A peptide handles shipping without a fridge because it travels to you as lyophilised powder, freeze-dried, and without water the main route of its breakdown is closed. The changes described in storage studies are measured in weeks, not in the few days a parcel spends with a courier. Below is what protects a peptide in transit, what has been measured in storage studies, and what to do with the vial as soon as it arrives.
Water breaks peptides down, and lyophilised powder has none
The peptide bond breaks down mainly in a reaction with water. Lyophilisation removes water by sublimation, turning ice straight into vapour from the frozen solution. What remains at the bottom of the vial is a cake or a thin layer of powder, sometimes so fine it is barely visible. Without water the main route of breakdown is closed, which is why powder tolerates room temperature much better than a ready solution.
The same shows in shelf lives. A solution after dissolving keeps for weeks in the fridge, while powder in a vial is counted in months. The difference does not come from the quality of the peptide, only from the presence of water in the vial.
What a study on lyophilised secretin measured
In 2015 the International Journal of Pharmaceutics published a study on the stability of lyophilised secretin, a peptide hormone used in diagnostics. Samples were kept for eight weeks under four conditions: at minus 20 degrees, at 4 degrees, at 25 degrees, and at 25 degrees with 60 per cent relative humidity. Secretin content was measured by HPLC, and particles after dissolving by dynamic light scattering.
After eight weeks the concentration had fallen by 20 to 27 per cent, depending on conditions. Heat combined with humidity did worst: at 25 degrees and 60 per cent humidity the particles grew from about 390 nanometres to over 2 micrometres after the first week, and dissolving time lengthened from about 20 seconds to about 67 seconds after eight weeks. The scale of these changes is measured in weeks and depends mainly on humidity, not on a few days in a courier's box.
Why the quality of drying at the manufacturer matters
A second paper in the same journal, from 2000, dealt with lyophilised atrial natriuretic peptide. The authors showed that multimers, clumped peptide molecules, form in the dry powder, and that their amount grows with storage time. The size of this effect depended on the lyophilisation cycle and on the amount of mannitol used as a bulking agent.
The conclusion for a buyer is simple. The stability of a vial depends not only on how it was transported but also on how it was dried and what it was filled with. That is why it is worth having a certificate of analysis for every batch, because it describes the contents of that particular lot.
How long the parcel is on the way
Orders are dispatched within 24 hours of the payment clearing or of cash on delivery being confirmed. The parcel goes by courier or to a parcel locker, and the vials are packed so that they do not knock against each other in transit. The contents are not described on the outside of the parcel.
Shipping from Poland to your country costs 30 EUR when you pay in advance or 80 EUR cash on delivery, the same for every country. The details are on the shipping and payments page. Within Poland a parcel usually arrives in one or two working days, far shorter than the weeks in the studies above.
Four situations side by side
| Form | Condition | What happens | What to do |
|---|---|---|---|
| powder in a vial | a few days in transit, room temperature | no measurable change on this timescale | collect it and put it away when you get home |
| powder in a vial | weeks in heat and humidity | lower content and slower dissolving | keep it in the fridge or freezer |
| ready solution | room temperature | faster breakdown than as powder | keep it in the fridge, in the dark |
| ready solution | freezing and thawing | risk of loss with every cycle | do not freeze after reconstitution |
What to do with the vial after it arrives
Unpack the parcel and check that the stopper is intact and that the powder or cake is at the bottom. Put the powder vial in the fridge, or in the freezer if you plan longer storage. Dissolve the peptide only when you intend to use it, because from that moment the shorter shelf life applies. The steps are set out in the guide to reconstitution with bacteriostatic water, and shelf lives in the guide to storing peptides.
If you are still choosing a molecule, the price list shows prices and availability for every item, and the individual compounds are described in the shop. Every one of these vials travels to you in the same robust form.
Frequently asked questions
Does a peptide need to be shipped on ice?
No. Lyophilised powder contains no water, so a few days of transport at room temperature do not change it measurably.
What do studies say about storage in the heat?
In the study on lyophilised secretin the content fell by 20 to 27 per cent only after eight weeks, fastest at 25 degrees and 60 per cent humidity.
How can I tell the vial arrived in good condition?
The stopper is intact, and there is powder or a compact cake at the bottom. The layer can be very thin, and that is normal.
Where should I keep a peptide after it arrives?
Powder in the fridge, and in the freezer for longer storage. A ready solution only in the fridge, without freezing.
How long does shipping take and what does it cost?
We dispatch within 24 hours. Shipping to your country costs 30 EUR paid in advance or 80 EUR cash on delivery.
Sources
- Srinivasan C, Siddiqui A, Korang-Yeboah M, Khan MA. Stability characterization and appearance of particulates in a lyophilized formulation of a model peptide hormone-human secretin. International Journal of Pharmaceutics, 2015, 481(1-2): 104-113. https://doi.org/10.1016/j.ijpharm.2015.01.044
- Wu SL, Leung D, Tretyakov L et al. The formation and mechanism of multimerization in a freeze-dried peptide. International Journal of Pharmaceutics, 2000, 200(1): 1-16. https://doi.org/10.1016/s0378-5173(99)00469-x