And the message still resonates with women.
"We speak in a really authentic voice to women," Kate White, the magazine's editor-in-chief, tells The Early Show co-anchor Hannah Storm. "We don't try to be their sister or the authority. We're like that smart, fun, girlfriend who is going to tell you like it is. I think women really crave empowerment, someone that says to them: 'Yeah, go for it, baby.'"
Lois Banner, professor of history and gender studies at University of Southern California, says, "It created a revolution in mainstream magazines. It did give women permission to talk about sex."
Banner, who has studied the evolution of Cosmopolitan, says the magazine was launched back in the 1880s as a general interest publication. But in 1965, innovative editor Helen Gurley Brown marched in, daring to tackle taboo topics.
Banner explains, "She did talk about birth control. She did talk about sexually transmitted diseases. She also talks about sexual malfunction in women."
And so the modern saucy, sexy publication was born. Cosmo empowered women to embrace both their brains and their beauty.
Banner notes, "Helen Gurley Brown's message was never only about sex; it was about how you make your way in a modern world."
White says, "What Cosmo did (and this made feminism more palatable to a lot of women) is that it said: You could enjoy your life and have the life you wanted, but you could have a cute guy, too. I think some feminism was interpreted as being male bashing. I think a lot of women like the Cosmo take."
In 1974, Cosmo turned the tables, revealing much of Burt Reynolds in a jaw-dropping pose. While hot hunks remain a sizzling staple, the message continues to be that a woman can have it all. At 40, the Cosmo mantra "fun, fearless, female" is alive and well.
Banner says, "Fearless female who will confront the world, who will not be afraid of sexism or misogyny. So fun, fearless, female, that's good."
And as editor-in-chief, White says, "I try to take what Helen did, make it the bible for single women, stay with the times. I wasn't in the age group, so I've done a lot of research."
The mother of two teens says she does a lot of focus groups and reads every e-mail. But her secret weapon is her 15-year-old daughter.
"I show her every cover," White says. "I don't let her read the cover lines," which sometimes are a little spicy, though White disputes impressions that the magazine wants to push the envelope in terms of language.
"It's not just that you want to be so out there in terms of the content," White explains. "What Cosmo is all about is being fearless and feisty. You want to say there's a little hyperbole. You expect it to be out there."
And just by reading Cosmo, she says, her own marriage has improved.
"I think I'm a better wife because I'm reading Cosmo," White says. "I think I've understood when guys talk, they are very literal. When they say: 'Nothing is the matter' or, 'Yeah, I want Mexican food,' that's what they mean."
And the message is not just resonating in the United States. Cosmopolitan magazine is being published in many countries around the world.
"It is the biggest women's magazine in Russia and China," White says. "If we're the biggest in China, can democracy be far behind?"