The standard advice is a climate-controlled chain from factory to fridge, and panic if a package sat on a porch for an afternoon. The founder of Janoshik has a better data point than anyone on the forums: a bag of growth hormone he forgot in his garage for ten years, then tested. The answer splits cleanly in two, and the split is whether water has gone into the vial.
Research use only. Compound Review scores vendors on documentation — laboratory certificates, lot records, pricing and company identity. Nothing on this page is guidance on human or veterinary use, dosing or health outcomes.
The interviewer had heard the story as internet rumour and asked whether it was true.
It's actually a true story. When I started the business in 2012 or 2013 … I kept the samples. Instead of one vial you got the entire kit of ten, so I just put them in the bag in case we need to reference the sample later on, and then I forgot about them for a decade.
It did degrade, but not in a manner that would affect much. You could tell it had been slightly degraded, but it would still work. A person won't know if they're getting 11 international units or 10 and a half.
And it's been in room temperature for a decade.
Those were sealed, lyophilized vials. Nothing had been added to them. That is the condition the rest of the room-temperature claim rests on.
Growth hormone is one molecule. The interviewer asked whether the same holds for the GLP compounds that now make up most of the lab's work.
We've done a lot of degradation tests with those. They're really stable, but there's stuff that you need to take into account. A properly made, undissolved lyophilized vial is going to be extremely stable even at room temperature. In fridge it's going to last you years. In freezer, I don't know, maybe decades.
The caveat he attaches is about manufacturing, not weather. One plant let something into its vials that should not have been there, and those vials lost their first few percent quickly before settling down.
If you tested the vial three days after manufacture … we see the same sample in a month, even if it's been stored properly, and it was 96%, because 4% degraded really fast. And then we saw it again in six or twelve months and not much else happened with the sample.
The interviewer offered a rule of thumb and he accepted it: if a vial tests around 99% when it reaches you, expect years in the refrigerator and decades in the freezer (24:25, 24:55). On the deep freezer the interviewer keeps his own stock in:
It's pretty overkill, but it's gonna last you a while. … I actually think the fridge would be plenty enough for most people.
Everything above stops applying the moment water goes in. Asked how long an opened vial should be kept, his answer moved from chemistry to microbiology.
Generally they last you longer than you ought to keep them. At some point after a particular amount of days or weeks you are at a higher risk of something growing in your vial, it getting contaminated with microbes, than it actually degrading.
It's not worth it to keep peptides over two to four weeks, I would say, because then you start to get something growing in it and it can cause local reactions. But the peptide itself is most likely still going to be okay after a month.
I would be pretty comfortable after a month if it's stored in a fridge, you're using aseptic technique, especially if it was sterile to begin with.
He would not advise six or eight weeks (40:08), and his practical fix is to stop the problem at purchase: get the vial size that fits the purpose (40:23), rather than one large vial that sits open for months.
| Vial state | Room temperature | Fridge | Freezer |
|---|---|---|---|
| Sealed, lyophilized (powder), properly made | Stable; a decade at room temperature cost his HGH samples a little potency, not function | Years | Decades, in his estimate; a research institute he worked with keeps peptides frozen for decades |
| Sealed, lyophilized, from a plant with a contamination problem | First 3–4% can degrade fast, then it stabilises | Same pattern: 99% at day 3, 96% at one month, little change at 6–12 months | Slows the same loss; does not undo it |
| Reconstituted (water added) | Not the question; the risk is growth, not heat | Two to four weeks is his advice; comfortable at a month with aseptic technique and a sterile starting vial | Not discussed |
Every cell is from the interview linked above (20:32–26:10 and 37:35–40:23); the figures are his lab's observations and estimates, not a published stability study. Where the vial came from matters more than where it sat: the 3–4% fast-loss case was a manufacturing defect.
A sealed vial that spent a summer afternoon in a mailbox is, on this evidence, in no worse shape than the growth hormone that spent ten years in a Slovak garage. The thing to check when a delivery arrives is not the temperature it travelled at but the paperwork it travelled with: a certificate for that lot, from a lab that will confirm it, dated close to when you bought. How to do that in a few minutes is in how to read a peptide COA. The handling question people actually argue about, shaking, is answered in the shaking guide, and the one they should argue about, what water goes in, is in bacteriostatic vs sterile water.
Storage is rarely what ruins a vial. The failures his lab actually sees are vials that were short or wrong before they shipped (about 5% of samples) and opened vials that grew something (3 to 5% fail sterility). Both are caught by the same habit: buy from a vendor whose certificates you can verify on the lab's own system, check that the lot on the certificate is the lot on your vial, and keep opened vials in the fridge for weeks, not months. A vendor that sells the right vial sizes is doing part of that for you.
Scoreboard order. The score reads documentation only; partner status is disclosed and does not move it.
Purgo Labs and MyPurePeptide are affiliate partners; we earn a commission on those links. Scores are computed without reading partner status, and the evidence behind every point is public on the scoreboard.
Sealed lyophilized vials do not need it for the stretch between delivery and use. Janoshik's founder says a properly made undissolved vial is extremely stable even at room temperature, lasts years in a fridge and in his estimate decades in a freezer, and he called a deep freezer overkill. The fridge is where he would keep them, not because room temperature is dangerous but because it is cheap insurance. Once water is added the answer changes and a fridge is the baseline.
His own evidence is a bag of reference HGH kits forgotten in his garage from the company's first years in Slovakia. Tested a decade later they had degraded slightly but, in his words, would still work; the difference was on the order of 11 units against ten and a half. For GLP peptides his lab has run many degradation tests and found them very stable. That is for sealed powder; there is no equivalent claim for reconstituted vials.
Not in his experience with lyophilized vials. He describes a research institute that keeps peptides frozen for decades without issue and puts the freezer estimate at decades for a properly made vial. He also says a minus-40 freezer is overkill and a fridge is plenty for most people.
His advice is not to keep it beyond two to four weeks, and he is comfortable at a month if it is in a fridge, handled aseptically and was sterile to begin with. The limiting factor is not the peptide breaking down; it is the chance of something growing in the vial, which can cause local reactions even when the compound is largely intact. He would not advise six or eight weeks. He also suggests the simplest fix: buy the vial size that matches the purpose so nothing sits open for months.
He describes exactly that pattern from one manufacturing plant: a contaminant got into the vials, the first three or four percent degraded fast, then the loss slowed to the normal rate. A 99% result at day three became 96% at one month and barely moved by six to twelve months. It is a manufacturing problem, not a storage one, and it shows why a certificate dated close to your purchase is more useful than one from the day the batch was made.