Comparing Zytenz vs. Virectin, complaints. The Mayo Clinic claims supplements like Zytenz and Virectin can be dangerous for your Blood Pressure during sex. This is because with both Zytenz and Virectin, you swallow Ginseng. 61% of Virectin Customer Reviews at Amazon are unsatisfied 3 stars or lower. Meanwhile, Many Zytenz Reviews claim Zytenz is just an average working pill with a common formula seen in many pills. Zytenz is the lesser of two evils.