Injectable collagen isn't really a thing. Hyaluronic acid can be injected into joints though, especially after forty. Collagen needs high amounts like ten to twelve grams daily plus vitamin C since it supports synthesis. Powder ends up the cheapest way.
I'm just starting out losing weight and recall hair thinning happened in past efforts. Already taking a multi and biotin. Considering adding collagen as well. Anyone using an injectable peptide version or do most stick with powder and capsules? I'd probably try powder or capsules but open to other ideas.