Methods and compositions for enhancing or maintaining fertility

A method for increasing, enhancing, or maintaining fertility in a human being in need thereof, the method comprising:

• providing an oral nutritional supplement unit dosage form, wherein the oral nutritional supplement unit dosage form comprises about 1 mmol L-arginine, about 1 mmol oxo-proline, about 2 mmol L-lysine, about 1.5 μmol N-acetyl L-cysteine, about 2 μmol L-glutamine, and about 125 μg schizonepeta (aerial parts) powder;
• and
• orally administering an effective amount of the nutritional supplement to the human being.