Discussions on sex, abortion and eating disorders are to feature in a new education programme for Girl Guides.
Discussions happen in a female-only environment
Guides will be trained as "peer educators" to teach others aged between 10 and 25 about such things as sexual health and binge drinking.
Girlguiding UK said the move follows complaints from Guides, most of whom are between 10 and 14, that such issues are often poorly handled in schools.
It hopes they will learn from each other in the female-only environment.
The overall peer education programme is now into its third year.
Previously it has tackled subjects including disabilities awareness and world poverty, but this year it will tackle more sensitive issues that girls may face as they grow up.
Among the possible topics are contraception, anorexia and date rape.
The movement mainly includes girls aged between 10 and 14, but a senior movement allows some to continue until they are 25.
More than 450 Guides, aged over 14, are to receive training before visiting guide groups, schools and youth clubs where they will hold discussions and work on role-plays about the subjects.
Vicky Willis, 22, has been a Guide since the age of five and now chairs the peer education programme.
She said: "We offer a very safe environment to discuss those issues. They can talk more openly because it's only girls."
TOPICS FOR DISCUSSION
Denise King, chief executive of Girlguiding UK, said: "We see it as our responsibility to give girls and young women the knowledge, experience and confidence to understand and manage the issues that face them today."
The organisation, now in its 97th year, has suffered from an image problem in the past.
One of its biggest problems now is finding enough volunteer leaders - there is a waiting list of about 50,000 girls wanting to join.
Miss Willis said: "I think gradually people are changing their views of the association.
"There are still a lot of stereotypes but we are in fact very modern and it is always adapting its programme."