The Julia Ruffin Project grows and researches papaya leaves for use as a medicinal tea. There is a noted difference in the amount of alkaloids in a young papaya leaf.
There is also a big difference in taste. The young leaf tea is not bitter, and has smoky hints with a distinct smell of fresh and tantalizing unique to the herb.
In the photo, brewed young leaf tea is to the right, a hint of bright yellow, and next to the signature bright green dried and cut leaves.