Parents of year 8 students at Officer Secondary College were shocked to receive an email on Tuesday promoting abstinence as part of the school's Respectful Relationships curriculum, a state government initiative aimed at stamping out domestic violence.

"Our shared goal is to delay sexual activity in school-aged youth," it read.

One parent, who did not want to be named, said the school was sending students a "damaging, archaic" message by telling them to abstain from sexual activity until they graduated.

"It sets up a culture of shame around sexual desire and feeling, and a culture of secrecy when students are in relationships," they said.

"Students who are already engaged in sexual relationships may think having sex is inherently risky and dangerous."

Another parent said that while they didn't want their children having sex early, it was inappropriate for the school to promote abstinence. This created shame, and stopped children from getting help, they said.

"They expect that they wait until they're grown up and married. I don't think that's realistic."

The abstinence message may have been an effort to appease parents who have raised concerns about the controversial Safe Schools program, which they claim promotes inappropriate sexual activity.

Last year, the school experienced a backlash from some parents after it taught The Absolutely True Diary of a Part-time Indian. Parents objected to 13-year-olds reading the book's passages about masturbation.

The latest incident has raised concerns about how the Respectful Relationships curriculum – which is designed to challenge gender stereotypes and promote equality – is being interpreted by some Victorian schools.

While a focus on abstinence in sex education is common in some religious schools, it is unusual in secular state schools.

The school, which is located in Melbourne's outer south-eastern suburbs, told parents that the lessons would cover healthy and unhealthy relationships, pressures on young people, "how to live a healthy life and avoid risky behaviours (abstinence)", contraception and sexually transmitted infections.

"These lessons aim to provide students with medically accurate information and communication skills to help them make decisions that can keep them healthy and safe," the email read.

It said families held a range of beliefs, cultures and customs, and that it would ensure "all information is age appropriate". "Those family values are core, essential guidelines for your child's life," it said.

The email was only sent to parents of Year 8 students. The new school, which opened in 2015, only enrols students up to year 9 at this stage.

Assistant principal Elizabeth Godwin told Fairfax Media that the email sent to parents did not reflect the school's program.

"The Health and PE program at Officer SC aims to educate students in being respectful, responsible and informed," she said.

Focusing on abstinence ignores young people's sexuality, according to David Rhodes, a senior lecturer at Edith Cowan University who specialises in sex and sexuality in schools.

"We regard sexual identity as an adult thing, but it doesn't suddenly appear when you become an adult," Dr Rhodes said.

"[Abstinence] is such an old-fashioned and antiquated idea. To suggest that it's a shared goal puts undue pressure on parents and shuts down discussions about young people's sexuality."

Sex education consultant Jenny Walsh said programs that only pushed abstinence "let kids down".

"It does not arm children for if and when they have sex or speak to those kids who are already having sex," she said.

"Abstinence programs don't work when it comes to delaying sex or promoting sexual competence, which means having sex when you're ready and safe."

Ms Walsh said the school was ignoring data that showed that 25 per cent of year 10 students and half of year 12s have had sexual intercourse.

An Education Department spokesman said that the Respectful Relationships curriculum was separate to sexuality education.

"The goal of sexuality education in Victorian schools is to build on knowledge, skills, and behaviours, so young people can make responsible and safe choices."