Dr. Harry Fisch is a board certified urologist at New York Presbyterian Hospital/Weill Medical College of Cornell University. Each week, he’ll answer reader questions in an effort to get guys to ‘man up about health.’

I'll be honest, I'm lacking in the penis department. I've seen a ton of ads for penis extenders but do they really work? -- Devon, 22

Simply put -- No. You cannot increase the length or girth of your penis beyond what your genes and Mother Nature have endowed you with.

Various vacuum devices can produce an artificial erection, but that’s all—they will not “stretch” the tissue except in a harmful way.  These devices are hazardous if used excessively—by trapping blood in the penis for long period of time you risk tissue death and gangrene.

There is a surgical procedure that can increase the apparent length of the penis. Snipping the “suspensory ligament” lets the flaccid penis hang lower, providing an illusion of greater length.  But no growth has actually occurred and now your penis will be very “floppy” when it’s erect.

My advice: make the most of what nature gave you.  Remember, it’s not the size of the instrument, it’s how you play the tune.