Scientists from the University of Wisconsin studied the venom of the Brazilian Wandering Spider, the bite of which can cause tremors, excessive salivation and breathing difficulties.

The poison of the five-inch arachnid – also appropriately known as the banana spider – can additionally lead to priapism, an agonising condition which occurs when blood becomes trapped in the penis and causes abnormally long-lasting and throbbing erections.

Researchers investigated PnTx2-6 – the active ingredient in the spider’s venom – by cutting off the penis of a dead mouse (size isn’t important, after all) and connecting it to an electrical stimulator. They were then able to measure the contraction of the muscles when tissue came in contact with different chemicals.

They discovered that the venom not only worked as a stiffy stimulant, but that it has fewer side-effects compared with existing erectile dysfunction drugs such as Viagra.

“We have various toxins in this venom with different activity,” said physiologist Kenia Nunes, when the study took place in 2011. “Because of this, when a human is bitten by this spider we can observe many different symptoms including priapism, a condition in which the penis is continually erect.”

The researchers then developed a genetically modified culture of caterpillar cells to recreate the spider toxin. Wired reports that further trials to determine the toxicity of the drug in humans may take place, but a drug remains years away.

The need for caution is clear. The Daily Mirror reports that in 2013 a man had his penis amputated after overdosing on Viagra and having an unwelcome boner that lasted for several days. And an Indian man almost died when he suffered a three-week erection.

Reporter Gwen Pearson, for Wired, mischievously wonders when we can expect to see a cross-marketing campaign for SpiDurex condoms. We’re more concerned about the terrors of Erectnophobia…