Or you could just eat some chicken. Or salmon.
Since this thread is full of AI quotes, here's another one:
Hydroxyproline is most abundant in animal products, particularly meat, bone meal, poultry by-product meal, and salmon proteins. It's also found in smaller amounts in some plant-based foods like legumes, beans, lentils, and soy products. Alfalfa sprouts also contain hydroxyproline, but in limited quantities.
Here's a more detailed look:
Animal Products:
Meat and bone meal: These are rich sources of hydroxyproline.
Poultry by-product meal: Another good source of hydroxyproline.
Salmon proteins: Salmon also contains hydroxyproline.
Small, whole fish (sardines, herring): These can be a source of hydroxyproline.
Organ meats (liver, kidneys): These are also good sources.