VIP · Research brief

Where to Buy VIP? Vial Formats, COAs and Ordering

Real Peptides Research TeamEditorial

Updated September 9, 202610 min read

60 WORDS

Short answer

VIP was first isolated from porcine duodenum in 1970 by Sami Said and Viktor Mutt, and five decades later it is still one of the more awkward neuropeptides to source cleanly. Twenty-eight amino acids long, strongly basic, highly water-soluble: straightforward to synthesise in principle, messy in practice, because every extra coupling cycle in solid-phase synthesis creates another chance for deletion…

Key takeaways

VIP is a 28-amino-acid neuropeptide that signals through the VPAC1 and VPAC2 receptors and raises intracellular cAMP.
Buy VIP only against a certificate of analysis carrying the same lot number printed on the vial you receive.
HPLC purity and net peptide content measure different things, and only net peptide content tells you how much VIP the vial actually holds.
Lyophilised VIP is hygroscopic, so the sealed vial should equilibrate to room temperature before opening and dry material should stay frozen.
Chain length and preparative HPLC losses, not branding, set the per-milligram price of a 28-residue peptide.
Research-use-only labelling is not decorative: VIP is not an FDA-approved drug product and is not supplied for human or veterinary consumption.

We synthesise in small batches and run sequence verification on every lot, so we see the analytical data before anything is packed. Here is what that keeps confirming: the number printed on a label tells you very little by itself. The lot-specific certificate of analysis sitting behind that number tells you nearly everything.

Where can you buy VIP for research?

VIP (vasoactive intestinal peptide) is supplied as a research-use-only lyophilised powder by peptide manufacturers that publish lot-specific certificates of analysis. Buy VIP only from a supplier that documents RP-HPLC purity, mass spectrometry confirmation of the roughly 3.3 kDa molecular weight, and net peptide content for the exact lot in the box.

The common misconception is that purity percentage is the whole story. It is not. A vial can read 98% pure by HPLC and still contain meaningfully less peptide by mass than the label implies, because counterion salt and residual water occupy part of that weight. What follows covers what a research vial actually holds, how to read a COA line by line, what moves the price, and how dispatch and cold-chain handling work when you buy VIP from domestic stock.

What a research vial of VIP actually contains

VIP is a 28-amino-acid neuropeptide in the secretin and glucagon superfamily. It signals through two class B G-protein-coupled receptors, VPAC1 and VPAC2, which activate adenylyl cyclase and raise intracellular cAMP (cyclic adenosine monophosphate), the second messenger that drives downstream protein kinase A activity. Research literature describes native VIP as highly labile in plasma, cleaved rapidly by peptidases, which is one reason most published work relies on in vitro systems or synthetic forms such as aviptadil, a synthetic VIP that has been investigated in clinical research.

What ships when you buy VIP is a white to off-white lyophilised (freeze-dried) powder in a sealed glass vial, typically stoppered and crimped under vacuum or inert gas. Research quantities are specified in milligrams, not grams. Labs that buy VIP in milligram amounts usually receive it as a fluffy cake or a thin film across the base of the vial rather than anything that looks substantial.

Handling follows from the chemistry. Lyophilised peptide is hygroscopic, so the sealed vial should reach room temperature before the stopper comes off, otherwise atmospheric moisture condenses straight onto the powder. Dry material is stored frozen. Once reconstituted in sterile water or a suitable buffer, the solution is aliquoted and frozen so the stock never sees repeated freeze-thaw cycles.

In our experience, more VIP is lost to condensation and careless freeze-thaw at the bench than to anything that happens in transit.

Reading the certificate of analysis before you buy VIP

A certificate of analysis is only useful when it is tied to the lot number stamped on the vial in your hand. Anyone about to buy VIP should look for six specific line items:

RP-HPLC purity, with the actual chromatogram, area percent at 220 nm and the retention time
Mass spectrometry by ESI-MS or MALDI-TOF, showing observed mass against theoretical mass for the 28-residue sequence, around 3.3 kDa
Net peptide content, meaning how much of the vial mass is peptide rather than salt and water
Counterion identity, usually trifluoroacetate from purification or acetate after salt exchange
Water content, by Karl Fischer titration or loss on drying
Sequence confirmation, plus lot number and analysis date

Here is the trap almost nobody flags. Purity and peptide content are different measurements. Purity tells you what fraction of the peptide present is the correct molecule. Peptide content tells you what fraction of the powder is peptide at all. A lot that is 98% pure with 80% net peptide content in a 1 mg vial holds roughly 0.8 mg of VIP, so a concentration calculated gravimetrically from the label weight is off by a fifth before the first pipette moves. We tell researchers who buy VIP to quantify against net peptide content, never vial weight, whenever concentration precision matters, and we publish batch data in our COA library so that number is available before ordering.

Independent verification is the other thing worth checking before you buy VIP. In-house HPLC is normal and legitimate. A named third-party analytical lab on the report is better.

