That's according to the Center for Disease Control's Youth Risk Behavior Survey, which found the percentage of high schoolers in the USA who have had sex plummeted, from 47.8 percent in 2007 to 39.5 percent in 2017.
Many are at risk of contracting HIV and other sexually transmitted diseases, as well as become victims of violence.
"At the same time, the rate of violence and victimization they're experiencing hasn't gone down".
Researchers asked about 100 questions to more than 3.8 million high school students in more than 1,700 separate surveys on a wide range of health topics, including smoking, drugs and diet. A limitation of the data is that they are self-reported by the students, and they include only those in schools, not those who may be homeschooled.
In the latest report, the CDC compared the data collected between the years 1991 and 2017 which showed that there is a 20% decrease in the number of high school students who had alcohol, a 15% decrease in the students who had sex and a 6% decrease in students that use hallucinogenic drugs. "They're having fewer partners. They're more likely to use effective methods of hormonal birth control".
One-third of teens in the survey said they were obese or overweight, an increase from previous years.
Findings of a new government survey have revealed a seemingly tamer generation of teens.
The rates of attempt are highest among students in the LGBTQ community.
Among students who were now sexually active, 29 percent said either they or their partner used some type of long-acting, reversible birth control, such as an IUD, implant or birth control pills.
In 2017, 9.7 percent of students had four or more sexual partners, down from 14.9 percent a decade ago. The use of condoms among teens fell in 2017 to 53.8 percent, compared to the 62.8 percent in 2005.
Fourteen percent reported use of prescription pain medication without prescription or in a different way than prescribed. However, about 1 in 7 said they'd taken opioids without prescription.
"Additionally, we need more focused curriculum to engage with students in a dialogue about decision-making, dispelling myths, and the science of opioids and the risks/benefits of use", Kapoor said. "All those are really positive directions". That compares to almost 15 percent in 2007.
Since the year 1991, there has been an increase in the number of students who feel "sad" or even "hopeless" and since the year 2007, there has been a resurgence of suicide thoughts. That finding is "very concerning", Ethier said.
An estimated one in 10 female students and one in 28 male students reported having been physically coerced to have sex, according to the report.
Nationwide, 17.2 percent of students had seriously considered attempting suicide during the 12 months prior to the survey. "That's a very disturbing trends to see", said Dr. Bela Sood, a child and adolescent psychiatrist and senior professor for child and mental health policy at the Virginia Treatment Center for Children at Virginia Commonwealth University in Richmond. Other CDC data show completed teen suicides have been rising in recent years, along with a rise in adult suicides. "I think that's the implication of these statistics, that they tell you where to put your efforts".
"The health of our youth reflects the nation's well-being", CDC Director Dr. Robert Redfield said in an agency news release.
Overall, teens are practicing a number of more conservative behaviors.