Mossman–Pacey paradox

The Mossman–Pacey paradox is an evolutionary irony{{Broken anchor|date=2024-07-25|bot=User:Cewbot/log/20201008/configuration|target_link=Irony#Situational irony|reason= The anchor (Situational irony) has been deleted.}} in which certain actions often taken by men to improve their sexual attractiveness end up lowering their fertility.{{Cite news|url=https://www.bbc.com/news/health-48396071|title=Male beauty quest 'damages fertility'|last=Gallagher|first=James|date=2019-05-28|access-date=2019-06-08|language=en-GB}}{{Cite web|url=https://www.newsweek.com/mossman-pacey-paradox-men-trying-look-pinnacles-evolution-risk-becoming-1436988|title=Mossman-Pacey paradox: Men trying to look like the "pinnacles of evolution" risk becoming sterile, scientist warns|last1=G|first1=Kashmira|last2=EDT|first2=er On 5/28/19 at 8:18 AM|date=2019-05-28|website=Newsweek|language=en|access-date=2019-06-08}}{{Cite journal|last1=Andersen|first1=J. T.|last2=Dalhoff|first2=K. P.|last3=Horwitz|first3=H.|date=2019-04-08|title=The Mossman–Pacey Paradox|journal=Journal of Internal Medicine|volume=286|issue=2|pages=233–234|language=en|doi=10.1111/joim.12885|pmid=30957922|s2cid=102347361 |issn=1365-2796|doi-access=free}}

One of the most prevalent manifestations of this phenomenon is the use of anabolic steroids by some men (particularly if they go to the gym). These steroids can help build larger muscles, but can also lead to side effects such as smaller testicles, erectile dysfunction, and lower sperm count. One of the main reasons for this is that anabolic steroids can stop the pituitary gland producing the hormones LH and FSH. It has been estimated that approximately 90% of anabolic steroid users are at risk of infertility.{{Cite web|url=https://www.menshealth.com/health/a27609848/mossmanpacey-paradox-quest-fertility/|title=Doctors Warn Using Steroids May Cause Irreversible Infertility|last=Matthews|first=Melissa|date=2019-05-28|website=Men's Health|language=en-US|access-date=2019-06-08}}