Reconstituted Reta - what's the latest on shelf-life?

I see your point. I already use pens for my other peptides, but technically you're swapping needles and moving liquid back and forth each week, so it may not stay quite as clean as a sealed vial. Just a guess though.

Running filtered peptide into a clean pen cartridge is about as sterile and durable as it gets. That's just my rough take.

I'd agree, but the number of times you poke the stopper becomes the real limit. Daily dosing would mean 90 pokes, which seems excessive. I'd cap it at around 20 pokes total, ideally under 10.

The rubber seal on a pen cartridge is the same material used in vials.

Good observation. The 90-plus-day figure was calculated around weekly shots only.

True, but the other end of the needle sits in your body while liquid is connected, so backwash happens. It showed up in about a third of the insulin pens tested, and those have lots of preservatives plus an official beyond-use date longer than 28 days.

Does anyone have instructions for vial spikes that claim they keep a vial sterile past the usual 28 days? The bigger hole they make in the self-sealing stopper didn't seem ideal from a physical standpoint, and they need to match the right stopper or they can push it in and let contamination in. Not every spike is a closed-system device, and even some branded ones only claim seven days. They can be sanitary for a while if they are true closed-system types, but they may also create a weak point with a short life. How much any of this matters for subcutaneous use versus IV is another open question. I'm curious because pharmacies don't seem to recommend them.

One study found backwash in 5.6 percent of insulin pens. Something went wrong in those cases. Still worth keeping in mind.

There are ways to use pens that raise the chance of backwash. Reusing needles is common even though the official advice is no more than six times, and leaving the needle attached instead of removing it right away also increases risk. It's not surprising a hospital following every rule would see lower rates, yet the number was still that high. Similar work shows a small percentage chance of contamination each time a vial is punctured. General literature searches turn up these studies, often from outside the US.

You can obtain a year's worth of maximum-dose tirz quite inexpensively, so is that really a worry?

That sixty-day figure applies to already mixed product. You can purchase unmixed vials and store them for years.

I understand that. What I'm saying is the material is inexpensive enough that I doubt any seller would risk their reputation over a few extra dollars a year. Sixty days is also roughly double the most cautious timeline people usually follow.

It won't be. The thread will sink and the same question will pop up again in a week or two. I asked the identical thing about survo once.

I bought some 120 mg vials recently because they were very cheap. I'm currently splitting them among five people including myself. My main concern is the lack of a COA for these larger ones, though plenty exist for the 60 mg and smaller sizes. I'll have some fun reconstituting, measuring, splitting, and labeling them.

I used to think puncture count would limit things, but type-1 diabetics often pull multiple daily doses from the same vial for a full month, which can exceed 100 punctures. Still, I wouldn't personally go past about three months or roughly twelve punctures on one vial.