Tirz shelf life after reconstitution (NaCl, pH, etc.)

[SirBonbon]

I've been wondering about shelf life of reconstituted tirzepatide. Most of us use normal BAC water, some choosing the version with added NaCl. I haven't seen much discussion about stability though, or any mention of buffered solutions.

Since Mounjaro pens achieve great shelf life, reconstituted tirz sure can stay fine for months. However, as opposed to standard BAC water, the pens contain phosphate buffer (at 5 mM, bringing pH to 7.0) as well as NaCl (at 140mM, or 8.18 mg/mL), both contributing to peptide stability (as they state in their patent aplication https://patents.google.com/patent/WO2024086601A2/en).

From my understanding of the patent application text, NaCl considerably improves stability, and buffering might actually be necessary for longer storage (tirz degrades in lower pH, don't know how fast though).

I wonder though how important this actually is for peptides reconstituted from powder, refrigerated and used up within several weeks or months. Has anyone stumbled on any clues? Have you noticed if the solution seems less potent with time?

 

[Garbo]

I've been wondering about shelf life of reconstituted tirzepatide. Most of us use normal BAC water, some choosing the version with added NaCl.

Huh, I feel like I've read enough posts about bac water to last two lifetimes, and yet I've never come across anything about solutions with added NaCl.

ps. Just my experience, been reconstituting tirz for a few years and I never, ever worry about its shelf life.

 

[raw_oyster_eater]

maybe filter it if its really old if you want to be cautious

 

[Yankeegurl_LQJ]

I've been wondering about shelf life of reconstituted tirzepatide. Most of us use normal BAC water, some choosing the version with added NaCl. I haven't seen much discussion about stability though, or any mention of buffered solutions.

Since Mounjaro pens achieve great shelf life, reconstituted tirz sure can stay fine for months. However, as opposed to standard BAC water, the pens contain phosphate buffer (at 5 mM, bringing pH to 7.0) as well as NaCl (at 140mM, or 8.18 mg/mL), both contributing to peptide stability (as they state in their patent aplication https://patents.google.com/patent/WO2024086601A2/en).

From my understanding of the patent application text, NaCl considerably improves stability, and buffering might actually be necessary for longer storage (tirz degrades in lower pH, don't know how fast though).

I wonder though how important this actually is for peptides reconstituted from powder, refrigerated and used up within several weeks or months. Has anyone stumbled on any clues? Have you noticed if the

I've been wondering about shelf life of reconstituted tirzepatide. Most of us use normal BAC water, some choosing the version with added NaCl. I haven't seen much discussion about stability though, or any mention of buffered solutions.

Since Mounjaro pens achieve great shelf life, reconstituted tirz sure can stay fine for months. However, as opposed to standard BAC water, the pens contain phosphate buffer (at 5 mM, bringing pH to 7.0) as well as NaCl (at 140mM, or 8.18 mg/mL), both contributing to peptide stability (as they state in their patent aplication https://patents.google.com/patent/WO2024086601A2/en).

From my understanding of the patent application text, NaCl considerably improves stability, and buffering might actually be necessary for longer storage (tirz degrades in lower pH, don't know how fast though).

I wonder though how important this actually is for peptides reconstituted from powder, refrigerated and used up within several weeks or months. Has anyone stumbled on any clues? Have you noticed if the solution seems less potent with time?

According to Janoshik it doesn't really matter which of those solutions you use for reconstitution. Either one should last months, not wks. There is a super informative Q&A with him on Peppys where he pretty much shoots down a lot of common things that people believe about reconstitution, solutions, degradation, fragility, manufactures/vendors and so much more.

 

[SirBonbon]

I've never come across anything about solutions with added NaCl.

It's basically saline with added benzyl alcohol (image below). The idea is that by it being isotonic there's less cellular damage and less discomfort/pain. In this case, Lilly claims that proper NaCl concentration also improves tirz stability by balancing peptide oligomer size (whatever the practical impact of this actually is).

I never, ever worry about its shelf life

Well, I'm on 2mg at the moment, and if it so happens that I can stay at this dosage, a T40 vial would last me almost half a year. I'd feel bad if it degraded on me, especially if it's preventable.

maybe filter it if its really old if you want to be cautious

Filtering would work for bacteria, sure, but the issue I'm trying to figure out is peptide degradation. The little materials I've found pointed to tirz being e.g. sensitive to pH (hence the buffering).

There is a super informative Q&A with him on Peppys

Oh, I'd be very interested to read that! Haven't heard about Peppys before. Unfortunately since it's a private community, I can't...

Also, from what I understand, some peptides are inherently more stable in solution than others, so it might very well depend on the peptide.

 

[Mykrodot]

It's basically saline with added benzyl alcohol (image below). The idea is that by it being isotonic there's less cellular damage and less discomfort/pain. In this case, Lilly claims that proper NaCl concentration also improves tirz stability by balancing peptide oligomer size (whatever the practical impact of this actually is).


Well, I'm on 2mg at the moment, and if it so happens that I can stay at this dosage, a T40 vial would last me almost half a year. I'd feel bad if it degraded on me, especially if it's preventable.


Filtering would work for bacteria, sure, but the issue I'm trying to figure out is peptide degradation. The little materials I've found pointed to tirz being e.g. sensitive to pH (hence the buffering).


Oh, I'd be very interested to read that! Haven't heard about Peppys before. Unfortunately since it's a private community, I can't...

Also, from what I understand, some peptides are inherently more stable in solution than others, so it might very well depend on the peptide.

If you want to join Peppys use the search here with “join Peppys”and you should be able to figure out how to join. There are a few breadcrumbs to be found. One of Peppys admins stops by pretty regularly to check messages. You will find her!

 

[SirBonbon]

If you want to join Peppys use the search here with “join Peppys”

Hehe, never occured to me to do that. I'm in, thanks! Looks like a trove of info. There goes my Sunday...

 

[GimmeABreak]

If you want to join Peppys use the search here with “join Peppys”and you should be able to figure out how to join. There are a few breadcrumbs to be found. One of Peppys admins stops by pretty regularly to check messages. You will find her!

She just posted an open invite to Peppys on this site a couple of days ago. Open invites to Peppy's are a rare event.

I checked with GK to make sure it was legit (and not someone posing as GK) and she said she would leave the invite open until a certain number of new users joined. She didn't specify how many.

 

[Mykrodot]

She just posted an open invite to Peppys on this site a couple of days ago. Open invites to Peppy's are a rare event.

I checked with GK to make sure it was legit (and not someone posing as GK) and she said

Hehe, never occured to me to do that. I'm in, thanks! Looks like a trove of info. There goes my Sunday...

SirBonBon, please send me a dm.

 

[scarywood75]

I use BAC saline personally for the following reason:
- I can get 10ml bottles which means less waste and single use so I feel more safe about introducing pathogens.
- for me and others that tried it, comfort is much better, you don't feel at all the liquid like the real deal. Before when I was using plain BAC, I could feel the discomfort.
- it's not even more expensive than plain BAC

These applies to me, but your mileage may vary