Instead of reaching for the "little blue pill," men with erectile dysfunction could soon be turning to a "blue light" to solve their problems. Researchers have now developed a gene therapy that reacts to blue light, triggering reliable erections. While Viagra helps to prolong an erection, it does not actually trigger it, as this therapy claims to do.

Although an uncomfortable topic among men, erectile dysfunction begins to increase from the age of 30. In men over the age of 60, more than half of men have suffered this disorder in which normal sexual stimulation does not lead to an erection.

To solve this problem, scientists led by Martin Fussenegger, professor of Biotechnology at the Department of Biosystems in Basel, have developed a gene construct that reacts to blue light and is injected into the erectile tissue of the penis.

When it is exposed to light, a precursor molecule (guanosine triphosphate or GTP) is converted into the second messenger cyclic guanosine monophosphate (cGMP), which exists naturally in several human organs.

This allows voltage-dependent calcium channels to close, thereby reducing calcium levels in the cells, which in turn relaxes muscle cells and increases blood flow to the erectile tissue, causing the penis to become stiff.

An enzyme then breaks down cGMP so that the erection wears off with time, unlike Viagra, which blocks this enzyme in order to intensify and prolong the erection. Because of the gene construct, the production of cGMP is caused by exposure of the erectile tissue to blue light - not by sexual arousal.

The researchers tested this new development in male rats and found that in most cases, the blue light acted like a switch that allowed the rats' erection to be 'turned on.' Since the system of an erection is similar across all mammals, Fussenegger expects that the gene construct will also work in humans.

In terms of side effects, Fussenegger claims that the possibility is low, considering that injections in the erectile tissue are already a standard treatment for erectile dysfunction nowadays. Since the erectile tissue is mostly insensitive to pain and is detached from the normal blood circulation, he also claims that the risk of the gene construct reaching other parts of the body is very low.