What drives the price, and how ordering from stock works

Two factors dominate what you pay when you buy VIP: chain length and purification yield. Assembling 28 residues means 28 sequential coupling and deprotection cycles, each slightly below perfect efficiency, so crude purity drops as the sequence grows. Pushing that crude material to a 98% specification by preparative reverse-phase HPLC discards a real fraction of the batch. Lyophilisation, optional counterion exchange, analytical testing and insulated packaging all sit on top. A 98% specification therefore costs more per milligram than crude material, and per-milligram cost generally falls as vial size increases. Quoted prices vary widely between suppliers and shift with amino acid raw-material markets, so treat any fixed figure you see repeated online with scepticism.

Logistics is where research time actually disappears. When researchers buy VIP from domestic US stock rather than an overseas broker, orders placed on a business day dispatch within 24 hours and the vials spend days rather than weeks in transit, which is the only meaningful temperature control anyone has over a shipment. Current stock and dispatch details are listed on our stock and shipping page.

Every vial leaves labelled for research use only. VIP is not an FDA-approved drug product and is not supplied for human or veterinary consumption. This article is educational and covers laboratory handling and documentation rather than use in people or animals. If VIP is on your radar because of a pet rather than a bench project, that conversation belongs with your veterinarian, not with a research-grade vial. The same documentation standard applies across our research peptide catalog.

VIP sourcing channels compared

The channel you buy VIP through determines what documentation, traceability and recourse you get when a lot fails specification. This table sets out the four routes researchers use most often.

Sourcing channel	Documentation typically provided	Traceability and handling	Bottom line
Research peptide supplier publishing lot COAs	Lot-specific HPLC chromatogram, mass spec report, net peptide content, counterion and water content	Batch numbers trace back to one synthesis run; insulated cold-chain packing is standard	Strongest option for reproducible work, because the analytical trail matches the vial in your hand
General online marketplace reseller	Often a generic product spec sheet rather than a report for the lot actually shipped	Repackaged or drop-shipped, so the original synthesis lot is frequently untraceable	Workable only for rough screening; gravimetric concentration cannot be trusted
Overseas bulk broker	Highly variable, sometimes a certificate with no chromatogram or observed mass at all	Long ambient-temperature transit, customs holds, no meaningful cold chain	Lowest headline price and the highest risk of degraded or misidentified material
Custom synthesis house	Full analytical package, purity written to the specification you request	Made to order per project, so no shelf stock and lead times measured in weeks	Correct choice for modified analogues; slower and costlier than a catalog lot

What If: VIP sourcing and handling scenarios

What if the vial arrives warm and the gel packs have melted?

Log the arrival condition and contact the supplier before opening anything. Lyophilised VIP tolerates short ambient excursions far better than a reconstituted solution does, so brief transit warming of dry powder is not automatically disqualifying, but the decision should be documented rather than assumed. Shorter transit from domestic stock is the real control measure. Solution is the fragile form: once dissolved, a basic 28-mer faces hydrolysis and surface adsorption losses, which is why stocks are frozen in single-use aliquots.

What if the COA is a generic spec sheet instead of a lot report?

Ask for the lot-specific report and hold the order until it arrives. A generic sheet states what the product should be; a lot report states what this batch measured, complete with chromatogram, retention time and observed mass. Without it, nothing links the vial to a synthesis run, and traceability collapses the moment a result needs defending. Suppliers that index certificates by lot number treat this request as routine, so hesitation is informative. It is the fastest single filter for shortlisting where to buy VIP.

What if the vial looks empty?

Do not discard it. Milligram quantities of lyophilised peptide often present as a barely visible film on the glass instead of a visible cake, and a small fill can collapse to almost nothing during transit. Material also migrates onto the stopper, which is why a gentle tap-down or brief centrifugation before opening is standard practice. Weighing is unreliable at this scale, so reconstituting in a known volume and calculating against net peptide content on the certificate is the dependable route.

What if the observed mass does not match the theoretical mass?

Treat any deviation beyond instrument tolerance as grounds for rejection and raise it with the supplier before the material is used. For a 28-residue peptide near 3.3 kDa, a systematic offset can indicate incomplete deprotection, a retained protecting group, oxidation of the methionine residue, or a single amino acid deletion. Deletions are the dangerous case: they shift mass by exactly the missing residue and can co-elute closely enough to look acceptable on a fast gradient. Mass spectrometry catches what the chromatogram hides.

What if a supplier volunteers usage guidance with the compound?

Walk away. A vendor offering guidance on use in people or animals alongside a research compound is telling you that research-use-only labelling is decorative on that site, and that regulatory carelessness rarely stops at the label. Research peptides are supplied for laboratory investigation, not consumption. A serious supplier talks about reconstitution, storage temperature and analytics, never outcomes. The commercial incentive pushes the other way, which is exactly what makes it such a reliable filter.

The unglamorous truth about peptide sourcing

Here is the honest answer: most of the gap between suppliers is not synthesis skill, it is documentation discipline. The chemistry for a 28-mer is well established and widely available. What separates a lot you can build data on from a lot you cannot is whether somebody ran the analysis on that specific batch, published it, and will replace the vial when it misses specification. If a seller will not send a lot-specific chromatogram before you buy VIP, price comparison is meaningless. You are comparing a documented compound against an unidentified white powder.

