How Long Does DSIP Last? Storage Before and After Mixing
Lyophilised DSIP keeps for years sealed, dry and frozen; once mixed with bacteriostatic water it lasts 8 to 12 weeks at 2 to 8 °C under Vistara Labs’ handling guidance, with quality slowly fading from around week 6 to 8. No published stability study covers DSIP in a sterile solution, so that window is the general peptide guidance. The one published breakdown study measured DSIP in blood, where enzymes do the work. Its tryptophan sits at the very front of the chain, so a mixed vial is kept dark and cold, and it is never frozen.
Findings
- DSIP is a 9-amino-acid peptide, Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu, first characterised from rabbits (Schoenenberger and Monnier, PNAS, 1977).
- One chemical supplier rates the solid at −20 °C with stability of at least 4 years; another gives 3 years at −20 °C and 2 years at 4 °C as powder.
- The second supplier gives a stock solution 1 month at −20 °C and 6 months at −80 °C, sealed and away from moisture and light.
- In human and rat blood, DSIP broke down to release tryptophan, at a rate that depended on temperature, time and species (Graf et al., Peptides, 1987).
- It contains no methionine, cysteine or asparagine; its sensitive points are the tryptophan and one aspartate.
How long does DSIP powder last?
Cayman Chemical lists DSIP (as emideltide acetate) for storage at −20 °C with stability of at least 4 years. InvivoChem gives its DSIP acetate powder 3 years at −20 °C and 2 years at 4 °C, kept sealed, away from moisture and light. Moisture is still the main enemy of a freeze-dried cake: it lets the same reactions that happen in solution start in the solid. The DSIP 5 mg vial is kept capped and boxed, in the fridge for near-term work or the freezer for longer holds, and a cold vial is brought to room temperature before opening so that condensation does not form on the powder.
How long does DSIP last after mixing?
At 2 to 8 °C, dark and accessed only through a swabbed stopper, mixed DSIP lasts 8 to 12 weeks, with quality fading from around week 6 to 8. DSIP is named in the general row of how long peptides last after mixing. The DSIP reconstitution page has the calculator for the 5 mg vial.
What the sequence says about stability
Cayman lists DSIP’s solubility in PBS at about 10 mg/mL, and its storage sensitivities are chemical. Oxidation is one of the major ways peptides and proteins degrade in storage, light can drive it, and tryptophan is among the residues most open to it (Li et al., Biotechnol Bioeng, 1995). DSIP’s tryptophan is at position 1. The aspartate at position 5 can slowly form a ring intermediate and isomerise. In model peptides that ring forms faster when the next residue is small, and slower as it gets bulkier (Oliyai and Borchardt, Pharm Res, 1994). In DSIP the residue after aspartate is alanine, not the smallest residue, glycine. The chain has no methionine, cysteine, asparagine or glutamine. The practical result is the same window as most peptides, with extra attention to light, a tight stopper and gentle swirling rather than shaking.
What the frozen-solution figures mean
The supplier’s 1 month at −20 °C and 6 months at −80 °C apply to stock solutions frozen once and kept sealed, a laboratory practice for single-use aliquots. They are not a reason to freeze a working vial that will be thawed and opened again.
How long does DSIP last at room temperature?
There is no published figure for DSIP in a sterile solution at room temperature. The Graf study incubated DSIP in blood, and the breakdown it measured came from blood components, so it does not describe a sealed vial. A mixed vial is taken out of the fridge only for handling, because warmth speeds the chemical reactions above.
Can DSIP be frozen?
The powder can, and the longest supplier figure, at least 4 years, is a −20 °C figure. Single-use aliquots of solution can be frozen once. A working vial should not be frozen and thawed repeatedly, since freeze-thaw cycles aggregate peptides in solution.
How can you tell mixed DSIP has degraded?
- Yellowing or any tint. Mixed DSIP should be clear and colourless.
