VIP (Vasoactive Intestinal Peptide): Reference Overview and Reconstitution Notes

VIP is a small signaling protein made of 28 building blocks called amino acids. It belongs to a family of similar proteins. It is studied mainly in immune system and gut research, and it is not approved by the FDA as a finished drug.

What it is

VIP (Vasoactive Intestinal Peptide) is a natural signaling protein called a neuropeptide (a chemical messenger made in nerve cells). It is built from 28 amino acids, which are the small building blocks that make up all proteins. It belongs to a large family of related signaling proteins.

The material sold for lab work is a man-made (synthetic) copy of this naturally occurring protein. The body produces VIP across the nervous system, the immune system, and the hormone-producing (endocrine) system. It acts as both a chemical messenger and a local hormone.

Research context and categorization

VIP is most often studied as a protein that sends signals in the immune system and the gut (the gastrointestinal system). Researchers also look at it in connection with the brain and the body's internal clock (the circadian rhythm, which controls sleep-wake cycles).

In lab settings, scientists study how VIP affects inflammation. Lab work shows it can reduce the amount of inflammation-triggering signals sent out by activated immune cells. Think of it like a volume knob that turns down the alarm signals those immune cells are broadcasting.

Key Areas of Investigation

VIP is also studied for its effects on the gut. Researchers look at how it may relax the muscles in the gut wall, affect how fluid and salts (electrolytes) move, and help maintain the gut's protective lining. Scientists also study its effects on the muscles in the airways. A man-made version called aviptadil has been studied in research related to breathing problems.

All of these are investigational research directions only. None are confirmed or approved uses, and none should be read as proven benefits.

Status

• Regulatory status: Research only, not FDA-approved. VIP is used in lab and research settings and is still investigational (meaning it is being studied, not approved). A related man-made version called aviptadil received a Fast Track label from the FDA for serious COVID-19 cases with breathing failure, but it has not received full FDA approval for that or any other use.
• Sport status: VIP is not listed by name on the WADA Prohibited List (the official list of substances banned in sports). However, VIP is a peptide hormone that the body makes naturally. Athletes who are subject to drug testing should check with their sports organization, because broad rules about peptide hormones could apply.

Reconstitution notes (general)

For freeze-dried (lyophilized) material, the concentration (how strong the solution is) equals the number of milligrams in the vial divided by the number of milliliters of bacteriostatic water you add.

For example, a 10 mg vial mixed with 2 mL of bacteriostatic water gives 5 mg/mL, while the same vial mixed with 1 mL gives 10 mg/mL. Use the peptide calculator to work out the concentration for your vial.

Dilution and handling notes (compound-specific)

Key point: Once mixed with water, VIP breaks down very easily. At room temperature it can fall apart within about 24 to 48 hours. Cold storage and careful handling are essential.

VIP arrives as a freeze-dried (lyophilized) powder. Before using it in the lab, you mix it with liquid. For a 10 mg vial, a common approach is to add between 1 mL and 2 mL of bacteriostatic water. This gives a stock solution in the 5 mg/mL to 10 mg/mL range.

The amount of water you choose depends on the concentration your lab protocol calls for, not on how much the powder can dissolve. The powder usually goes into solution easily. Add the water slowly along the inside wall of the vial, then swirl gently or let it sit. Do not shake. The result should be a clear, colorless liquid.

Handling Challenges and Best Practices

Two things make handling VIP different from many other peptides:

• Diluent choice: Bacteriostatic water is the better choice over plain saline (salt water). Research notes that saline can cause peptide molecules to clump together (aggregate), which lowers quality.
• Chemical fragility: VIP is especially fragile once dissolved. In liquid form, enzymes called peptidases can cut it apart, much like scissors snipping a chain. At room temperature, dissolved VIP can break down within about 24 to 48 hours. That is why solutions must be kept cold and never left sitting out on the bench.

Freezing and thawing the same vial over and over also damages VIP. To avoid this, researchers often split the solution into small single-use portions called aliquots (similar to filling an ice cube tray so you only thaw one cube at a time), and use one portion at a time.

