concerning an animal should consult a veterinarian rather than sourcing research compounds.

Price differences usually track synthesis scale and analytical rigour rather than the compound itself. Small-batch synthesis with independent HPLC and mass spectrometry on every lot costs meaningfully more per milligram than bulk material sold with a shared, undated certificate. A low price frequently reflects skipped purification steps or repackaged bulk stock of unknown origin.

Lyophilised DSIP is kept at −20 °C, desiccated and protected from light, which preserves it for extended periods. Once reconstituted with bacteriostatic water, the solution is refrigerated at 2–8 °C and treated as short-lived. Repeated freeze-thaw cycling degrades the peptide, so aliquoting into single-use volumes is standard laboratory practice.

HPLC purity reports the percentage of peptide-related material in a sample relative to total peak area, while net peptide content reports how much of the vial's actual mass is peptide. A vial can be 99% pure by HPLC and still contain trifluoroacetate or acetate counterions plus residual water as a real share of its weight. Net peptide content is determined by amino acid analysis and is rarely published, which is why concentration calculations based on label weight alone can be misleading.

No, and this is the specific weakness with this sequence. DSIP contains an Asp-Ala junction where aspartimide formation can occur during Fmoc solid-phase synthesis, producing alpha and beta aspartyl isomers with essentially the same mass as the target peptide. Mass spectrometry cannot separate them, so the HPLC gradient method and the supplier's synthesis conditions matter as much as the reported mass.

No. DSIP is not an FDA-approved drug product and has no approved medical indication. It is supplied as a research chemical for laboratory use only, and any listing that presents it in prescription-style packaging or implies human use is misrepresenting its regulatory status.

As a short nine-residue peptide, DSIP is rapidly hydrolysed by serum peptidases, with the literature describing clearance measured in minutes rather than hours. Longer or structurally stabilised peptides generally persist far longer under the same conditions. That short window is a design constraint for in vitro work, not a supplier quality issue.

Discard it rather than attempting to filter and continue. Cloudiness in a previously clear peptide solution signals aggregation, precipitation from a pH or temperature change, or microbial contamination, and none of those states are reversible. Aggregated peptide produces unreliable concentration readings even when the total mass in the vial is unchanged.

Usually not. A few milligrams of lyophilised nonapeptide forms a thin film or a small, barely visible cake, and the cake can loosen in transit and stick to the stopper. The mass stated on the batch certificate of analysis is the figure to rely on, not the visual volume in the vial.

RESEARCH USE ONLY · NOT EVALUATED BY THE FDA