Social media fertility myths spread alongside uncertain science on sperm decline

A UN report shows global fertility rates falling, while influencers promote unproven methods to boost sperm count amid conflicting scientific evidence.

• The UN reported in 2025 that the global fertility rate fell from 4.9 children per woman in 1950 to 2.2 per woman in 2025, with 106 countries below replacement level.
• US Health Secretary Robert F. Kennedy Jr. stated that men in 1970 had twice the sperm count of today's teenagers, calling it a "fertility crisis."
• A comprehensive 2023 review concluded that the causes and impact of sperm decline remain unclear, while 2024 and 2025 studies in the US and Denmark found no recent decrease.
• Influencer Lucas told his YouTube audience that men will become infertile within 33 years, a claim unsupported by evidence, and sells unapproved supplements and training programs.