Whether a peptide remains stable for months or loses quality within days depends primarily on one thing: storage. This guide summarizes common practices in a laboratory context.

Two States, Two Rules

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

Lyophilizate – The Unopened Powder

In the freeze-dried state, peptides are remarkably stable because there is little water available for degradation reactions. Coolness, dryness, and darkness are crucial.

• Short-term (weeks): Refrigeration at 2–8 °C is usually sufficient.
• Long-term (months and longer): Freezing at -20 °C or colder is common.
• Keep dry: Moisture is the main enemy. Do not open the sealed vial in a humid environment; avoid condensation by allowing a cold vial to reach room temperature before opening.
• Store protected from light in the original container.

Reconstituted Solution – After Dissolving

Once the powder is dissolved in water, stability shortens significantly. From this point on, consistent refrigeration is essential.

• Dissolved material is stored at 2–8 °C in the refrigerator, not at room temperature.
• Repeated freezing and thawing should be avoided – each cycle stresses the molecular structure. If freezing, do so in a single portion if possible.
• Protect the vial from light and store it upright.
• The shelf life of the dissolved state is limited depending on the compound – from a few days to several weeks.

The Role of Water

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

• Sterile water contains no preservative. Solutions prepared with it have a very short shelf life.
• Bacteriostatic water (BAC) contains 0.9% benzyl alcohol, which inhibits germ growth. It significantly extends the shelf life of the solution and is the usual method in a laboratory context. BAC water is included with every SENEX order.

Light-Sensitive Compounds

Some compounds are also light-sensitive. GHK-Cu, for example, is a copper peptide whose blue-green color also serves as a freshness indicator: if it fades, the copper has detached. Such compounds are consistently stored in the original vial and in the dark.

Rules of Thumb at a Glance

State	Temperature	Light	Shelf Life (Guideline)
Lyophilizate, short-term	2–8 °C	dark	Weeks
Lyophilizate, long-term	-20 °C or colder	dark	Months+
Reconstituted (BAC)	2–8 °C	dark	Days to weeks
Reconstituted (sterile)	2–8 °C	dark	very short

The values are general guidelines and vary depending on the compound. The batch-specific data sheet is always authoritative.

All information is for general, scientific, and research purposes only. The products offered by SENEX are not intended for human or animal consumption. This page does not constitute instructions for use, dosage recommendations, or medical advice. For health questions, please consult medical or pharmaceutical professionals.