It is true, of course, and well known: Sex shaped the soft core, hard times, and glory days of Helen Gurley Brown. Publicly, ever the coquette on Johnny Carson’s couch, she embraced the image. Privately, she held close the pain of her ascent — the astounding sexism, the slut-shaming leveled at an early sexual outlier, the male rats and reprobates she encountered along the way. Even close friends were unaware that the brazen, confident Cosmo girl relied on psychotherapy — with good humor — for 68 of her 90 years.

She did adore men, and was happy to let the carefree, ravishing legend stand. After all, sex had propelled Helen — a poor girl from the Arkansas Ozarks — into the publishing legend “HGB” when she loosed her incendiary best seller, Sex and the Single Girl, on the world in 1962. In her reassuring, big-sister prose, she was one of the first to suggest to single women, “Perhaps you will reconsider the idea that sex without marriage is dirty.” A few years later, sex helped her turn a moribund general-interest magazine, Cosmopolitan, into a hot women’s book that rescued the foundering Hearst Corporation. “Welcome the penis,” she urged her readers, a motto she lived by. Sex secured Helen’s advantageous marriage to movie producer David Brown and kept it “frisky” for half a century; sex built her wealth and shaped her public persona. Behind closed doors, sex thrilled and sustained her well into her eighth decade.

“Even in 1947, I knew it was okay to sleep with men and not be married to them,” she once said. “I’ve never been a revolutionary. I was just reporting what was true for me, true for my girlfriends.” But even as Helen relished her liberties as a single working woman in Los Angeles, her affairs caused her more pain than she ever let on. At girls’ “den nights” in her apartment, Helen would often find herself cheering up “the walking wounded.” They were all so vulnerable, these young women, she recalled. So was she, despite an astonishing roster of suitors. Her Mad Men career — Helen would become the most sought-after and highest-paid female advertising copywriter on the West Coast — spanned the period when she would become both a master of sex and a prisoner of love. Heartbreak, and its attendant depressions, cycled through those years. The feeling of being cheated on, the collapse of marriage dreams, those lonely-night “sads” fostered a torment Helen knew too well. In the bedroom and in the office, entrenched sexism bedeviled her. There were so many clear exit ramps for men and still so few rickety stepladders up and out for the women they left behind.

It was always worse for a poor girl. How badly — and baldly — Helen searched for a man to provide financial security. Her father had died in an elevator accident in Little Rock when she was 10; once her family moved to Los Angeles, 19-year-old Helen was helping to support her mother and pay crushing medical expenses for her sister, who was wheelchair-bound after a case of polio. Crammed into a gopher-ridden rental house hard by the railroad tracks, the Gurley women were desperate and dependent on Helen’s limited earning power. Her plan: “I had hoped to marry somebody wealthy and solve all my family’s and my problems. Alas, I didn’t have the credentials — looks, family background, emotional stability.”

Helen endured 17 lowly secretarial jobs before she found a foothold for a serious career in 1948. When she took the job as secretary to Don Belding, co-founder of the ad agency Foote, Cone & Belding (FC&B), she was still looking for her Main Chance. Helen, then 26, was cheered to find a roster of eligible men on staff. Years later she declared that with the exception of Cosmo, “I have never worked anywhere — and I’ve worked a lot of anywheres — without being sexually involved with somebody in the office.”

Yet she did not sleep her way from a secretary’s cubicle to an office with her name on the door and a copywriting job that found her directing Bogart and Bacall in a Catalina swimsuit ad. She wrote her way there, with the same direct and colloquial style she would later use to speak to her magazine readers. For that first important Catalina account, Helen clambered on the slippery rocks with Dixie cups of bourbon to warm model mermaids as they shivered in the dawn mists of Malibu. When the client requested “field work,” Miss Gurley barnstormed with a sales team nationwide, braving the dressing rooms of over 30 department stores to fit and sell Catalina swimsuits.

