One of the most common questions I see is:

"Do I keep it in the cupboard, fridge or freezer?"

The answer depends on what stage your research compound is in.

🧪 Lyophilised (Freeze-Dried) Peptides

This is the most stable form.

Short-term (days to weeks)

• Room temperature is generally fine during shipping or if you'll be using it soon.
• Keep it somewhere cool, dry and away from direct sunlight.

Long-term (months+)

• Store at -20°C (standard freezer) if you won't be using it for a while.
• Refrigeration (2-8°C) is also commonly used for medium-term storage, but freezing is preferred for maximum stability.

Things that damage lyophilised peptides

• Moisture (the biggest enemy)
• Direct sunlight / UV
• High heat
• Opening a cold vial before it has warmed to room temperature (condensation introduces moisture)

💧 Reconstituted Peptides (Mixed with BAC Water)

Once water has been added, stability decreases significantly.

General recommendations:

• Store in the refrigerator (2-8°C)
• Keep protected from light
• Avoid repeated warming and cooling
• Avoid repeated freeze-thaw cycles, which can reduce peptide stability.

💉 Bacteriostatic Water

Unopened

• Store at room temperature in a cool, dry place.
• Avoid excessive heat and direct sunlight.

After opening

• Many laboratories choose to refrigerate after first use to minimise bacterial growth and temperature fluctuations, although manufacturers often allow controlled room-temperature storage. Follow the product label where available.

☀️ Does Shipping in Summer Ruin Peptides?

Usually no.

Lyophilised peptides are specifically freeze-dried because they're far more stable during transport than peptides already in solution. A few days in transit, even in warm weather, is generally not considered enough to meaningfully degrade an unopened lyophilised vial.

⚠️ General Tips

✔ Keep products dry.

✔ Keep them out of direct sunlight.

✔ Let frozen vials return to room temperature before opening to prevent condensation.

✔ Try to avoid unnecessary temperature cycling.

✔ Once a peptide is in solution, treat it as significantly more delicate than the original powder.

This is general storage information only. Stability ultimately depends on the specific peptide sequence, formulation and manufacturer recommendations, so if guidance differs for a particular compound, follow the supplier's documentation.