Shipping and Cold Weather

Your order may sit in a mailbox at −25 °C for a few hours before you get to it. Here is what that actually means for each format, and what to do when the parcel comes in from the cold.

This page describes handling practice for laboratory research materials. It contains no dosing information and no guidance on use in humans or animals. Everything Horizon Peptides supplies is for research use only.

Why peptides ship without a cold chain at all

Research peptides are supplied as lyophilized powder — freeze-dried, with the water removed. Water is what most degradation pathways need, so taking it out is what makes the material tolerant of the days it spends in transit. That is why a cold pack is not standard for this category, in January or in July.

It also means the usual winter worry is the wrong way round. A sealed vial of dry powder is a far more robust thing than people expect, and cold is the direction it is already stored in: long-term guidance for lyophilized peptide is −20 °C to −80 °C. A mailbox in Winnipeg in February is not an unusual environment for it.

The one thing that genuinely matters: condensation

The risk on a cold parcel is not the cold. It is what happens when you bring it inside.

A vial that has been at −25 °C and is opened straight away in a warm kitchen pulls moisture out of the room air and onto the cold glass and powder. Moisture is the thing lyophilization was carried out to remove.

So: let the parcel reach room temperature before you open any vial. Leave it sealed, out of the box, for a couple of hours. This is the same rule the storage guide gives for taking a vial out of a freezer — it just matters more between November and March, because the temperature gap is bigger.

The formats behave differently, and this is where to pay attention

If you are ordering a spray, a pen or a cream in deep winter and the parcel is likely to sit outside, that is the case worth planning around — not the vials.

Practical things that help

• Order earlier in the week. Dispatch is Monday to Friday, before 2:00 PM ET for same-day. An order placed on Friday afternoon sits over the weekend.
• Use an address where it comes indoors. A parcel that goes to a workplace or a locker rather than an unheated porch spends far less time at ambient.
• Watch the tracking, not the clock. Canada Post tracking can read “label created” for a day or so until the parcel is physically scanned in. That is normal and does not mean it is sitting somewhere cold.
• Let it warm before opening. The one rule on this page that matters more than the others.

If something looks wrong on arrival

A cake of powder that has shifted or slumped in transit is cosmetic — it is loose material in a sealed vial and it moves. A vial where the seal is compromised, the stopper has lifted, or a liquid format has obviously frozen and separated is a different matter.

In that case, get in touch with your order number and a photograph before using it. The return policy sets out what is covered and the window for it; read that rather than assume either way.

What this page deliberately does not say

You will find a great deal written online about exactly how many freeze-thaw cycles a given sequence tolerates, usually with confident numbers attached. We are not going to add to it. What we can tell you is what format you are receiving, how it is stored before it ships, what the published handling guidance says, and that the certificates for each batch are published by batch number. Anything beyond that would be a claim rather than a fact.