Frog skin is covered with a cocktail of protective toxins. Some discourage predators; others prevent the growth of bacteria and fungi on the moist skin. Some of these chemicals are nearly identical to those that regulate our muscles and nerves. And it's no coincidence. The frog's toxic arsenal evolved, in part, as a defense against mammals that eat them. Because we share common ancestry with other mammals, many frog toxins are remarkably potent in the human body. Some are being studied for use in human medicine.

© Taran Grant/AMNH

Phantasmal poison frog, Epibpedobates tricolor

Frog toxins may be used to treat:

• Heart ailments
• Bacterial and viral infections
• Skin and colon cancers
• Depression
• Stroke
• Alzheimer's disease
• Chronic pain

The phantasmal poison frog from Ecuador and Peru secretes an analgesic called epibatidine. This powerful painkiller is 200 times more potent than morphine and is non-addictive. Chemists are working to perfect a less toxic version of the drug for use in human medicine.