is there any way to fix a thin upper lip without filler or surgery?

[jeb98]

^

 

[Montenigger]

brush with toothpaste and toothbrush

 

[medialcanthus]

suck me 3x12

 

[jeb98]

suck me 3x12

good one

 

[Zeekie]

^

very technically speaking? No. But, as the guy above said, exfoliating them can improve their appearance and maybe make them a bit more plump? But that's perhaps not as radical of a change as you'd wish.