According to this document, NMN may include the following 7 major health benefits

1. Brain

Enhances cognitive focus.

2. Vascular System

Increases neoangiogenesis, capillary density, and blood flow.

3. Liver

Improves liver function and reduces liver fat.

4. Muscles

Reduces atrophy, enhances mitochondrial function, and increases physical activity.

5. Pancreas

Improves / supports healthy metabolism.

6. Adipose Tissue

Lowers dyslipidemia.

7. Inflammaging

Reduces inflammation and improves immune cell function.

Reference: Recent research into nicotinamide mononucleotide and aging, Nature Portfolio