The Fast Size Extender, though not extensively tested, has received some validation from mainstream medical sources. But that makes it a true rarity among the nonprescription methods of male enhancement. Most are a waste of money, and some are downright dangerous, doctors say. Instead of furtively turning to untested methods, men with persistent concerns should consider opening up about them with their doctors. That's because performance problems sometimes act as an early warning signal for serious health problems. Your doctor might be able to prescribe something that can really help, or least provide a valuable dose of perspective about what constitutes "normal" sexual performance.