Hello, i just want to ask what contraceptive is better for my girlfriend. she's 23 year old. thank you.

Don't have a clue: The "best" for anyone is whatever is determined after a good medical history, review of present health issues & meds and an understanding of how/why it is being used. There are dozens of "pill" choices that may or may not work well with a particular person. In short, you find this out by working with a health professional over several months.