Clock one: days
Swelling in the cheeks arrives fast and sits high. That last part is what unsettles people, because volume placed on the cheekbone plus fluid on top of it reads as considerably more than was actually put in.
The first evening is puffy and firm. Day two is usually the peak rather than day one, which catches out anyone expecting a straight line downhill. From day three it eases noticeably, and by the end of the first week most of the fluid has gone.
Bruising, if it happens, shows by day two. Cheeks bruise less often than lips but when they do it can track downward with gravity and appear somewhere you weren't treated, which is ordinary and looks worse than it is.
What helps: staying upright the first evening, sleeping propped and on your back, skipping alcohol and hard exercise for a day or two, and keeping heat off your face. What doesn't help: pressing on it to assess progress, which is the most common instinct and the least useful one.