Where you buy VIP matters less, in the end, than what you can prove about the vial afterwards. A lot number that leads back to a chromatogram, an observed mass and a net peptide figure is what makes an experiment repeatable six months later when someone asks why the numbers landed where they did. Peptide research stumbles at the documentation stage far more often than at the bench. Ask for the paperwork first and the sourcing question largely answers itself.

References

Peer-reviewed sources on VIP (Vasoactive Intestinal Peptide) indexed in PubMed, listed for research context. Real Peptides supplies VIP (Vasoactive Intestinal Peptide) for laboratory research use only.

Vasoactive Intestinal Peptide-Secreting Pheochromocytoma: A Case Report and Review of Literature. AACE clinical case reports, 2022. PMID 35959082. doi:10.1016/j.aace.2022.03.003
Vasoactive Intestinal Peptide-Secreting Tumors: A Review. Pancreas, 2019. PMID 31609932. doi:10.1097/MPA.0000000000001402
Neuronal VIP shapes intestinal stem cell activity and mucosal immunity. Cell stem cell, 2026. PMID 41795422. doi:10.1016/j.stem.2026.02.001
Nanoparticle-Driven Tendon Repair: Role of Vasoactive Intestinal Peptide in Immune Modulation and Stem Cell Enhancement. ACS nano, 2025. PMID 40184556. doi:10.1021/acsnano.4c16917
Contribution of Vasoactive Intestinal Peptide to the Depressant Effects of Glucagon-like Peptide-2 on Neurally Induced Contractile Responses in Mouse Ileal Preparations. International journal of molecular sciences, 2025. PMID 41465229. doi:10.3390/ijms262411797
Vasoactive Intestinal Peptide: A Neuropeptide that Plays an Important Role in Parkinson's Disease. Current neuropharmacology, 2025. PMID 40353414. doi:10.2174/011570159X374501250425045109
Suprachiasmatic Nucleus Vasoactive Intestinal Peptide Neurons Mediate Light-induced Transient Forgetting. Neuroscience bulletin, 2025. PMID 40670769. doi:10.1007/s12264-025-01456-7
Vasoactive Intestinal Polypeptide Secreting MS Neuroblastoma. Journal of Indian Association of Pediatric Surgeons, 2024. PMID 39691933. doi:10.4103/jiaps.jiaps_104_24

Questions

VIP is sold as a research-use-only lyophilised powder by peptide suppliers that publish lot-specific certificates of analysis. Choose a supplier that documents RP-HPLC purity, mass spectrometry confirmation of the roughly 3.3 kDa mass, net peptide content and counterion for the exact batch shipped, and that holds domestic stock for fast dispatch.

You select the vial size, confirm the lot certificate of analysis, and place the order under research-use-only terms. Orders filled from domestic stock on a business day typically dispatch within 24 hours in insulated packaging. The vial arrives as dry lyophilised powder, which is stored frozen until it is reconstituted at the bench.

Research-use-only peptides are supplied to researchers, laboratories and institutions for in vitro and preclinical laboratory investigation. They are not sold for human or veterinary consumption and are not prescription products. Requirements differ by supplier and jurisdiction, so review the vendor terms and applicable institutional rules before ordering.

Pricing varies widely by supplier, vial size, purity specification and amino acid raw-material costs, so no single figure is reliable. A 28-residue peptide costs more per milligram than a short sequence because it needs 28 coupling cycles and heavy preparative HPLC purification. Per-milligram cost usually drops as vial size increases.

The main risks are misidentified material, a deletion or truncation byproduct passing as full-length peptide, and low net peptide content that skews every calculated concentration. Long ambient-temperature transit and untraceable repackaging compound the problem. Without a lot-specific chromatogram and mass spectrometry report, none of this is detectable at the bench.

Aviptadil is a synthetic form of vasoactive intestinal peptide that has been studied in clinical research. Research-grade VIP supplied as a lyophilised powder for laboratory use is the same 28-amino-acid sequence but is not a finished drug product, is not FDA-approved, and is not supplied for use in people or animals.

HPLC purity describes what fraction of the peptide present is the correct molecule. Net peptide content describes what fraction of the powder is peptide rather than counterion salt and residual water. A vial can be 98% pure yet contain noticeably less peptide by mass than the label weight, which distorts gravimetric concentration calculations.

Dry lyophilised VIP is kept frozen in its sealed vial and allowed to reach room temperature before the stopper is removed, because the powder is hygroscopic and pulls in atmospheric moisture. After reconstitution, solutions are aliquoted into single-use volumes and frozen so the stock avoids repeated freeze-thaw cycles.

Lyophilised peptide is generally shipped in insulated packaging with cold packs rather than dry ice, because dry powder tolerates short ambient excursions far better than a solution does. The practical control is transit time, which is why domestic stock and next-business-day dispatch matter more than the coolant used.

No. Research-use-only peptides are supplied strictly for laboratory investigation, are not FDA-approved drug products, and are never intended for human or veterinary consumption. Any supplier providing usage guidance for people or pets should be treated as a red flag. Health questions about an animal belong with a veterinarian.

RESEARCH USE ONLY · NOT EVALUATED BY THE FDA