When will the double chin lifting effect appear?

Hello. Recently, my weight has remained the same, but the skin under my chin has noticeably sagged and swelled up, causing me a lot of stress every time I look in the mirror. I suspect the sagging is worsening because my skin has lost elasticity, so I've tried using home care rollers and bands, but I haven't seen any noticeable changes.

So, I am looking into dermatological procedures to get proper care before it is too late. After doing some research, I found many reviews stating that double chin lifting lasers or injections are effective for sagging skin and contouring like mine, so I am planning to get a proper consultation.

Since I have to manage my schedule while working, I would like to plan the procedure in advance. I am wondering how often I typically need periodic maintenance after a double chin lift to maintain the effects.

I would also like to know how long it usually takes after the procedure to visually see the jawline becoming more defined. I would appreciate it if you could let me know the average treatment cycle and the time it takes for the effects to appear for a typical double chin lift!