Gerisan is a natural product from the rhizomes of blood geranium (Geranium sanguineum).

Aside from individual successes in the use of vaccines, humanity still lacks a sufficiently reliable and universal means to combat viral infections.

Many Bulgarian scientists have studied medicinal plants from our area in terms of their antiviral action. The virological studies carried out were initially of a screening nature. The development of molecular biology and virology has opened new horizons in the knowledge of viral reproduction and, of course, the pathways to influence it.

The prerequisites for success in the development of antiviral preparations of plant origin in Bulgaria are many. First and foremost is the extraordinary wealth of medicinal plants that can be found in our nature. Important is also the centuries-old experience in their use in our folk medicine, which has produced great healers (Ivan Rilski, Ivan Raev, Dimitar Dimkov, Dimitar Krastev).

The presence of world-class scientists in phytotherapy (Veselin Petkov, St. Ivancheva) and virology (Manolova, Maksimova, Sabeva, Lasev, Dundarov, Andonov, Serkedzhieva) is an undeniable fact.

The medicinal plant Geranium sanguineum L (blood geranium) has been studied in detail and in depth by many Bulgarian authors. A pronounced inhibitory effect against the multiplication of some strains of influenza virus by the polyphenol complex isolated from it has been found.

The polyphenol complex acts on the biological activity of the virus, which is detected by hemagglutination titer, and competes with the virus for cell membrane glycoproteins, inhibiting some phases of viral infection. Because of its small molecular mass, the polyphenol complex penetrates the cell membrane of the already infected cell, inhibiting the intracellular stage of virus replication.

There are experimental results that give grounds to assume that the polyphenol complex obtained by extraction of Geranium sanguineum L, in certain concentrations, completely inactivates the infectious activity of influenza viruses.

In Bulgaria a preparation from the roots of blood geranium (this part of the plant is the richest in polyphenol complex) called "Gerisan" was created and is produced. It has been on the market since 2001 and for the elapsed time sufficient experience has been accumulated through its application in helping the prevention and treatment of viral infections in general.

Gerisan, administered in doses of 1 capsule daily, significantly reduces the likelihood of infection with the influenza virus during epidemics.

All these studies and data give us reason to assume with a high degree of confidence that "Gerisan" can be used to help prevent particularly dangerous and deadly viral infections such as avian influenza, swine flu and others.

Scientists believe that combined with the synthetic drug remantadine, Gerisan is potentiated to create even greater protection against viral infections.

Gerisan reflects the possibilities and richness of our nature, as well as the power of native science.