I have a vague memory of writing a story back in the 1990s about researchers trying to figure out how to use lethal cone snail venom for medical purposes. Well, EurekAlert says they finally succeeded:
[Chemical & Engineering News] Senior Editor Bethany Halford notes that a sea snails’ saliva contains chemicals that help the slow-moving creatures catch prey.
…
Now scientists in Australia have developed a form of the painkiller that can be given by mouth. It relieves severe pain, such as that in people with peripheral neuropathy, at a much lower dose than existing medications and without the risk of causing addiction. The article quotes one expert as speculating that such a drug could revolutionize the treatment of the most severe forms of pain.
More at C&EN. (Best part: how chemists figured out the way to get the toxin to work by studying Congolese herbal remedies.)