How many Rejuran sessions would be effective?

Lately, my skin feels generally dry and lacks elasticity, so I am looking into Rejuran. In particular, my skin texture isn't as smooth as it used to be, and fine lines are starting to appear, so I want to take care of my skin to make it firmer.

I looked up reviews for Rejuran, and while some people say their skin became moisturized and texture improved after just one session, there are also many comments saying that you usually need to receive several treatments to feel the proper effects. So, I am wondering how many sessions are actually required to see satisfactory changes.

If I am receiving this for the first time, I am wondering if it is okay to try one session first to check the skin reaction or effectiveness before getting additional sessions, or if it is better to receive multiple sessions at regular intervals from the start.