Peptide storage and stability reference tables
Quick-reference tables for laboratory staff: how storage conditions differ between lyophilized powder and solution, which residues are most prone to chemical change, and what common solvents are used for. General chemistry only. For background, read the peptide storage and stability guide.
1. Storage by physical state
| State | Typical laboratory condition | Main concerns |
|---|---|---|
| Lyophilized powder, sealed | -20°C, dry, dark; -80°C for long-term archives | Moisture uptake when opened cold; light for Trp/Tyr-containing sequences |
| Lyophilized powder, short handling | Room temperature for hours to days in a sealed vial (shipping, weighing) | Humidity; keep desiccated |
| Stock solution | 2–8°C short term; frozen single-use aliquots for longer periods | Hydrolysis, deamidation, oxidation, microbial growth, adsorption to plastic or glass |
| Working dilution | Prepared fresh, kept cold and protected from light | Low concentrations lose a larger fraction to surface adsorption |
2. Residues and motifs prone to chemical change
| Residue / motif | Pathway | Common precautions |
|---|---|---|
| Met (M) | Oxidation to methionine sulfoxide (+16 Da) | Limit air and headspace; degassed solvents; avoid peroxide-containing reagents |
| Cys (C) | Oxidation; disulfide formation or scrambling | Slightly acidic pH, low oxygen; free thiols oxidize faster at basic pH |
| Trp (W), Tyr (Y) | Photo-oxidation | Amber vials or foil; avoid light |
| Asn (N), Gln (Q) | Deamidation (+0.98 Da), fastest at Asn-Gly | Avoid neutral-to-basic pH and warm storage in solution |
| Asp-Gly, Asp-Ser | Aspartimide formation and isoAsp isomerization | Avoid prolonged storage in solution |
| N-terminal Gln or Glu | Cyclization to pyroglutamate (−17 / −18 Da) | Keep cold; minimize time in solution |
| Hydrophobic stretches | Aggregation, poor solubility | See solubility and aggregation guide |
Mass shifts above help when reading mass spectrometry results. Use the pI and net charge calculator to check where a sequence is least soluble.
3. Common solvents and diluents
| Solvent | Typical lab use | Notes |
|---|---|---|
| Sterile water | Charged, hydrophilic sequences | No preservative; single-use |
| Bacteriostatic water (0.9% benzyl alcohol) | Multi-draw stock solutions | Preservative can interact with some assays; see bacteriostatic vs sterile water |
| Dilute acetic acid (about 0.1–1%) | Basic peptides (net positive charge) | Low pH also slows deamidation |
| Dilute ammonium bicarbonate or ammonia | Acidic peptides (net negative charge) | Basic pH speeds Cys oxidation and deamidation |
| DMSO, then dilute | Very hydrophobic sequences | Can oxidize Met and Cys; check assay tolerance |
| Acetonitrile / water | HPLC and LC-MS sample preparation | Analytical use; see reading an HPLC chromatogram |
4. Stated storage for catalogue compounds
Storage as stated on each product page, with residues from the table above that appear in the listed sequence (standard residues only).
| Compound | Stated storage | Sensitive residues in sequence |
|---|---|---|
| 5-Amino-1MQ 50mg | -20°C lyophilized | Sequence not listed as standard residues |
| Adamax | -20°C lyophilized; 2–8°C reconstituted | Sequence not listed as standard residues |
| B12 25mg 10ml | 2–8°C, protect from light | Sequence not listed as standard residues |
| BPC-157 | -20°C lyophilized; 2–8°C reconstituted | None of the listed residues |
| BPC-157 / TB-500 Blend | -20°C lyophilized; 2–8°C reconstituted | Sequence not listed as standard residues |
| Cagrilintide 10mg | -20°C lyophilized | Sequence not listed as standard residues |
| CJC-1295 / Ipamorelin Blend (no DAC) | -20°C lyophilized | Sequence not listed as standard residues |
| CJC-1295 w/ DAC | -20°C lyophilized; 2–8°C reconstituted | Sequence not listed as standard residues |
| DSIP 5mg | -20°C lyophilized | Trp (oxidation, light) |
| Glow Blend | -20°C lyophilized; 2–8°C reconstituted | Sequence not listed as standard residues |
| HCG | -20°C lyophilized; 2–8°C reconstituted | Sequence not listed as standard residues |
| IGF-1 LR3 | -20°C lyophilized; 2–8°C reconstituted | Sequence not listed as standard residues |
| Kisspeptin-10 10mg | -20°C lyophilized | Trp (oxidation, light); Asn/Gln (deamidation) |
| Klow Blend | -20°C lyophilized; 2–8°C reconstituted | Sequence not listed as standard residues |
| MOTS-C | -20°C lyophilized; 2–8°C reconstituted | Met (oxidation); Trp (oxidation, light); Asn/Gln (deamidation) |
| MT-1 10mg | -20°C lyophilized; 4°C in solution up to 2 weeks | Sequence not listed as standard residues |
| MT-2 10mg | -20°C lyophilized | Sequence not listed as standard residues |
| NAD+ | -20°C, protect from light and moisture | Sequence not listed as standard residues |
| Oxytocin | -20°C lyophilized; 2–8°C reconstituted | Sequence not listed as standard residues |
| PT-141 (Bremelanotide) | -20°C lyophilized; 2–8°C reconstituted | Sequence not listed as standard residues |
| Retatrutide | -20°C lyophilized; 2–8°C reconstituted | Sequence not listed as standard residues |
| Selank 10mg | -20°C lyophilized; 4°C in solution up to 2 weeks | None of the listed residues |
| Semax | -20°C lyophilized; 2–8°C reconstituted | Met (oxidation) |
| SS-31 50mg | -20°C lyophilized; 4°C in solution up to 2 weeks | Sequence not listed as standard residues |
| Tesamorelin | -20°C lyophilized; 2–8°C reconstituted | Sequence not listed as standard residues |
| Tirzepatide | -20°C lyophilized; 2–8°C reconstituted | Sequence not listed as standard residues |
Storage FAQ
Why are lyophilized peptides stored frozen?
Removing water slows hydrolysis, deamidation and microbial growth, and low temperature slows the remaining chemical reactions. Keeping the vial sealed, dry and dark at about -20°C is the usual laboratory default; -80°C is used for long-term archives.
Why does a peptide in solution degrade faster than the powder?
In solution, water takes part in hydrolysis and deamidation, dissolved oxygen drives oxidation of Met, Cys and Trp, and molecules can aggregate or adsorb to surfaces. Solutions are therefore usually kept cold, protected from light and divided into single-use aliquots.
Why avoid repeated freeze-thaw cycles?
Each cycle concentrates solutes in the unfrozen fraction, shifts pH and exposes the peptide to ice-water interfaces, which can promote aggregation. Single-use aliquots avoid repeated cycles.
Should I let a frozen vial warm up before opening it?
Yes. Opening a cold vial lets room-air moisture condense on the powder. Letting the sealed vial reach room temperature (often in a desiccator) first limits moisture uptake.
Does this table give shelf-life dates?
No. It summarizes general chemistry. Stability depends on the specific sequence, salt form, residual moisture, container and handling. Follow the storage condition stated on each product page and your own laboratory records.
Related guides and tools
Research use only. For laboratory research use only. Not for human or veterinary use. These tables summarize general chemistry and give no use or dosing guidance.
