My skin elasticity has reached its limit with just basic skincare, so I would like to know the features of collagen boosters and the recommended frequency.

As I get older, my skin feels like it is generally thinning and sagging, so I feel like relying solely on cosmetics has its limits. I am considering trying a collagen booster. I understand that a collagen booster is essentially an "injection that replenishes collagen deep within the skin over time," but there are so many types and the explanations are full of technical jargon that it feels a bit difficult for a layperson to understand. Therefore, rather than focusing on complex principles, I would appreciate it if you could summarize the key features of collagen boosters in a very simple way.

There are two main things I would like to know. First, should I understand that collagen boosters provide a gradual increase in elasticity and volume over several months, rather than the immediate "boosting" effect seen with fillers? Second, regarding the recommended number of sessions and intervals for collagen boosters. I have often heard that a first course typically consists of 3 to 4 sessions at 4-week intervals, and I would like to know if that is a reasonable baseline considering my age and current skin elasticity. It would also be helpful for my decision if you could explain if it is common to receive a few additional treatments for reinforcement between 6 months and a year later.