Average testosterone by age (ng/dL)
Overview
Male fertility does decline with age, though less dramatically than female fertility. From approximately age 35, testosterone falls more rapidly, sperm DNA fragmentation increases, and motility and morphology worsen measurably. The hidden danger today is that age compounds an already severe baseline crisis: today's 40-year-old begins with dramatically lower testosterone than a 40-year-old in 1980. Age-related decline starts from a far weaker foundation.
How It Affects Fertility
- 1–2% annual testosterone fall from peak (compounding over decades)
- Progressive increase in sperm DNA fragmentation with age
- Reduced sperm motility and increasing morphological abnormalities
- Higher rate of de novo genetic mutations in sperm — risk to offspring health
Symptoms to Watch For
- Gradual barely-perceptible decline in energy and libido over years
- Reduced recovery speed from exercise and illness
- Subtle changes in body composition year on year
What You Can Do
- 1 Do not assume age-related decline is inevitable — optimisation at any age has significant impact
- 2 Sperm DNA fragmentation testing is strongly advisable for men over 40
- 3 Antioxidant protocol (CoQ10, vitamin C, vitamin E, selenium) reduces DNA fragmentation
- 4 Prioritise sleep, resistance training, and nutrition — these offset age-related decline significantly
This content is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before making health decisions.