sentences:  There is also evidence to suggest some preparations may be toxic if taken in larger doses.Additional side effects and dangers of common herbal viagra adulterants, such as sulfoaildenafil, acetildenafil and other analogs, are unknown because these ingredients have not had thorough review in human clinical trials.Herbal viagra is predominantly sold through the internet, and in 2003 approximately 4% or 1 in 25 of all email spam offered herbal viagra, genuine pharmaceuticals, and other herbal remedies.