Extenze is the second best male enhancement product that we tested. Although results were above average there are some serious concerns with Extenze that one must consider. Extenze has two ingredients in their formula that cause us concern. First is DHEA, which can cause a failed drug test. You may remember an infamous runner, LaShawn Merritt, who lost medals and got suspended from competition for two years because he took a male enhancement product that had DHEA. The second ingredient of concern is Yohimbe. Yohimbe has been known to cause high blood pressure and serious damage to the liver. We highly recommend that you should avoid Yohimbe until more is known about the safe and effective ranges of this herb, this is especially so if you have had a history of heart or liver problems. Extenze has a 2-month satisfaction guarantee. Customer satisfaction is above average.