You use it until your problem is resolved, that can be very different for different people. People fixing digestion and leaky gut typically resolve pretty quickly, usually within a couple weeks. When I use it for my elbow tendonitis when it acts up and won’t stop It usually starts behaving again within a week. When I really push my shoulders and they start it’s typically a vials worth to get them back, but relief typically begins within a week.
The go-to dose is usually 250mcg 2x/day. I personally use 500mcg 2x/day, but I’m also a 230lb dude.
The issue with collagen peptides is that you get everything they give you with all complete proteins. Collagen peptides are a protein with the tryptophan missing. So whether it be real protein or just a protein powder, you’re getting all the same benefits (and) you now have real complete protein that your body can use otherwise. The difference that some nitpick is the amino concentration of glycine which is high in the collagen peptides, which is very cheap to supplement in otherwise. Way more bang for your buck to just use a real protein powder and then add in glycine (if) you even wanted to.