I appreciate the impulse to "share" GLPs with others you care about, but significant hazards lie that way. Not just the ever present risk of them getting ripped off (and blaming you), but now you bear potential responsibility for any weird medical issue in the future, "I got small intestine cancer! It's from that counterfeit Chinese drug you told me it was ok to inject!".
So think twice. At the least, text or email (so it's in WRITING for later reference), "This is what I use, I get it from here. I think it's ok but be sure to do your own homework on potential risks. If you have any questions I'll be happy to help." and let them acquire it on their own.