Along the way, her romantic flings effervesced, cooled, and sometimes collided. By her early 30s, Helen was feeling what she called “the power,” the peak of her sexual prowess. There was even an artistic rendering of Helen’s surging sexual wattage. She had a brief affair with an art director at FC&B, who was distressed to arrive at her apartment one day and find two other men already visiting. Then the artist got over it and began working on a comic tribute to Miss Gurley as the siren of Bonnie Brae Street. The drawing showed Helen’s bachelorette apartment building, with men hanging from the rafters, men falling out windows. The stairway was clogged with men; the street outside was beset by a traffic jam of suitors. Two women stood outside the building, taking in the mayhem. The caption had one saying to the other, “I think her name is Helen Gurley.” The piece was framed and later hung in the bathroom of Helen and David Brown’s Park Avenue apartment.

But despite her many conquests, a serial cheater had her heart all along; he tossed, dribbled, and drop-kicked it mercilessly for eight years. Helen nearly always referred to him as Don Juan or DJ. She wrote about him in a number of her memoirs and under several guises; he appears in Sex and the Single Girl as two different offenders. Only once, in an unpublished interview, did Helen mention his full name. In other writings she called him “Bill,” “W.G.,” or “Willie.” Helen described him as the creative director at a smaller ad agency, and “a real sex man.” She likened him to a Greek god, more than six feet tall with black, curly hair. He was two years older than Helen; she was 29 when they met.

By Helen’s description, DJ could have been the prototype for Mad Men’s Don Draper in his penchant for wreaking serial, unrepentant, idiosyncratic havoc on women. At first she was so besotted that she didn’t see the signs that he was a habitual heartbreaker. But eventually Helen came to realize that it pleased DJ greatly to have her know that there were other women, many, in his life. He had a compulsion to constantly “stick the shiv in,” as she put it.

In 1996, Helen went into further detail on her tormentor in a startlingly frank interview about her sexual history. “He was very romantic, the most romantic man you could possibly ever hope for in your whole life. I wanted to marry him. He would come back to me after a hiatus with the flowers, a Brooks Brothers shirt, the pen that says, ‘I have grey hair, brown eyes and a black heart.’ It was this wonderful sterling silver pen that he would have made. It was so cute. And rotten to the core. He would come back and he would say, ‘Okay, we’re going to be together, if everything goes well, we’ll get married.’ Idiot! I fell for it about three different times. He’d come back, we’d be in trouble, we’d break up again.”

She began to see how cunningly he planned his tortures. A cuter, much younger lover showed up banging on his apartment door while Helen was in his bed; gee, he’d thought that girl was still in Europe. He left letters from other women where she could find them. From snooping into one of them, Helen, a scant A cup, found that he had named a New York girlfriend’s generous breasts “Liebchen” and “Schatzi.” He bought gifts for his harem in multiples — the shirts, the pens — monogrammed for each. One Christmas, Helen saw stacks of these gifts in his apartment, marked for different women.

Many of his conquests were very wealthy, a fact he often mentioned to Helen, making her feel like “a nothingburger.” He extolled his ex-wife, her beauty, her Cordon Bleu cooking, her perfect ease as a hostess. Most cruelly, he belittled the thing that gave Helen the most self esteem, her so-called career. He was patronizing, mocking about her ad copy, as though she were a little girl playing at a big man’s game. Coming from a successful pro, the jabs struck hard.

Understandably, Helen developed some anger issues. When a blonde model walked by their table at the Santa Ynez Inn and greeted DJ, Helen poured a pitcher of water over his head in a spasm of jealousy. Objects began to fly and shatter; she threw a pitcher of icy gimlets, shoes, papers, books. Finding a letter in his glove compartment, she once screamed at him, “You’re seeing your wife again!” Then she took his car, parked it at the edge of the ocean, and refused to tell him where it was for three days. She sobbed, shrieked, and pleaded, sometimes for hours, to the point where only chugging a quart of milk could ease the hiccuping frenzy. DJ reveled in the drama; the more intense her agitation, the greater turn-on it was for him. His voice became calmer and sexier as he tried to soothe her. Silly girl ...

