The underlying anatomy and general principles of enlargement don't fundamentally change by age, but a few things commonly do:
If erectile function, not size, is your primary concern regardless of age, that's covered in depth by our sister site, the Erectile Dysfunction Clinic. A consultation here can help clarify which concern is actually the bigger priority.
Does penis size change with age?
Significant, non-medical size change isn't typical in normal aging. Any noticeable change is worth discussing with a healthcare provider.
Is it too late to pursue enlargement later in life?
No specific age rules out non-surgical methods, though general health becomes more relevant to discuss as you get older.
Should younger men wait before considering enlargement?
No strict minimum, but it's worth exploring whether the driver is comparison and confidence first - see Small Penis Anxiety & Body Image.
Whatever your age, the starting point is the same: an honest conversation.