I use 5mg every 5 days, should I buy 15mg or 30mg vials?

Freezing the powder is fine, but the instructions say not to freeze the liquid after reconstitution. A quick search confirms the same.

Yeah thanks, I think that is the way for me because it sounds right.

I have to disagree. More searching shows tirzepatide has no issue with freezing. I work with LC-MS/MS and confirmed the potency stays the same. This applies only to tirzepatide, not every peptide. Look for the studies if you want to check.

You did your homework. Well done.

Nice that you work with LC-MS/MS. Would retatrutide behave differently from tirzepatide when frozen since both have 39 amino acids? I was planning to reconstitute and freeze a vial of retatrutide too. Is the structure more complex?

That comes across as condescending, which means talking down to someone.

I am not arguing with your test results on chemical potency. The problem is that the official guidance does not recommend freezing because stability does not equal safety. Tests can show the molecule is there but do not check aggregation, sterility, or freeze-thaw effects that matter for injections. You can do what feels right for you, but saying it is no problem goes beyond the clinical recommendations.

LC-MS/MS with Orbitrap can also show aggregation and degradation. If you reconstitute and filter correctly into sterile vials, sterility is not an issue. I used to think the same about not freezing, but studies specific to tirzepatide plus my own tests on frozen vials showed no problems. Not every peptide aggregates the same way. I only freeze once and do not refreeze after thawing.

That was not my intention. Sorry. I tested my own tirzepatide after reading studies because I take it. I plan to test retatrutide later too. Same number of amino acids does not mean the same physical behavior. It depends on the types of amino acids and bonds. When I test retatrutide I can share the results.

I didn't aim for that result. Sorry about it.

Do you store the mixed liquid in the freezer after preparing it?

Yes, but only one cycle. After I take the second vial out of the freezer I do not freeze it again. There are studies showing several cycles cause only minimal degradation, and others on storing reconstituted tirzepatide at room temperature. I can link one.

I did not read it as condescending at all. I cannot see how it would be taken that way. It might be picky of me to note that the phrase should be did your homework instead of made your homework.

Yes, if you could share what you find about freezing retatrutide later that would be great.

Sorry, that was unclear. I should have included the earlier post that together sounded rough. It is all good.

Good point. In these groups English is not always the first language, so a bit of extra patience helps when wording seems off.

Great point. I apologize and will keep that in mind.

I have been freezing both tirzepatide and retatrutide and they still feel strong after thawing. The science says it is a bad idea, but in practice it seems fine.

Same thing happens with foamy or aggregated HGH on other forums. People use it years later with no issues. Same with splitting orodispersible tablets. Not officially recommended, but no personal problems.

Just because something has not been studied does not automatically make it a bad idea. A bad idea is when studies show harm and people still do it. For tirzepatide there is already some evidence that freezing after reconstitution is not a problem. Do you agree?

I also keep some 15 mg and 10 mg vials handy for travel.

This is big news to me. If I had known instead of reading over and over never to freeze after reconstituting, I would have bought the big lyophilized vials, reconstituted, and split into many small vials like you are doing. Thanks for the info.

I agree completely. Most mainstream sources and even chatbots warn against it strongly. I do not always phrase things perfectly, but I am on the same side as you.

That is what I do. I get 120 mg bottles of tirzepatide and 60 mg bottles of retatrutide and feel better freezing them than leaving them in the fridge for months.

You can freeze the reconstituted product? Interesting. I thought that was not allowed. Learn something new.

For now everything I said applies only to tirzepatide. It might work for retatrutide too but I want to see more testing first.

I only test one or maybe two products. Reconstituting when needed is simpler for me. That level of planning does not save me time. Glad it works for you though.