Helen saw herself as a prisoner of sex. “Whatever the emotional problems, I feel still that sex is such a dynamic incredible happening that your brains go bye-bye if you’re mad about this person,” she said. “You can’t be sensible, you can’t say, ‘Well, I’ll just sleep with him but I’ll go have somebody else who’s nice. I’ll marry somebody else and I’ll keep this person as a playmate.’ You can’t do that. If you’re sexually zonked, that’s it.”

Photograph by Susan Wood/Getty Images

She left DJ many times over those eight years, sometimes for as long as six months. During one hiatus in 1951, she had a dalliance with a high-ranking Army officer, Chester “Ted” Clifton, Jr., who later became senior military aide to President John F. Kennedy. Clifton was staying with his commander, General Omar Bradley, at the Beverly Hills Hotel. Helen’s boss, a friend and admirer of that war hero, had loaned his car, driver, and secretary to the general on his visit to L.A. Helen kibitzed poolside and typed the occasional memo; when Bradley retired for the evening, her covert maneuvers with Clifton began. They saw each other off and on for years, on two continents.

On another break from DJ, Helen had one of her more light-hearted and most public affairs, encouraged by her boss Don Belding, who thought it good for business. Prizefighter Jack Dempsey, 27 years her senior, was endorsing Bulldog Beer, the product of an FC&B client, Acme Brewing Company. Helen was 4 years old in 1926 when Dempsey’s heavyweight championship match with challenger Gene Tunney took up two-thirds of the New York Times front page. The bout, which Dempsey lost by unanimous decision, paid him an unheard-of $850,000 — about $11.3 million today. When Helen met him many years later, she declared him a “super stud,” still strong and rather voluble in the clinch. When close to the Moment, he was given to shouting, “Straighten me out, darling!” Said Helen, “Presumably, I did.”

On Dempsey’s arm at the Mocambo Club or Chasen’s, Helen popped up in the gossip columns, though usually as “unidentified brunette.” In time, the affair petered out. Helen was offended, though hardly heartbroken, when Dempsey suddenly decamped for New York to deal with a labor dispute at his eponymous restaurant and got himself engaged, briefly, to a rich widow. The Champ sent Helen a cheesecake.

DJ still pursued her relentlessly. To break her addiction to him, Helen turned to a new therapist who had developed the wildest, most demanding form of psychotherapy she had ever known. Charlie Cooke’s group practice met in an old house in Griffith Park a decade before the bloom of Esalen and other California-based, crawl-on-the-carpet paths to full selfhood. Helen cried a lot and endured excruciating group exercises, but finally, she walked away from DJ for good. By the time she turned 35, she had come to understand this: Sex and romance were too damned unpredictable. The workplace, despite its ups and downs, was a far safer bet. “Business I could rely on. It never went away and left you. It was not capricious. It did not go out with another girl. If you did good by it, it would be good by you.”

Her therapist had convinced Helen that she was ready for a good man, that she deserved love and security. “I think marriage is insurance for the worst years of your life,” she would write in Sex and the Single Girl. “During your best years you don’t need a husband. You do need a man of course every step of the way, and they are often emotionally cheaper and a lot more fun by the dozen.”

When her friend Ruth Schandorf told her about a solid prospect — a well-respected movie executive no less — the two women spun a marriage plot; it unfolded over nearly two years. It took a whole year just for Schandorf to determine that the man had finished chasing starlet wannabes and beachy airheads and was ready for a real relationship. Schandorf introduced Helen to David Brown at a small dinner party in 1958. Terrified of blowing it as she had with so many “possibles,” Helen barely spoke to him at dinner. He seemed interested and asked her out. Yet Helen sensed a vexing inertia on his part. It wasn’t surprising; he had been married twice, for 17 of his 42 years, to two stunning women who both walked out on him, leaving him alimony-poor in a pretty but rundown oceanfront home in Pacific Palisades.

