Peptides degrade. Heat, light, oxygen, repeated freeze-thaw cycles — all of them eat into the active compound from the day the vial leaves the supplier. Here’s how to maximise shelf life at each stage: from the moment your vial arrives to the moment it’s empty.
Lyophilised (dry) storage
Before reconstitution, peptides are freeze-dried into a fluffy white solid. In this state they’re remarkably stable — sealed under vacuum, with no water for hydrolysis to attack, the peptide bonds can sit for years.
| Storage condition | Typical shelf life | Notes |
|---|---|---|
| Room temperature (15–25°C) | Up to 30 days | For short-term transit only — not for storage beyond delivery week |
| Refrigerated (2–8°C) | 12–24 months | Standard storage. Most supplier recommendations. |
| Frozen (−20°C) | 2–3 years | Maximum shelf life for unmixed vials. Use for long-term inventory. |
| Deep-frozen (−80°C) | 5+ years | Lab-grade only. Overkill for individual research use. |
For most researchers, refrigeration is enough. If you’re buying more than 3 months’ supply at once, consider freezing the spare vials and pulling them to the fridge a few days before use.
Reconstituted storage
Once you add BAC water, the clock starts. Water enables hydrolysis — the chemical reaction that breaks peptide bonds. Refrigeration slows it dramatically but doesn’t stop it.
| Reconstitution diluent | Refrigerated shelf life | Notes |
|---|---|---|
| Bacteriostatic water (0.9% benzyl alcohol) | 28 days | Standard for multi-dose vials. The preservative prevents bacterial growth. |
| Sterile water (no preservative) | 24–48 hours | Single-use only. Bacterial growth after 48h makes it unsafe regardless of refrigeration. |
| Saline (0.9% NaCl) | 5–7 days | Some compounds prefer saline (e.g. some GLPs); same single-use logic applies if no preservative. |
The 28-day window for BAC water is the standard you’ll see across most supplier documentation and pharmacopoeia. It’s not arbitrary — it’s the window during which the preservative reliably suppresses bacterial growth AND peptide degradation stays below clinically significant levels.
Compound-specific variations
A few peptides degrade faster than the generic 28-day rule:
- HGH (somatropin): ~21 days reconstituted. More thermolabile than smaller peptides.
- Tesamorelin: 14–21 days reconstituted. Protein-class compound, similar profile to HGH.
- Most short peptides (BPC-157, TB-500, GHK-Cu, etc.): 28+ days. The short peptide chain is more robust against hydrolysis.
The compound page for each peptide lists its specific shelf-life — see the peptide library.
Never freeze a reconstituted vial
If you need long-term storage, leave the vial unmixed and freeze the dry powder. Don’t reconstitute and then freeze. The single biggest peptide-waste mistake is freezing a mixed vial because “the fridge is full.”
Travelling with peptides
Two scenarios:
Same-day travel (within 8 hours)
An insulated bag with a small ice pack keeps a reconstituted vial in the safe range. Don’t let it directly contact frozen surfaces. Most consumer cooler bags are fine — the kind you’d use for groceries on a hot day.
Multi-day travel
Don’t bring a reconstituted vial. Take the dry vial and a separate BAC water vial; reconstitute at the destination. The dry vial is room-temperature stable for up to 30 days during transit — well within any normal travel window.
How to tell when a vial has gone bad
Visual inspection catches most issues. Look for:
- Cloudiness in a previously clear solution. Cloudy = either bacterial growth or peptide aggregation. Either way, discard.
- Particulates floating in the liquid. Specks, fibres, anything solid. Discard.
- Discolouration. Most peptide solutions are colourless; some are very faintly yellow. A pronounced colour change (especially toward yellow, brown, or pink) means degradation. Discard.
- An off smell from the stopper area. Solutions that should be near-odourless shouldn’t develop a smell. Bacterial contamination has a faint sour or off-smell.
- Loss of effect over a cycle. Subjective and slow to register, but if the same dose stops producing measurable changes mid-cycle, the vial may have degraded — or your physiology may have adapted (cycling exists for this reason).