Is Starship 100% reusable?

Could you please clarify for me if Starship is indeed 100% reusable, or are there any components that are considered expendable or need to be replaced after each launch? I'm particularly interested in understanding the level of sustainability and cost-effectiveness associated with its design, and whether it truly represents a step forward in the pursuit of fully reusable spacecraft. Thank you for your time and expertise in this matter.