After that she worked as a researcher at the Foundation Vrouw & Media from March 1983 until June 1986, where she studied the position of female journalists at Dutch newspaper publishers.

In 2003 Sax read the Mosse Lecture, titled Naar een nieuwe seksuele revolutie (Towards a new sexual revolution).

[2] Sax was active in Dolle Mina and was the co-founder of various feminist organisations: the Vrouwenhuis in Amsterdam in 1973, the abortion-rights advocacy group Wij Vrouwen Eisen in 1974, the department of Female Studies at the University of Amsterdam and the women's bar Saarein in 1978 where Dutch lesbian-feminist collective Lesbian Nation organised events (mother-daughter days, poetry nights, folk song days, themed parties, etc.).

Sax received a noteworthy heritage and in 1982 she gave Mama Cash an interest-free loan of 2,5 million guilders.

Sax has received different rewards for her efforts for the Dutch women's rights movement, like the 'Zilveren Anjer' of the Prins Bernhard Cultuurfonds in 1995 and the 'Bob Angelo Penning' of the COC in 1997.