The Weakness of the Werewolf

Werewolves were typically feared in folklore and myth. Benevolent werewolves only begin to appear in modern day fiction, and even there they are a minority. It should come to no surprise that people would comfort themselves with their knowledge of what kills or otherwise harms these monsters.

Silver

A thousand ounce bullion bar of this precious metal  (Source)

Everyone knows the foolproof method of slaying a werewolf. The silver bullet. Guaranteed to pierce through the werewolf's durability and regenerative abilities.

Or is it?

Not as effective as claimed? (Picture source unknown)

Stories of werewolves being weakened by silver don't actually show up until the 19th century, much later than the myths of werewolves themselves.

If that isn't enough to make you scratch your head, take a look at silver's alchemical symbol, in use since ancient times:

Look familiar? It's a symbol also often associated with werewolves...