Peptide degradation from repeated warming of reconstituted vials

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Rickcaps

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I've been mulling over what happens at the chemical level each time a reconstituted peptide leaves the fridge and warms up to room temperature for an injection. A few things I keep wondering about:

1. For those using pens, the routine means warming it to room temp before every single pin, then putting it back in the fridge afterward. Across 20 or 30 of those cycles, how much degradation would the peptide actually accumulate?

2. What's the method most people rely on for pinning — bringing the vial up to room temperature first, then drawing and injecting?

Or

Do you simply pull from a cold vial, let the syringe sit out at room temp for about an hour, and then inject? That approach would leave the original peptide with far less exposure to temperature swings.
 
Honestly, in 99% of cases I pull from a vial that is still cold and inject right away. There have been a handful of occasions, though, when I drew first and carried it from the kitchen into the bathroom so I could inject straight after showering.
 
I pull what I need out of the vial and let it warm up inside the pen.

That comes from my chef mindset. When something has to be kept cold, you only remove the portion you're using and leave the remainder in the conditions it requires.

Same idea as pulling a chicken breast out, letting it reach room temperature, slicing it in half, and returning the other half to the fridge. Lol.😂
 
I've always pinned my peps straight from the fridge, never waiting for them to reach room temp. They still work well for me. In all my time as a nurse, no medication I've handled has ever required that step.
 
I used to share that view, but at this point I figure it makes little difference. Whether it's left out for a minute or an hour, it should still work. My hunch (and that's all it is) is that bright light does more harm in a short window than sitting at room temperature does.
 
Same here — I take it right out of the cold. After pulling from the refrigerated vial, the vial goes back in, and the syringe usually waits no more than 2 minutes. Whether that’s actually correct, I couldn’t say; my reasoning was that getting it into me quickly after the fridge might be preferable?
 
My routine is to pull with a syringe while it's cold, wait roughly 5 minutes, and then inject. Nothing has ever gone wrong for me.
 
From what I recall, there's a single pep that draws more burn complaints when it's cold (can't remember which one). For GLPs and nearly every other pep, though, injecting while cold ought to be completely okay. A really large dose might bring some discomfort, perhaps, but that has never been a problem in my experience.
 
Draw it out and inject... finished within 60s.

Just so you know: I've still got a fair amount of padding left to shed, so I can't really say how this goes for folks who are lean 😇
 
With Mounjaro, injections are given cold, exactly how the manufacturer instructs.

Pens are taken straight out of the fridge for use.

For aod and tesamorelin, a thinner needle means a slower push when the solution is cold.

The same goes for ss31 — it appears prone to recrystallizing when a thinner needle is paired with a smaller amount of Bac water.
 
I draw with syringes rather than pens, yet I inject while the vial and syringe are still cold.
 
Rickcaps said:

I've been mulling over what happens at the chemical level each time a reconstituted peptide leaves the fridge and warms up to room temperature for an injection. A few things I keep wondering about:

1. For those using pens, the routine means warming it to room temp before every single pin, then putting it back in the fridge afterward. Across 20 or 30 of those cycles, how much degradation would the peptide actually accumulate?

2. What's the method most people rely on for pinning — bringing the vial up to room temperature first, then drawing and injecting?

Or

Do you simply pull from a cold vial, let the syringe sit out at room temp for about an hour, and then inject? That approach would leave the original peptide with far less exposure to temperature swings.
Click to expand...
If you allow it to warm up to room temperature across 30 cycles, the resulting degradation is likely so slight that you would never detect it.
 
Rickcaps said:

I've been mulling over what happens at the chemical level each time a reconstituted peptide leaves the fridge and warms up to room temperature for an injection. A few things I keep wondering about:

1. For those using pens, the routine means warming it to room temp before every single pin, then putting it back in the fridge afterward. Across 20 or 30 of those cycles, how much degradation would the peptide actually accumulate?

2. What's the method most people rely on for pinning — bringing the vial up to room temperature first, then drawing and injecting?

Or

Do you simply pull from a cold vial, let the syringe sit out at room temp for about an hour, and then inject? That approach would leave the original peptide with far less exposure to temperature swings.
Click to expand...
I pull the pen or vial out, inject right away while it's still cold, then return it to the fridge. All 6 of my peps never get a chance to warm up. Keep in mind that benzyl alcohol is more effective at room temperature. Bacteria worry me more. From everything I've read, peptides hold up well under 80 degrees. If you handle it poorly, you might drop 1% potency each month => the effect is minimal. My compounding pharma label said my glp1 could sit at room temperature for 3 weeks (a big ++ for travel). Keep it out of sunlight, away from heat, same as Bac.
 
At first I would wait for it to reach room temp, but eventually I got curious about how a cold shot would feel. No difference stood out to me. These days I just inject it straight from the fridge. Perhaps larger mL volumes are where it matters.
 
Honestly, the idea of allowing it to reach room temperature has never once crossed my mind. I just draw it up and inject. The chill has never caused me any soreness or weird feeling.
 
For us, leaving it out so it reaches room temperature is much more comfortable!! We tested the alternative and could tell it made a difference. It was noticeable either way. This is with a pen using 32g 4mm tips
 
Could the chilly discomfort depend on how long the needle is? My 1/2" needle puts me further into the fat layer, where there are fewer nerves, and not the type that sense pain. A short needle only just reaches the fat, sitting right beneath the skin. Perhaps the cold is picked up by the nerves in your skin.
 
Once it's in a really thin insulin syringe, my guess is the temperature would match the surroundings pretty fast, since there's so much surface area relative to the volume. I've always injected right away and it has never felt cold to me at all. If it were still fridge-cold, I'd think you would feel some chill on injection, at least a little.
 
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