How to optimize free testosterone level.

Doctor, I recently completed a comprehensive male hormone panel and would like your guidance on optimization. I am 26 years old and generally healthy. Key results: Total Testosterone: 544 ng/dL Free Testosterone: 6.78 pg/mL SHBG: 21.1 nmol/L LH: 3.39 mIU/mL FSH: 3.94 mIU/mL DHT: 445 pg/mL Androstenedione: 0.95 ng/mL Vitamin D: 50.2 ng/mL Vitamin B12: 316 pg/mL From my understanding, SHBG is in an optimal range, androgen conversion (DHT) appears normal, and LH/FSH suggest an intact and satisfied hypothalamic–pituitary–gonadal axis. However, free testosterone seems relatively low for my age despite these findings. I would appreciate your opinion on the following points: Does this pattern suggest a central set-point regulation rather than a production or binding issue? Is my current free testosterone level adequate for a healthy 26-year-old, or is there a rationale to aim for a higher age-optimized range? Are there evidence-based lifestyle or medical strategies to improve