Safe Haven is launching Text Sam across Britain to provide information for young men and women about contraception, sexually transmitted diseases, pregnancy and sexuality.
It was piloted in the London boroughs of Southwark and Lambeth, where almost 90% of young people have had a sexually transmitted disease, according to the charity. The text service received more than 42,000 requests for information in just two months during its pilot.
The innovative service was developed after a survey found 96% of 14- to 16-year-olds depended on their friends for advice. Text Sam hopes to reduce the number of unplanned pregnancies and sexually transmitted infections by letting young people make informed decisions.
Jacqui Jennings, the scheme's operations manager, said: "We have a national crisis on our hands which is getting more out of control every day. We as a society have an obligation to inform our young people of the possible consequences of having sex. We cannot expect young people to make sensible decisions without knowledge."
The charity said new diagnoses of syphilis, thrush, chlamydia and human papilloma viruses - some of which can cause genital warts and cervical cancer - had also risen in the two boroughs.
Nationally, nearly 1million people were tested for sexually transmitted diseases during 2006. Diagnoses of new sexually transmitted diseases in the UK rose by 2% to 376,508 in 2006 and new cases of genital herpes were up 9% to 21,698, according to the Health Protection Agency.
The UK has the highest teenage birth rates in western Europe - twice the level found in Germany, three times higher than France, and six times above figures in the Netherlands, according to a Unicef report.
· To obtain free sexual health information, text Sam to 60030. A text message will be sent which contains links to the nearest sexual health clinic and advice centres plus information about infections.