Like most peptides in solution, VIP should be kept away from light. UV and regular visible light can break it down through oxidation (a chemical reaction that degrades the molecule) and light-driven breakdown. Amber-colored or foil-wrapped vials are a common way to block light. Always check for cloudiness or floating particles, which are signs of clumping or breakdown.

Handling and storage

To keep the peptide in good condition, follow these steps:

• Store the mixed solution in the refrigerator at 2 to 8 degrees Celsius and keep it away from light.
• Wipe the rubber stopper with an alcohol swab before each use, and write the mixing date on the vial label.
• Use the solution within about 4 weeks as a general outer limit. Keep in mind that VIP loses quality faster than many other peptides, so the 4-week window is a maximum, not a guarantee.
• Throw away any solution that looks cloudy, has changed color, or has floating particles.
• Keep the freeze-dried powder in the freezer for long-term storage.

Related reading

• 5-Amino-1MQ
• Adamax
• AOD-9604
• How Reconstitution Works
• How Long Does a Reconstituted Vial Last?

Tools and supplies

• peptide calculator
• Bacteriostatic Water 30 ml
• Gansulin Metal Reusable Pen
• 3 ml Glass Cartridges (10-pack)
• Complete Starter Kit

Reminder: research and educational reference only. Preppin Peppers sells hardware and materials, not peptides. Not medical, dosing, or health advice, not evaluated by the FDA, and not intended for human or animal use.

Frequently asked questions

What is VIP in research context?

VIP (Vasoactive Intestinal Peptide) is a synthetic 28-amino acid neuropeptide belonging to a family of signaling proteins, studied in immune and gut research.

How should VIP be stored after reconstitution?

VIP degrades rapidly at room temperature (24-48 hours). Cold storage and careful handling are essential immediately after mixing with bacteriostatic water.

Is VIP FDA approved for any use?

No. VIP is research-only and not FDA-approved. A related synthetic version called aviptadil received Fast Track designation for COVID-19 research but remains unapproved.

What the research community gets wrong about VIP (Vasoactive Intestinal Peptide)

• Assuming it is a sturdy peptide. VIP is one of the more fragile peptides to handle at the bench. Once it is mixed with water, enzymes and plain time can break it apart, and at room temperature a stock can fall apart within about 24 to 48 hours. Keep the solution cold and out of the light.
• Confusing VIP with aviptadil. Aviptadil is a synthetic form of VIP that has been studied in its own research programs. VIP itself is not an approved drug. Do not mix the two up in your lab records or your labels.
• Reaching for plain saline as the diluent. Notes on peptide handling point out that saline can make peptide molecules clump together (aggregate), which lowers the quality of the stock. For benchwork, bacteriostatic water is the safer choice.
• Trusting a clear vial. A clear, colorless liquid is a good sign, but it does not prove the peptide is still intact. Some breakdown happens before you can see any change. Check for cloudiness or floating particles every time, and treat clear as necessary, not as a guarantee.
• Refreezing the same vial. Freezing and thawing one vial over and over damages VIP. Splitting the stock into small single-use portions (aliquots) and thawing one at a time protects the rest.

From our bench: We are collecting real handling notes on VIP in solution. If you have tracked how a reconstituted VIP stock held up in your fridge, tell us what you actually saw: the diluent you used, your storage temperature, whether you split the stock into aliquots, and the day you first noticed cloudiness or particles. We publish reader observations as reported and do not add any numbers we did not measure ourselves.

Sources

1. Bacteriostatic Water for Injection, USP , FDA/DailyMed label (0.9% benzyl alcohol)
2. Duerkop et al., Biotechnol J 2018 , Impact of Cavitation, High Shear Stress and Air/Liquid Interfaces on Protein Aggregation
3. Sigma-Aldrich (Merck) , Handling and Storage Guidelines for Peptides and Proteins
4. PubChem CID 53314964: Vasoactive intestinal peptide (molecular formula and identity)
5. UniProt P01282: VIP peptides (human) - 28-residue mature peptide, processing, and function
6. NCBI Gene 7432: VIP vasoactive intestinal peptide (gene summary, glucagon family)