- Cloudiness that does not clear within 10 to 15 minutes of mixing, or that appears later.
- Particles or sediment.
- Gel or thickening.
Oxidation and isomerisation are invisible, which is why the time window applies even to a vial that still looks perfect.
How long does DSIP nasal spray last?
The DSIP Nasal Spray arrives ready-mixed in sterile saline in a sealed metered pump, so there is nothing to reconstitute. Once opened it is kept at 2 to 8 °C, upright, capped and in the dark, never frozen, and it lasts as long as its label allows. The 8 to 12 week vial window does not carry over, because a spray in saline and a vial in bacteriostatic water are different preparations. Date the bottle on the day it is first opened, and discard it if the solution turns cloudy, shows particles or changes colour. The full routine is in how to store a peptide nasal spray.
DSIP storage at a glance
| State | Where | How long |
|---|---|---|
| Powder, sealed | −20 °C, dry, dark | 3 years to at least 4 years (supplier data sheets) |
| Powder, sealed | 4 °C, dry, dark | 2 years (supplier data sheet) |
| Mixed with bacteriostatic water | 2 to 8 °C, dark | 8 to 12 weeks, fading from week 6 to 8 (store guidance) |
| Solution aliquots, frozen once | −20 °C / −80 °C | 1 month / 6 months (supplier data sheet) |
| Mixed, room temperature | Handling only | No published figure |
Certificates of analysis are on the lab reports page, and every order ships from within Canada by Canada Post Xpresspost.
Vistara Labs supplies DSIP as a laboratory research material. The windows on this page describe how long the peptide stays in good condition.
Frequently asked questions
How long does DSIP last in the fridge after mixing?
Under Vistara Labs’ handling guidance, 8 to 12 weeks at 2 to 8 °C in the dark, with quality fading from around week 6 to 8.
How long does DSIP last at room temperature?
No published figure exists for DSIP in a sterile solution at room temperature. A mixed vial is kept in the fridge and taken out only for handling.
Can you freeze DSIP?
Yes as powder: one supplier rates it at −20 °C for at least 4 years. Solution can be frozen once as single-use aliquots, but a working vial should not go through repeated freeze-thaw cycles.
Does DSIP go bad?
Yes. Its tryptophan oxidises and its aspartate can isomerise slowly in solution, faster with warmth and light. Cloudiness, particles, a tint or gel mean it has degraded.
Does DSIP nasal spray keep as long as a mixed vial?
Not by assumption. The spray is a different preparation in saline, so an opened bottle lasts as long as its label allows, kept at 2 to 8 °C, upright, capped and dark.
Handling windows: Vistara Labs, October 2026. Sources: Schoenenberger GA, Monnier M. Characterization of a delta-electroencephalogram (-sleep)-inducing peptide. Proc Natl Acad Sci USA. 1977. PMID 265572. Graf MV et al. Degradation and aggregation of delta sleep-inducing peptide (DSIP) and two analogs in plasma and serum. Peptides. 1987. PMID 3628078. Oliyai C, Borchardt RT. Chemical pathways of peptide degradation. VI. Effect of the primary sequence on the pathways of degradation of aspartyl residues in model hexapeptides. Pharm Res. 1994. PMID 8058648. Li S, Schöneich C, Borchardt RT. Chemical instability of protein pharmaceuticals: mechanisms of oxidation and strategies for stabilization. Biotechnol Bioeng. 1995. PMID 18623513. Cayman Chemical. Emideltide (acetate), item 34426, product information: storage and stability. PDF. InvivoChem. δ-Sleep Inducing Peptide acetate, V64516, product page: sequence and storage. Data sheet.
More on this: How Long Do Peptides Last After Mixing?
All products supplied by Vistara Labs are intended for laboratory research use only. They are not drugs, are not approved for human or veterinary use, and are not intended to diagnose, treat, cure or prevent any condition. Nothing on this page constitutes medical advice or guidance for use in humans.
