My 2yo vial from before I switched to undecylenate is still clear, I would still use it.

I have one, used it for 7 months so far, color still the same. It depends, if it feels like the Estradiol enanthate has gone bad (color change) or there is something inside that has probably compromised it, I would throw the vial away.

Rubbing alcohol pad on it before and after use. I always keep the vial away from the light, and keep it in a upright position (not when using). I try to pierce the cap not in the same place. And I try to keep it under 25°C (Which may have not been entirely possible).

I may have missed something but it is something that has been recommended to me

Look, with perfect conditions the vial should last until empty. I didnt mean to make you think that you cant empty it.

As with everything in life, its all about risk tolerance. Especially with diy, how much risk are you personally willing to accept? If you feel that you can empty it, then i cant and wont tell you you cant.

Do look for the things i mentioned in other thread, because that is important. But i made that thread because i had the same issue. I didnt want to throw that vial away. BUT i wasnt as careful as i am now with that particular vial, so i have not injected from it again. My second vial i have pushed past the 28 day thing, but thats because im sure i was careful. I guess my risk tolerance is low, i have a case with sanitized caps for the vials, wipe everything down before and after with alc pads, and i still wont go past 6 months. But thats also cause ill empty it before then

So ultimately, because youre doing diy, its up to you. Definitely research, like you have been, and feel free to ask questions. I want you to be able to empty your vial, and im rooting for you. I was just trying to tell you the things i heard, and am living by now. ❤️❤️

From the website for anybody who needs to know ingredients:

The active ingredient is estradiol enanthate (400 mg). Inactive ingredients are benzyl alcohol (2% w/w) as a preservative and MCT Oil as the carrier. Does not contain benzyl benzoate.

Edit: My quick internet search can't find any studies looking at pharmaceutical use past 28 days. I remember reading a super informative post about benzyl alcohol a long time ago.

Since you're talking about using it for longer than 30 days, I'd store it in an air tight container in the dark and toss in oxygen reducing packets to eat up all the oxygen in the container. Benzyl alcohol & estradiol both oxidize anyways.

Edit 2: @sidalsolgun@lemmy.ca quotes https://pghrt.diy/#S5.SS24

5.24 How long until a vial expires?

A sealed vial could last for years without issue if it is stored at stable temperatures away from the light. Concerns with age are primarily carrier oil oxidation assuming that the vial was sterilized as it should be. A punctured vial that has a preservative in it (see Question 6.17) should last at least a year or whatever the life time of the vial is (i.e., how long until you use it all). The “discard after 28 days” listing on vials is simply the minimum requirement for how long manufacturers must guarantee sterility, not the maximum shelf life.

Here says minimum 1 year:

https://pghrt.diy/#S5.SS24