Storage & Stability

Whether a peptide remains stable for months or loses quality within days depends above all on one thing: storage. This guide summarises standard practice in the laboratory setting.

Two states, two rules

Peptides are supplied as a lyophilisate (freeze-dried powder) and only dissolved in water (reconstituted) when needed. These two states behave completely differently – and are stored accordingly.

Lyophilisate – the unopened powder

In the freeze-dried state, peptides are remarkably stable because there is hardly any water available for degradation reactions. What matters is keeping them cool, dry and dark.

• Short term (weeks): a refrigerator at 2–8 °C is generally sufficient.
• Long term (months and longer): freezing at −20 °C or colder is standard.
• Keep dry: moisture is the main enemy. Do not open the sealed vial in a humid environment; avoid condensation by letting a cold vial reach room temperature before opening.
• Protect from light by storing in the original container.

Reconstituted solution – after dissolving

Once the powder is dissolved in water, stability drops considerably. From this point on, consistent refrigeration applies.

• Dissolved material is kept in the refrigerator at 2–8 °C, not at room temperature.
• Repeated freezing and thawing is avoided – every cycle stresses the molecular structure. If you freeze, do so in a single portion where possible.
• Protect the vial from light and store it upright.
• Shelf life in solution is limited and depends on the compound – from a few days to several weeks.

The role of water

Two types of water can be used for dissolving, and they differ significantly:

• Sterile water contains no preservative. Solutions prepared with it keep for only a very short time.
• Bacteriostatic water (BAC) contains 0.9 % benzyl alcohol, which inhibits microbial growth. It extends the shelf life of the solution considerably and is the usual choice in the laboratory setting. Bacteriostatic water is available from laboratory suppliers – and Peptélia includes it with every order.

Light-sensitive compounds

Some compounds are also sensitive to light. GHK-Cu, for example, is a copper peptide whose blue-green colour doubles as a freshness indicator: if it fades, the copper has dissociated. Such compounds are always stored in the original vial and kept dark.

Rules of thumb at a glance

These values are general guidance and vary by compound. The batch-specific data sheet always takes precedence.

All information is provided solely for general, scientific and research-related information purposes. The products offered by Peptélia are not intended for human or animal consumption. This page does not constitute instructions for use, a dosing recommendation or medical advice. For health-related questions, please consult a physician or pharmacist.