One example is KSM-66 ashwagandha, a well-known extract that has been evaluated in multiple clinical trials, including randomized, double-blind, placebo-controlled studies
The digested peptide was eluted, vacuum dried, and fractionated using high pH STAGE (Stop-and-go extraction) method into two pools, then subjected to nano-HPLCMS/MS analysis
Hard to prove, but impossible to ignore
Diabetes Mellitus Factsheet
Under GB regulation, selenium carries an authorised health claim that it "contributes to normal spermatogenesis." If you're trying to conceive, selenium is one of the nutrients you'll see named on most male fertility supplements, usually somewhere near zinc