If you're worried, you could try sterilizing them yourself. Steam sterilization in a pressure cooker is an option. It's not a guarantee, but it's better than nothing. Make sure the plungers are loose so the steam can reach all surfaces. Indicators are often unreliable. A medical supply vendor would be a safer bet.
I got a bunch during a sale, the listing said sterilized, but the indicator was the wrong color! So I loosened the stoppers and steamed them for a while, then baked to dry them. The indicator did change after that.
I just pushed them in a little bit to make them loose. The first time, I didn't even touch them, and they popped out during the drying stage. I just ordered a vacuum jar someone suggested to suck them out first.
I bought three pens from a certain website and one broke already! The plunger stopped working. Guess you get what you pay for. I'm buying better ones now. Any recommendations?
Not that it means anything about it working, but the earlier version is often recommended over the later one. The V2 was supposed to be improved, but...
I'm tempted to switch back to insulin syringes and just inject each peptide individually. It's a hassle and uses a lot of syringes, but maybe it's safer.