Kenyan-born and Tanzania-based sexual health educator Maureen Oduor knows that soda doesn’t prevent pregnancy, but not all of the young women she counsels do. "In Kenya, adolescents believe that drinking a glass of Coca-Cola soda before and after sex can prevent a girl from getting pregnant," she tells me. In Tanzania, meanwhile, "people believe that use of contraceptives by a woman who has never had a child causes a woman to be barren or give birth to an abnormal child" — and in both countries, "there is a belief that if a girl [does] not have sex as a very early teen, like 12 or 13 years, then the vaginal opening is likely to close or get sealed."In her work in Tanzania for SHDEPHA, an organisation that fights discrimination against people with HIV/AIDS and replaces contraception misinformation with education and services, Oduor is a professional myth-buster. Her passion for sex ed is personal. When she was 13, she tells me, she and her classmates at the all-girls boarding school they attended in rural Kenya arrived at their dorm after church one Sunday to find one of their fellow students — also 13 years old — lying limp on her bed. "The whole bed was soaked with blood, and the blood was dripping down," Oduor says. "We didn’t know what to do, because we had never seen something like this. Sundays in Kenya, most facilities close; our own school facility was closed. This was a school right in the village, eight kilometres to the tarmac road."The girls’ classmate was bleeding to death before their eyes. "We [were] around eight students — we tried carrying her, but she was so tired; she had lost a lot of blood, so we just tried supporting her, and we walked for those eight kilometres," Oduor continues. "When we reached the tarmac road, that is around two, two and a half, three hours of walking, we got a vehicle. On reaching the hospital, she had already died." Oduor learned from hospital staff that her classmate had died from complications of an unsafe abortion, but quickly discovered that none of the staff at her school would admit as much to the students."What angered me most and what made me ask myself many questions was that this story was supposed to be swept under the carpet," Oduor says with intensity. "They [said] the girl was just sick, she died, okay, she’s going to be buried… She was not taught about family planning, she was not taught on how to negotiate [sex]... I witnessed that, and that’s how my world turned around, and I said, 'Is there anything I can do?'"Oduor and I are speaking at the 2016 International Conference on Family Planning in Indonesia, and Oduor, now 30, has done quite a lot since witnessing her classmate’s death, starting a peer counselling group at her boarding school and going on to lead youth outreach at grassroots organisations in Kenya and Tanzania. Her message is clear: Young people are having sex, and they have the right to do it safely. "Young people are ready for this, and the time is now — we cannot say it is tomorrow," she says.The world is welcoming the largest generation in history to its reproductive years. There are now 1.8 billion people between the ages of 10 and 24 — that’s the group the WHO defines as "young people" — and, shocking no one, they're having sex with each other. According to the Guttmacher Institute report Adding It Up: Costs and Benefits of Meeting The Contraceptive Needs of Adolescents , presented last month at the Women Deliver conference in Copenhagen, some two-thirds of adolescents in Africa and Latin America report having sexual intercourse by the age of 19; in Asia, the figure is around 41%, and that’s among both married and unmarried teens. Of the 252 million 15- to 19-year-old women in the developing world, 38 million are having sex and don’t want to get pregnant, but 23 million of those 38 million aren’t using modern contraception, a rate of unmet need that’s much higher than among adult women. Lancet study presented alongside the Guttmacher Institute report at Women Deliver reveals that unsafe sex is now the fastest-growing risk factor for ill health in young people (that’s all of them, not just those in developing countries), jumping from the 13th leading cause of death for 15- to 19-year-olds in 1990 to the second leading cause of death for them in 2013. In part, that's because the global health community has assumed teens to be healthy, with little need for specialised attention or investment. (That assumption hinges on not actually talking with teens about the fact that around the world, they are increasingly facing not only unsafe sex but injury, violence, obesity, and mental health issues.) And yet we know that denying young people contraception information and services leads to life-altering — or life-ending — consequences, including unintended pregnancy, STIs, pregnancy complications, social alienation, incomplete education, unemployment, poverty, and unsafe abortion.