A FEW days after the premiere issue of Sassy magazine appeared on newsstands last month, editor Jane Pratt received a letter from a 13-year-old reader. ``The day she got the magazine, her boyfriend was pressuring her to have sex for the first time,'' Ms. Pratt explains. But because the girl had just read the cover story entitled ``So you think you're ready for sex? Read this first,'' she said ``no'' to him. ``She told us she didn't think she would have had the courage to say `no' otherwise.''
Pratt hopes letters like this signal a promising future for the controversial new magazine, aimed at 14- to 19-year-old girls. Patterned after a brash, highly successful Australian magazine called Dolly, Sassy intends to shake up the teen magazine market by treating in a forthright manner such sensitive subjects as sex, suicide, and AIDS.
``We don't leave anything out,'' Pratt says. ``We don't use euphemisms, and we don't apologize. Basically there's nothing of interest to teens I wouldn't publish.''
Some parents and educators may disagree with that philosophy, arguing that the candor in the cover story on ``Losing your virginity'' is offensive. Pratt defends the approach, saying, ``Readers are getting a lot of explicit information from us. But underlying that there's a very responsible tone. We're saying, `You don't have to rush out and do this.'''
Another article in the premiere issue deals with teen suicide from the perspective of friends and relatives of three teen-age victims. Pratt hopes the approach will ``deglamorize and deromanticize'' suicide. Next month she plans to run an article about a 19-year-old boy with AIDS.
Pratt, a poised, articulate brunette, came to Sassy after a stint as an associate editor at the now-defunct Teen Age magazine. At 25, she claims to be the youngest editor of a national magazine.
She describes her own adolescence as ``semi-smooth,'' adding, ``I don't think any teen-ager has a totally smooth adolescence.'' Her parents were divorced when she was 13. At 14, she went away to boarding school. ``I did a lot of things that seemed like major traumas at the time,'' she recalls.
The memory of those not-so-distant ``traumas'' makes her sympathetic to the challenges teen-agers face. ``They carry a lot of responsibility. They do the family grocery shopping - things that weren't true 10 years ago. The way families have shuffled around, they're carrying a lot of burdens.''
Many are from broken homes. ``There's also pressure to go to good schools, get good grades, and do as well as their parents have - even though that's very hard economically today.''
Girls also tell her about peer pressure to try drugs and sex. ``It's not just pressure from boyfriends to have sex, but from other girls, who say, `I've done it.'''
As Pratt talks to teens at shopping malls and rock concerts, she hears other youthful fears. ``They're concerned about friends talking behind their back. They're concerned about getting along with their stepfather. They're concerned about AIDS. So they have the same old problems teen-agers have always had, as well as new problems and pressures. They see them all as equally important.''
To counter the ``heavy stuff'' in girls' lives, Pratt includes features on fashion, music, films, and beauty. A makeover column in the first issue reflects her own views that teen-agers in general wear too much makeup. ``I'd like them to wear less,'' she says.
She also takes a strong stance against diets, calorie counts, and spot toning. ``All the teen-age magazines do articles on it. They may not realize the huge impact that has in terms of all the eating disorders teen-agers have. If I can have anything to do with stopping that, I want to.''
In addition to its frank treatment of subjects like sex and death, Sassy has shocked some parents and competitors by becoming the first teen publication to accept condom ads. ``It was done very intentionally,'' Pratt insists. ``The United States has twice as much teen-age pregnancy as countries where there is mandatory sex education in schools.''
At the same time, she notes, the magazine has turned down ``salacious'' advertising. She cites fragrance and fashion ads that ``promote sexuality in a very general way,'' such as Calvin Klein's ``Obsession'' and Donna Rice's ``No Excuses'' jeans.
Sassy is published by Fairfax Publications Ltd., which owns Ms. magazine. Pratt expects the initial circulation of 250,000 to grow to 1 million in five years.
Ira Garey, publisher of Seventeen, the leading teen magazine, says he plans no changes in editorial approach or advertising policies in response to Sassy. Citing the 1,800,000 circulation of his 44-year-old magazine, he says, ``We have had record-breaking circulation in 54 of the last 60 issues. As they say, `If it's not broke, don't fix it.'''
Then he adds philosophically, ``We'll let the reader decide whether they like the magazine or not.''