Both of these claim to have yohimbine ' yohimbe ' in them , an herbal drug that has NOT been proven to promote erection . Pharmacologically , the mechanism of the drug would make it seem that it would cause the opposite , to be honest . It would cause constriction of your blood vessels something that actually prevents erection ! . This drug can actually amplify the effects of your methylphenidate and I would recommend staying away from the supplements . These supplements are NOT regulated by the FDA ! These companies can say they put these chemicals in their supplements , but really , there is no regulation as to what goes into these supplements . The claims these supplements make have also NOT been evaluated by the FDA . This is definitely not the type of treatment you should be seeking , in my opinion . If you can , I ' d recommend seeing your physician .