Bella's results are definitely not due to threads of any kind - you cannot achieve her face with threads alone.
I've had ... oh I think probably 8 threads on each side of my face over the last few years. The results are instant and noticeable, but not a miracle worker. I still workout very intensely 4-5 times per week with a trainer and eat a very strict diet; that is where the real results come from. The threads are a nice touch just to keep everything tight in addition to a healthy diet & exercise.
I think that anyone trying to achieve a look like Bella's would have to have an actual mini or full face lift, IMO.
Anyhow, for anyone interested, yes they are worth it. They DO provide tightening and lifting, but it is subtle for sure.
The actual procedure is not pleasant - full disclosure. I know there are different methods. The method that I have had done involves a small "dot" incision made in the face, then a micro canula with the actual thread are "threaded" into the face. The canula is pulled back out, leaving the thread in place, which is then pulled taut. No lie - it is a little painful. If any of you have had cheek fillers, it is more painful than that. I would say about a 4-6 out of 10 depending on your tolerance. The part that hurts is when the canula needs to "tear" through the fibrous portions of your tissue. Luckily, the canula has lidocaine that is simultaneously injected while moving through your tissue, so it does soften the pain a little. Also good news, the tearing is literally one second each time with no residual pain.
The downtime is minimal. You'll definitely be sore for a few days after, but when done properly, you should not see swelling. Maybe a little, but nothing significant. If you are a side or stomach sleeper, just be prepared to not sleep on the side of your face as it will definitely be tender.
Outside of that? Nothing bad to report - I would definitely give the threads a try but do not expect huge results. Super subtle, but worth it IMO. Hope this helps someone!