You could take Vitamin A from Cod Liver Oil. I found this local site:-
Vitamin A ?(HEALTH & FITNESS PRACTICALITIES)?
And also L-Arginine. Stay away from sugars, starch, beans and milk. Both beans and milk have high levels of estrogen, making us more female over time.
Dr. Wright's Tahoma Clinic
Most importantly, get some exercise. Can u remember when you sprinted or carry explosive exercises (no punt intended)?
I am 40 but libido still very good. Can do 2nd time in 30 minutes and still need 1 to 2 times per day.