How much do under the muscle butt implants drop over time? (photos)

If this is a longevity question, over time buttock implants can drop or thin out tissues for several months.  The buttock does have the tendency to soften as spasm and swelling decrease and the shape may change.  I am not sure the the buttock ever gets larger with time.  Usually, as the swelling resolves, the size becomes smaller.The key to this surgery is to select an implant that is not so large that the muscle cannot cover it reliably. You want a nice result, but you want to avoid the complications (need for removal, infection, extrusion, fluid collection, implant migration, implant visibility, and capsular contracture among others). Studies have demonstrated that sizes above 350 cc have a greater rate of complications.Kenneth Hughes, MD, Board Certified Plastic SurgeonLos Angeles, CA

I find that the implants sit a bit high initially and then settle down into the pocket with time.  Best of luck.

when performed in an appropriate intramuscular pocket, the implants are usually stable and won't move; if you choose the wrong implant size, then it will break through the muscle fascia making the implant pocket larger and more prone to movement.