DSIP (Delta Sleep-Inducing Peptide): Reference Overview and Reconstitution Notes

DSIP is a small protein fragment that occurs naturally in the body. It is made of nine building blocks called amino acids. Researchers group it with compounds studied for their effects on sleep and hormones. It is for research use only and is not approved by the FDA for any use in people.

DSIP (Delta Sleep-Inducing Peptide)

What it is

DSIP, short for Delta Sleep-Inducing Peptide, is a small, naturally occurring neuropeptide (a chemical messenger used by the nervous system). It is built from nine amino acids (the building blocks of proteins), in this exact order: Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu. It weighs about 850 daltons (a dalton is a tiny unit scientists use to measure how heavy a molecule is). Its structure is amphipathic, meaning one part mixes easily with water while another part repels it, similar to how soap works.

Scientists first isolated it in the 1970s from blood drawn near the brains of sleeping rabbits. Its name comes from early reports that it boosted delta-wave brain activity. Delta waves are the slow brain waves recorded during deep sleep, measured with a device called an EEG. The material sold for laboratory use is made through chemical synthesis, not taken from animal tissue.

Research context and categorization

DSIP is grouped with research compounds studied for effects on sleep and hormones (chemical messengers that control many body functions). In published studies, it is most often discussed in relation to sleep architecture (the pattern and timing of sleep stages) and slow, deep sleep.

Researchers have also looked at it in connection with how the body handles stress, the HPA axis (a system linking the brain and adrenal glands that manages the stress response), pain and the body's reaction to opioid drugs, brain protection, and the release of certain hormones. Because of these connections, it sometimes comes up in recovery and stress research, not just sleep studies.

Key point: Most research on DSIP is old, done on small groups, and still debated. There is very little evidence from human studies. It remains an experimental substance with no approved or confirmed benefits in people.

Status

• Regulatory status: Research only. DSIP is not approved by the FDA for insomnia, anxiety, depression, or any other medical condition. It is an experimental, unapproved substance. A regulatory review of DSIP (also called emideltide) for a special compounding list has been discussed for a 2026 advisory committee meeting, but that review process is not the same as approval.
• Sport status: DSIP is not listed by name on the WADA Prohibited List (the official list of substances banned in sport). However, because it is not an approved drug, it can fall under class S0 (Non-Approved Substances), which bans any substance that no government health agency has approved for human use. Athletes subject to drug testing should treat DSIP as potentially prohibited and check directly with their sport's anti-doping authority before any laboratory use.

Reconstitution notes (general)

Lyophilized (freeze-dried) peptides are typically mixed with bacteriostatic water (water with a small amount of preservative to slow bacterial growth) before use in the lab. Calculating the working concentration is simple math: divide the milligrams of peptide in the vial by the milliliters of water added.

For example, 5 mg of powder mixed into 2.5 mL of water gives a concentration of 2 mg/mL. A reconstitution calculator is available at peptide calculator to check the math for any vial and fill volume.

Dilution and handling notes (compound-specific)

Reconstitution Ratios

DSIP is supplied as a freeze-dried powder, usually in 5 mg or 10 mg vials, and is mixed with water for laboratory use. Common working concentrations fall in the range of about 1 to 5 mg/mL.

Because of this, a 5 mg vial is often paired with about 1 to 2 mL of bacteriostatic water, and a 10 mg vial with about 2 to 3 mL. The amount of water chosen depends on what concentration the researcher needs for accurate small-volume measurements. There is no single fixed rule.

More water produces a more dilute solution that is easier to measure in fine increments. Less water produces a more concentrated solution in a smaller volume. DSIP dissolves easily and normally reaches its final appearance within a few minutes of gentle mixing, without turning into a gel.

Solution Appearance and Concentration

Because DSIP is amphipathic (partly water-loving and partly water-repelling, like a soap molecule), a faint haziness or cloudiness can appear at higher concentrations, roughly above 1 mg/mL. This is a normal physical property and does not by itself mean something went wrong with the mix.

Very dilute solutions, below about 0.5 mg/mL, tend to look crystal-clear. Pushing the concentration much higher, above about 10 mg/mL, raises the risk of visible solid crystals forming in the liquid.

