Government Warning

• The U.S. Federal Drug Administration (FDA) has issued numerous press releases alerting the public to potentially harmful ingredients found in these products. In 2009, the FDA issued a press release stating that some of the natural male enhancers investigated are contaminated with unproven, illegal drugs that pose an "unpredictable risk and the potential for injury or even death."
  
  

Cardiovascular Effects

• In particular, the FDA points to the inclusion of sulfoaildenafil in certain natural male enhancers, a precursor to sildenafil, the active compound in the prescription drug Viagra. Sulfoaildenafil may intensify the effects of blood pressure medications containing nitrates, leading to a sudden and dangerous drop in blood pressure.
  
  

Immune Function

• Many natural male enhancers contain pine bark extract, which may interfere with chemotherapy drugs and immunosuppressants.
  
  

Heart Rhythm

• Another common ingredient, epimedium (known as horny goat weed), is known to trigger rapid, irregular heart.
  
  

Other Considerations

• While some ingredients in natural male enhancers may increase declining testosterone levels, lack of regulation increases the risk of poorly standardized or contaminated ingredients.