What happens if I don't follow the proper Botox schedule?

I'm getting Botox, but I'm a bit confused about the timing. I was told to get it every 3 to 4 months, but I've missed my appointment a few times because I've been busy. I was wondering what the difference is: do my muscles develop again when that happens, or is the effect just gradually wearing off?

I’ve heard that getting Botox too frequently can lead to resistance, but I’m not sure if that’s true. I’m also wondering if getting it earlier than the scheduled interval is actually harmful or if it doesn’t matter.

I heard that the Botox treatment cycle varies by area, so I would like to know how much the recommended intervals differ for the forehead, jawline, and nasolabial folds.

It would be really helpful if those of you who have been sticking to your Botox schedule for a long time could leave comments on how you manage it and what changes occurred when you missed a cycle.