The practical fix is to keep the concentration in a moderate range rather than over-concentrating a single vial. Cloudiness that appears and will not go away, or that persists well past the first few minutes, points to clumping of molecules (aggregation) rather than normal haziness, and should be treated as a problem.

Handling Quirks and Light Sensitivity

Two handling details are worth noting. First, DSIP contains a tryptophan building block and is light-sensitive. It must be kept away from direct light, using amber vials or shielded storage, to limit oxidation (chemical breakdown caused by exposure to light and air).

Second, add the bacteriostatic water slowly down the inner glass wall of the vial rather than squirting it straight onto the powder. Swirl or roll the vial gently instead of shaking or vortexing it, since vigorous mixing creates foam, and the air-liquid interface at the bubbles can break down peptide molecules.

Let both vials warm to room temperature before mixing, and wipe the rubber stoppers with an alcohol swab. This helps the powder dissolve cleanly. After mixing, inspect the solution for clarity before laboratory use.

Handling and storage

To preserve peptide stability, researchers typically follow these storage and handling steps:

• Store the mixed vial in the refrigerator at 2 to 8 degrees Celsius and keep it protected from light.
• Wipe the rubber stopper with an alcohol swab before each needle puncture.
• Write the mix date on the vial label so its age can be tracked.
• Use the refrigerated solution within about four weeks (around 28 days) when bacteriostatic water is used.
• Discard any vial that turns cloudy and stays that way, changes color, or shows floating particles or solid bits.

Related reading

• Epitalon
• Follistatin
• FOXO4-DRI
• 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 the chemical structure of DSIP?

DSIP is a nonapeptide with the sequence Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu, molecular weight ~850 daltons, and an amphipathic structure. Lab-grade material is produced by chemical synthesis.

Is DSIP FDA-approved or banned in sport?

DSIP is not FDA-approved for any condition. It is not named on the WADA Prohibited List but may fall under class S0 (Non-Approved Substances). Athletes subject to testing should consult their anti-doping authority.

How do researchers reconstitute lyophilized DSIP for laboratory use?

Add a measured volume of bacteriostatic water to the lyophilized vial, then calculate working concentration by dividing mg of peptide by mL of water added (e.g., 5 mg ÷ 2.5 mL = 2 mg/mL).

What the research community gets wrong about DSIP handling

A few handling ideas get passed around that do not match how DSIP actually behaves in the vial. Here are the ones worth clearing up.

• Faint haze does not always mean a bad vial. Because DSIP is amphipathic (partly water-loving, partly water-repelling), a light cloudiness can show up at higher concentrations, roughly above 1 mg/mL. That is a normal physical property. Haze that appears late or will not clear is a different problem and points to clumping (aggregation).
• Shaking does not speed things up. DSIP usually dissolves within a few minutes of gentle swirling. Shaking or vortexing whips in foam, and the air-to-liquid surface at those bubbles can break the peptide apart. Roll or swirl the vial instead.
• It does not need a fancy solvent. At moderate concentrations DSIP goes into bacteriostatic water on its own. Reaching for acids or organic solvents adds variables you do not need for a simple bench prep.
• Light matters more than people expect. DSIP carries a tryptophan building block, which makes it sensitive to light. Leaving the vial out under bench lighting is not harmless. Use amber vials or keep it shielded and cold.
• A mixed vial is not good forever. Once reconstituted with bacteriostatic water, plan on using it within about four weeks refrigerated, and skip repeated freeze-thaw cycles, which stress the peptide each time.

From our bench: Next time you reconstitute a DSIP vial, note the concentration you mixed to and watch the first ten minutes. Record how long the powder took to fully dissolve with gentle swirling, whether the solution stayed clear or turned faintly hazy, and if any haze cleared on its own. Send us your reading and we will add real observations to this page instead of general ranges.

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. Graf MV, Kastin AJ. Delta-sleep-inducing peptide (DSIP): a review. Neurosci Biobehav Rev. 1984 (PMID 6145137)
5. Schoenenberger GA, et al. The delta EEG (sleep)-inducing peptide (DSIP): amino-acid analysis, sequence, synthesis and activity. Pflugers Arch. 1978 (PMID 568769)
6. Delta Sleep-Inducing Peptide, C35H48N10O15, CID 68816 , PubChem (NIH/NLM)