What are the actual effects and pain levels of Rejuran like?

Lately, my skin has been generally dry and I have more fine lines, so I am considering Rejuran.
I'm interested because I heard it's very effective among skin boosters, but I'm worried because I heard it's very painful.
I am also curious if it is possible to resume daily life immediately after being hit.
I want to know if it definitely helps improve skin texture or dryness from within.
I am also curious how many times it takes to see visible effects.
I would like to hear opinions from those who have experienced it regarding whether it is a procedure that is suitable for consistent use.