Irish teenagers who took part in a new sex education programme said they were better informed and more aware of the consequences of their actions afterwards.
A new study by UNESCO Child and Family Research Centre at NUI Galway into the REAL U programme also found that young people's attitudes to LGBT issues and knowledge about the facts of sex improved significantly.
Funded by the HSE Crisis Pregnancy Programme, REAL U is designed to delay the onset of early sexual activity.
Dr Susan Redmond from Foroige said the format is what makes the course work.
"Because it's in smaller, group work settings it enables people to have richer conversations than maybe they would be able to in a larger group," she said.
"It focuses largely on developing skills, so there's a lot of interactive simulations of particular roles and looking at different issues such as how we as a society look at sex education and the development of relationships."