What happens if i guy takes more than one 30mg oxycodone a day, can this make him infertile?

Perhaps: It has been well demonstrated that chronic use of high doses of opioids decrease testosterone levels and sperm counts. There are differences among individuals as to what dose and how long before this becomes clinically significant and the best way to determine this is to have your primary care provider obtain free and total testosterone levels to evaluate this and consider sperm analysis.