Promoting muscle recovery in your finger primarily relies on targeted hand therapy rather than medication. I recommend consulting a physical therapist for specific finger-strengthening exercises, such as using therapy putty or resistance bands. For nutrition, ensure you eat enough protein to support muscle repair. While no specific medicine regrows finger muscles, general supplements like Vitamin D, Omega-3 fatty acids, and creatine can aid overall tissue recovery. Please consult your doctor first to identify the root cause of the muscle loss, such as nerve compression or disuse, so they can guide your rehabilitation safely.