Does the effect of frown line Botox last?

I have been getting regular, affordable Botox injections between my eyebrows, but it seems the effects are wearing off. I used to get them two or three times a year, but now I find myself getting them three or four times. The effects are visibly diminishing... What procedure would be best for me going forward?

I also found out about "Skin Botox" in addition to the frown line Botox I'm currently getting. It's not the same Botox; I heard it's injected shallowly into the surface of the skin to help with pores, fine lines, and oil control. I've read several reviews saying it's really good, so is that true?

I would like to try it out.

I am even more curious now that you mention it doesn't just tighten the muscle layer. Since it focuses on refining skin texture and subtle elasticity improvement rather than a dramatic facial transformation, I think it might be a good fit for me. I would like to know the cost, treatment time, and recovery period.

If there is a significant difference between regular Botox and Skin Botox, I think it is time to switch to Skin Botox.