How do you properly store the powder peptides & how long do they last?

I’ve been on Tirz for a year. I’ve been at my goal weight for 6 months and would like to lower my dose but don’t want the food noise to come back. I’ve been on 9mg a week for the past 3 months. I inject 3mg 3xweekly. I was thinking about replacing one 3mg injection with a 2mg Reta. Has anyone tried taking tirz and Reta?

Had someone reach out in Nebraska and they don’t allow purchasing of syringes through Amazon. I know Massachusetts and I think California is the same way. Can anyone provide Alternative sources for sryinges?.

What’s everyone’s favorite size for pen needles? I got 4mm because that was googles recommendation and the easiest accessible (Walmart), however I’ve been getting bumps/welts from peps that didn’t previously cause them. The pens came with a 6, 8, and 10mm to try, but when I Google it they say that’s too deep, but I’m feeling like that may help? What’s everyone’s experience?

Will be 50 yrs old next year - I just got blood test results back and have lower testosterone levels than average. Has anyone injected Testosterone? And if so how did you figure out what dosage was best?