Amazon has the 60-Count Force Factor Zinc Magnesium Aspartate Supplement for $11 - 5% off with Subscribe & Save (can cancel anytime) = $10 with free shipping on $25+ or with Prime (extra 15% off with 5 items S&S order). Contains zinc, magnesium, and Vitamin B6, the combination of which has been clinically shown to support testosterone production, strength, and power.