| Medication | Effect |
| Exogenous testosterone | Decreased spermatogenesis |
| Androgen supplements | Impaired HPG axis |
| 5-α reductase inhibition | ED, impaired sperm production22 |
| α-blockers | Retrograde ejaculation |
| Cimetidine, spirinolactone, and ketoconazole | Direct inhibition of androgen production |
| Erythromycin, neomycin, tetracycline, nitrofurantoin, and gentamycin | Direct impairment of sperm production |
| Selective serotonin receptor inhibitors, monoamine oxidase inhibitors, lithium, and phenothiazines | Decreased libido, ED, and alteration of the HPG axis23 |
| Chemotherapeutic agents | Direct impairment of spermatogensis |
| Marijuana,24 cocaine,25 alcohol,26 and tobacco27 | May impair the HPG axis, spermatogenesis, and erectile function |
ED, erectile dysfunction; HPG, hypothalamic-pituitary-gonadal.