In the 1980s Östergren helped launch a feminist self-defense movement in Sweden. She was active as an instructor in the organisation Pandora kvinnligt försvar and ran the Kung Fu club in the kajukenbostyle in an effort to help women defend themselves against sexual assault. She was involved with the National Organisation for Women's Shelters and Roks. She is the author of Slå tillbaka!: Handbok i självförsvar published in 1993. She also wrote a book about her mother, who was beaten to death by a man she had had a brief relationship with, entitled Att komma till ro med det allra värsta.
Her involvement with teaching men self-defence made her a controversial figure with radical feminists, and the rift became complete when she published an article in Bang magazine in which she questioned whether all pornography was essentially misogynous. Östergren is considered a major critic of radical feminism in Sweden. In particular she has challenged their views on sex, violence and power, pointing out that violence in lesbian relationships did not differ significantly from that in heterosexual relationships. From its origin, Östergren was one of the few people who publicly challenged the radical feminist position on prostitution which culminated in the sexköpslagen 1999. She has been an advocate for the decriminalisation of prostitution. In 2006, she published Porr, horor och feminister, an analysis of three decades of Swedish policy on pornography and prostitution, and a critique of radical feminist sexual politics. In 2008, she published an edited volumeF-ordet: Mot en ny feminism, bringing together writers and commentators to provide new perspectives on old feminist issues.
Work
In addition to her books, Östergren writes regularly for newspapers and magazines, including Svenska Dagbladet, LO-tidningen, Expressen, Aftonbladet, Axess and Voltaire and regularly gives public talks, and is consulted on prostitution and gender issues.
Books
Slå tillbaka!: handbok i självförsvar för kvinnorNatur och Kultur, 1993. Revised 1998
Att komma till ro med det allra värsta], Natur och Kultur, 1996
Porr, horor och feminister, Natur och Kultur, 2006