Tripping over Psychoactive Toads
Since kissing frogs has officially been discounted as a method of obtaining princes (sorry ladies), why would anyone want to lick a toad? The urban legend is that licking a toad can get you high. Indeed, Homer Simpson is seen licking toads and going on bizarre trips, as well as the infamous stories of hippies in the 70s who kept 'toad farms.' These stories are based on the fact that certain types of toad can produce psychoactive compounds in their skins and venoms, which can then be licked off. These toads are known as 'psychoactive toads', and they produce a chemical which causes hallucinations when ingested.
So, is licking a toad a good idea? Definitely not. Not only would it taste disgusting, it would be illegal and extremely bad for your health. The chemical which causes these trips is called 5-methoxy-N, N-dimethyltryptamine (5-MeO-DMT), and is a derivative of bufotenine. In its pure form it is extremely potent and causes vivid hallucinations. These vivid hallucinations are known as a 'psychedelic trips' and you're certainly not guaranteed to have a good one. Indeed, many users find them frightening and end up hurting themselves. One user described taking the drug as 'being shot out of a rifle barrel lined with baroque paintings and landing on a sea of electricity' (reference 1). Trips like this can be very, very dangerous, and can have serious long-term consequences on the user's mental health.
That's because, as well as these psychoactive bufotoxins, toad secretions and venom also contain other chemicals including substances that can target the heart and mimic hormones like adrenaline. This can lead to fatal disturbances in heart rhythm, such as ventricular fibrillation, as well as vasoconstriction and death (reference 2). There are also many reports of dogs dying after holding toads in their mouths and one case report of a child experiencing intense seizures after licking a toad (reference 3).
The venom is opaque-white in appearance and users collect it by 'milking' the toad with a squeezing motion, which causes it to ooze from skin surface. Taken orally, 5-MeO-DMT is actually inactive, and so licking a toad will expose you only to the highly dangerous cardiotoxic chemicals on its skin that are orally active. In fact, the only way to avoid the toxicity is to dry the venom and smoke it. And in an hilarious show of scientific bravado, two researchers actually used themselves as 'test subjects' and got high in the name of science (reference 1). Today they are both extremely well respected scientists in their respective fields. But before you try it yourself, even in the name of career progression, smoking the venom is now highly illegal (in Queensland, Australia, for example possession of toad slime is illegal under the Drug Misuse act).
More importantly, though, your chances of getting a good toad are slim. Because only a few toads actually produce these psychoactive compounds while the vast majority don't yet are nonetheless highly poisonous. Even a small amount of their venom can kill or permanently paralyse the licker. So which ones should the determined licker go for? Well the choice isn't large since just one species of toad, Bufo alvarins, is known to produce the correct chemical.
This toad is found in the Sonoran Desert in North America and catching one will be difficult because many amphibian species are disappearing fast due to climate change and loss of habitat. And before any Queenslanders go reaching for a cane toad as a alternative - cane toads don't actually contain any hallucinogens, but they are packed with lethal toxins instead (see reference 1, below).
The toads release the substances through their skins using specialised glands. 'Mucous' glands, as the name suggests, secrete mucus, whilst 'granular' glands secrete toxins. The role of these toxins is to protect the toad from predators like birds, mammals, snakes and crocodiles (see references 4,5 below) and they are thought to have developed when amphibians evolved from fish; so they're a consequence of having to deal with a new environment and new predators.
The secretions may also have other uses as antimicrobials (see reference 6), which may protect against diseases like red leg syndrome, mycobacteriosis and salmonellosis (reference 7). Some toads even make their own anti-virals like the BAS-AH protein isolated from Bufo andrewsi, which exhibits anti-HIV activity (reference 8). Currently, research is underway into the anti-fungal and anti-parasitic properties of some of these secretions too.
So, with all the amazing things these secretions can do, it is unsurprising to find that there is a lot of research in this area. These compounds have a huge potential to yield the medicines and cures of tomorrow. Each species is capable of producing different compounds, so there are literally thousands of new chemicals just waiting to be discovered. However, this incredible drug resource may soon be lost - toads are dying out at an alarming rate, and we may lose more than 50% of them in next 20 years due to loss of habitat, disease and climate change (see reference 9, below). This loss isn't helped by the fact some people catch and kill the poor beasts for their psychoactive substances.
In essence, toad-derived compounds have a fantastic ability to harm and heal, but should always be treated with caution. So the next time you spot a juicy-looking toad, remember all that you've read here- and 'just say no.'
1 Davis, W. The clouded leopard : travels to landscapes of spirit and desire. (Douglas & McIntyre ; Northam : Roundhouse [distributor], 1998).
2 Weil, A. T. & Davis, W. Bufo Alvarius - a Potent Hallucinogen of Animal Origin. J Ethnopharmacol 41, 1-8 (1994).
3 Hitt, M. & Ettinger, D. D. Toad Toxicity. New Engl J Med 314, 1517-1518 (1986).
4 Doody JS, Green B, Sims R, Rhind D (2006a) Initial impacts of invasive cane toads (Bufo marinus) on predatory lizards and crocodiles. In: Molloy KL, Henderson WR (eds) Science of cane toad invasion and control. Proceedings of the invasive animals CRC/CSIRO/Qld NRM&W cane toad workshop, Brisbane. Invasive Animals Cooperative Research Centre, Canberra, Australia, pp 33-4
5 Awasthi K 2006 Biocontrol Backfires; Down to Earth14 (22) 46-48.
6 Simmaco M, Mignogna G and Barra D 1998 Antimicrobial peptides from amphibian skin: what do they tell us? Biopolymers47 435-450.
7 Fox J G et al (eds) 1984 Laboratory Animal Medicine-ACLAM Series (New York: Academic Press). (s)
8 Zhao Y, Jin Y, Wang J H et al 2005 A novel heme-containing protein with anti-HIV-1 activity from skin secretions of (s)
9 A. D. Garg, R. Hippargi & A. N. Gandhare : Toad skin-secretions: Potent source of pharmacologically and therapeutically significant compounds . The Internet Journal of Pharmacology. 2008 Volume 5 Number 2