Not really. According to a paper published N.I.H. here:
A Validated Age-Related Normative Model for Male Total Testosterone Shows Increasing Variance but No Decline after Age 40 Years
Total T stays fairly constant after the age of 40 in spite of what most doctors tend to believe. The left side of the curve (men with total T < 50 percentile) tends to skew further left, while the right side of the curve stays constant for ages 40-88 - which suggests environmental factors are the cause of any observed decline in
average total T across the population instead of age. I know Rip has beat this drum before. But it's refreshing to see it published.