Venom from the Brazilian Wandering Spider has been known to give men a long-lasting and painful erection.

Earlier this year, scientists began harvest PnTx2-6, the active ingredient in the spider's venom, to create a natural Viagra that can work in 20 minutes.

While this compound has been shown to work on mice, it also has the side effect of congesting major organs, such as the heart.

Now, new research has identified another chemical in the venom that is less dangerous - and scientists say it could give men erections for hours at a time.

Tremors, excessive salivation and difficulty breathing are all signs you may have been bitten by a Brazilian Wandering Spider (pictured). In a number of cases, the venom of these arachnids can cause another unexpected symptom; intensely painful erections that last for hours at a time

Brazilian Wandering Spiders can cause priapism - a condition which occurs when blood becomes trapped in the penis, leading to abnormally long-lasting erections.

The venom contains something called PnPP-19, which scientists say has all the benefits of venom, without any of the damaging side effects.

When tested on mice, they found that it induced erections, but without damaging their organs.

In a research paper, scientists from the Federal University of Minas wrote: 'These findings make it a promising candidate as a novel drug in the therapy of erectile dysfunction.'

Although drugs such as Viagra, Cialis and Levitra have revolutionised treatment in the last ten years, around 30 per cent of men who take them see no improvement. A drug made from spider venom could prove to be an effective alternative

Back in 2011, when the research took place, Dr Kenia Nunes, a physiologist at the college, said: 'The venom of the Phoneutria nigriventer spider is a very rich mixture of several molecules.

'These molecules are called toxins, and then we have various toxins in this venom with different activity.

'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.'

Separate tests carried out on rats show the venom boosts performance by increasing the release of nitric oxide, a chemical that dilates blood vessels and improves blood flow.

FORGET VIAGRA, JUST EAT GREEK Never mind those little blue pills – men who have problems between the sheets could reinvigorate themselves simply by eating a Mediterranean diet. Eating fish, salads and olive oil, and enjoying the odd glass of wine, could transform the lives of men suffering from impotence, according to Greek cardiologist Athanasios Angelis. He said his research had shown that consuming such healthy foods helped clean out blood vessels, especially the narrow ones in the penis that are essential for a man to perform. Dr Angelis, an expert on erectile dysfunction at Hippokration Hospital in Athens, said: 'The Mediterranean diet is well known to be a healthy diet, one that is associated with longevity, wellbeing, lower incidence of cancer and cardiovascular disease. 'And this is very important, because people can choose this type of diet to prevent or restore their vascular health.' He explained that when a man had problems achieving an erection, 'it can be a sign of worse health problems to come', because the blood vessels in the penis were 'very, very sensitive' to what was happening in the rest of the body. 'Adopting a healthy diet and lifestyle can help reverse moderate erectile dysfunction,' Dr Angelis said. Advertisement

Now that scientists can create more of the venom, trials to determine the toxicity of the drug in humans may take place – although a product is likely to be years away.

Although drugs such as Viagra, Cialis and Levitra have revolutionised treatment in the last ten years, around 30 per cent of men who take them see no improvement.

For these men, the only other options are to inject drugs straight into the penis, or use a pump that manually increases blood supply to the organ. Neither is very popular.

A drug made from spider venom could prove to be an effective alternative.