Urban legend has it that salt peter was once used to induce impotence in males, decreasing their sex drive and inhibiting erection. Salt peter, or potassium nitrate, is a naturally occurring mineral source of nitrogen, a chemical compound with the chemical formula KNO3.
The practice of adding saltpeter to foods to curb libido in male prisons, the armed forces and boys schools, is a myth that can not be confirmed. However, potassium nitrate is used medically to treat high blood pressure and relieve angina.
Although potassium nitrate is widely used as a fertilizer, its most important use was as an oxidizing component of gunpowder. It was used in the production of matches and slow burning fuses. It is still used today in fireworks, pyrotechnics and explosives.
Saltpeter is used in many products including ice cream, as a food preservative in the pickling of meat, toothpaste and fertilizers.
Potassium nitrate can be toxic in large quantities. It can cause headaches, anemia, dizziness and an upset stomach.
Saltpeter or potassium nitrate, can be purchased from Amazon.com in a one pound bag for $10.95 plus shipping.