Asthenospermia means slow sperm motility...a risk factor for infertility. If this happened to you, you could try zinc sulphate 220 mg (50 mg elemental zinc) 2 tablets daily after food for 3 month which helped infertile men by increasing semen volume, progressive sperm motility, total normal sperm count, catalase-like activity in spermatozoa and seminal plasma, without any side effects.
I would also add other "energy producing" (and antioxidant) nutrients for the sperm including CoQ10 200 mg/d, magnesium 200-300 mg/d, carnitine 1000 mg (have your TMAO checked) and ribose 5 grams 3 x day for several months.
Be and Stay Well,
Kirk
You can call me for "brief" medical questions 8-9 a.m. PST Monday thru Friday
916-489-4400 KwikerMedical.com StayingHealthyToday.com