For the longest time, David would not even give Helen his home phone number, forcing her to contact him through his answering service. In response, Helen turned up the sex. “He liked it,” she judged. Still, the courtship lurched along slowly. Every now and again David “misplaced” her, seemingly forgetting that they were an item. He continued to date others, and they broke up frequently. One night she was driving home after group therapy, waiting at a light on Santa Monica Boulevard when she saw David’s big white Chrysler 300, coming from Linden Drive. There was a blonde “smashed up against him” in the front seat.

Helen did not take his calls for the next day and night. When she finally did pick up the phone, they negotiated a limpid rapprochement. (David insisted the blonde was his business manager). Helen told herself that he was really an okay guy, “just frisking around.” She was not deeply, romantically in love; she was hardly as obsessed as she had been with DJ. Yet she was taken with David, even told herself that she kind of adored him. And at 37, it was time to marry. So she started to push again. A ring, please.

One night he pushed back. He said he just couldn’t marry again. Helen told him — calmly this time — that she understood, but that it was over. He was not to call her again. She went home and cried. The following morning at 8 a.m., teary and bereft, she laced up her sneakers and set out for her favorite place to be alone, Will Rogers State Park. She climbed up to the vista at Inspiration Point. When she trudged back to the parking lot, there stood David beside his Chrysler. He knew exactly where to find his distraught health nut.

“Come on home,” he said. “We’ll work it out.”

During that summer of 1959, their marriage plans were on and off at least five times by Helen’s reckoning. He finally agreed to marry that September. Even if he hadn’t forbidden her to tell anyone, Helen would have stayed mum. “I didn’t want to get the train that far and have it derail with some extravaganza. What if he got cold feet and didn’t show up? No, we did it David’s way, just a judge and his secretary as witness.”

That afternoon, September 25, 1959, David had quietly left work at the 20th Century Fox studios early, telling his boss, “I’m taking off for a couple of hours, see you Monday.” They were married at Beverly Hills City Hall. Afterward, they went to dinner with screenwriter Ernest Lehman and his wife, Jackie, then to the Largo strip club to catch the spectacular and athletic Candy Barr. Helen judged her “a damned fine stripper.”

Against all odds, Helen Gurley had married the love of her life. The marriage would last 51 years, ending with David’s death in 2010. Together, they mined Helen’s single-girl adventures into books, a movie, Cosmopolitan. He wrote the outrageous Cosmo cover lines; Helen did the shameless logrolling for his films — from Butch Cassidy and the Sundance Kid to The Sting and Jaws. They lived a vibrant, exciting life, compiled a fortune in the hundreds of millions and left it to educational charities. It wasn’t always smooth; Helen still had a temper. She bent spoons in half at boring events in hotel ballrooms and handed them to her husband beneath the table to signal, “We’re outta here!” — or else. David was aghast when she indulged in breast augmentation at age 73; he had adored her lovely small set, he told friends.

For years, well into her 80s, Helen maintained a correspondence with her tormentor, DJ, who was also long married. Their communication was mainly one-sided; he often sent random bloviations to friends and acquaintances. It is clear from their correspondence that, despite a couple of crass propositions, Helen never fell back into his arms and had not seen him in decades. A photograph tucked into one of his letters is of a silver-haired popinjay in a three-piece white suit. Helen showed it to her closest friend and former FC&B co-worker, Charlotte Veal, who had watched the couple’s miserable tango so long ago. Helen told Charlotte: I had David. Whatever had I seen in that one?

Adapted from Not Pretty Enough: The Unlikely Triumph of Helen Gurley Brown by Gerri Hirshey, to be published July 2016 by Sarah Crichton Books.