The University of Edinburgh study tested the effect of paracetamol
on testosterone production in mice that carried grafts of human testicular tissue.
Romanelli F, Valenca M, Conte D, Isidori A, Negro - Vilar A.» Arachidonic acid and its metabolites effects
on testosterone production by rat Leydig cells,» J Endocrinol Invest.
However, this study focus on individuals with zinc deficiencies and didn't offer any evidence of the effect of increased zinc
consumption on testosterone production in men who already eat a zinc - rich diet.
To find out if this effect
on testosterone production might affect mice's fertility, the team knocked out the gene for osteocalcin in a group of the rodents.
It is believed that this was caused by the increases in exercise capacity stimulated by creatine instead of any impact creatine might have had
on testosterone production.
Although the effect that marijuana has
on the testosterone production has been subject to many studies their results are inconclusive at best.
Just getting older can have significant impacts
on Testosterone production (just as in men).
I does appear to actually improve libido and fertility but research clearly shows that it has no effect
on testosterone production, body composition, or exercise performance.