Storage guide
How a peptide is kept
Where the vial belongs at each stage — the freezer, the fridge, the courier's box — and how long it lasts in each. Storage is the most common reason a peptide loses activity early.
Conditions
Three temperatures
Each stage of the vial's life asks for something different.
−20 °C
Lyophilised powder
The right state for keeping it a long time. As a powder the peptide stays stable at this temperature for months or years.
Lasts: Up to 24 months
2–8 °C
Reconstituted solution
Once dissolved in bacteriostatic water the vial belongs in the fridge, and it is not worth stretching.
Lasts: 30 to 60 days
15–25 °C
In transit, lyophilised
As a powder the peptide tolerates room temperature for weeks or months. A 24-to-72-hour shipment compromises nothing.
Lasts: Weeks or months
Tool
Where is your vial in its window?
Enter the date you reconstituted it and we will tell you where you fall inside the 30-to-60-day window.
Pick the date to see where you stand.
The window is a reference and assumes a solution kept between 2 and 8 °C throughout. It counts calendar days from the date you entered.
Life cycle
From the warehouse to the syringe
Where the vial is at each stage and what it needs there.
01
In our warehouse
The vial is held refrigerated between 2 and 8 °C until dispatch, away from light.
02
Transit and shipping
It travels lyophilised, which is the form that tolerates transport: as a powder it stays stable at room temperature for weeks. That is why a 24-to-72-hour shipment does not compromise it. It leaves in a discreet box.
03
On arrival
If you are not using it within the next few days, move it to the fridge — 2 to 8 °C — as soon as it arrives.
04
Before reconstituting
Take the vial out of the cold and wait 15 to 20 minutes for it to reach room temperature before opening it. That is what stops moisture condensing onto the powder, which would start dissolving it early.
05
While reconstituting
Add the bacteriostatic water at the volume the calculator gives you. Dissolve by rolling gently, label it with the date and the concentration, and refrigerate straight away.
06
After reconstituting
Keep it between 2 and 8 °C and use it within 30 to 60 days. If you need it to last longer, split it into aliquots and freeze them at −20 °C within the first hours. A solution that has been thawed is not frozen again.
Reference table
The conditions, by what state the peptide is in.
| State | Temperature | Maximum time | Light | Notes |
|---|---|---|---|---|
| Lyophilised powder, unopened vial | −20 °C or below | 18 to 24 months | Yes, amber vial | The best option for the long term |
| Lyophilised powder, refrigerated | 2–8 °C | 6 to 12 months | Yes | If you will use it soon |
| Reconstituted solution, refrigerated | 2–8 °C | 30 to 60 days | Yes | Use it within that window |
| Frozen aliquots | −20 °C | Up to 3 months | Yes | Thaw only what you are going to use |
| In transit, lyophilised | Ambient | Weeks | Advisable | Stable as a powder; shipping does not compromise it |
| Reconstituted at room temperature | Above 25 °C | Not advisable | — | It degrades |
Mistakes
What ruins a vial
Storage is the most common reason a peptide loses activity, and it is always the same six lapses.
Avoid
Freeze-thaw cycles
Every cycle degrades the peptide's structure. Once a vial has thawed, use it or keep it in the fridge — do not freeze it again.
Leaving it in direct light
UV and visible light degrade some peptides. Keep it in an amber vial or somewhere dark.
Opening the powder vial again and again
Lyophilised powder takes up moisture from the air every time the vial is opened. If you are using it a little at a time, split it into aliquots.
Not labelling the reconstituted vial
Without the date and the concentration written down there is no way to know whether the solution is still good. Always write them.
Do
Split it into aliquots
Divide the vial into portions before freezing. That way each time you thaw only what you are going to use.
Let it reach room temperature
Before opening a vial that came out of the cold, wait 15 to 20 minutes. That is what prevents condensation on the powder.
Questions about storage
What if the peptide travelled at room temperature?
If it travelled lyophilised — as a powder, which is how it ships — nothing happens. As a powder the peptide tolerates room temperature for weeks and even months, so transit time does not compromise it. To keep it well from then on, move it to the fridge or freezer on arrival. If you notice the powder has caked or changed appearance, write to us.
Can a reconstituted solution be kept beyond 60 days?
It is not worth it. The benzyl alcohol in bacteriostatic water holds back bacterial growth, but it does not stop the peptide's chemical degradation, which proceeds anyway. If you need a vial to last longer, what works is splitting it into aliquots and freezing them at −20 °C right after reconstituting — not stretching the refrigerated vial.
Can I freeze the reconstituted solution?
Yes, but once. Split it into individual aliquots right after reconstituting and freeze them at −20 °C; each aliquot is thawed once and used. What you do not do is thaw, use part of it and refreeze the rest.
How do I know whether a peptide has degraded?
In most cases you cannot tell by eye. What is worth noticing: the solution turning yellowish or cloudy, a precipitate that will not go away, or an unusual smell. When in doubt, do not use it and write to us.
Does bacteriostatic water expire?
It does. Unopened it keeps at room temperature for 2 or 3 years. Once opened, the benzyl alcohol holds sterility for around 28 days; past that it is better to discard that vial and open a new one rather than risk contamination.
Still unsure about keeping it?
Write to us and we will walk you through your vial. If the question is about your treatment, that one is answered by the physician who reviews your consultation.
What is published on this site is general information, not a diagnosis and not an instruction for your case. What applies to you comes out of the intake and the physician's review of it.