When sex researcher Rachel K. Jones published a report that suggests the much-maligned withdrawal method of birth control was nearly as effective as condoms in preventing pregnancy, she was showered with criticism.
And it wasn't evangelicals who had taken virginity pledges who pulled out the big guns.
Those whom Jones said could benefit from this information -- couples in monogamous relationships who are not at risk for sexually transmitted diseases -- reacted in "sheer disbelief," she said.
"I don't know anybody who does the 'pull out' method, as we call it," said one 23-year-old who is in a monogamous relationship but didn't want her name used. "Most of us have had enough sex education courses to know that doesn't work very well."
The act of withdrawal -- the male pulling out before ejaculation -- is a long controversial method of birth control, one many sex education classes have condemned as risky.
But Jones' findings, based on several studies and data from the Guttmacher Institute , a nonprofit organization focused on sexual and reproductive health where she is a senior research associate, were just the opposite.
Her studies found that in perfect use -- meaning the man pulls out every time -- withdrawal has a 4 percent failure rate, as compared to condoms, which have a 2 percent failure rate.
"But nobody's perfect," said Jones, who published her commentary in the June issue of Contraception magazine.
In typical use, when used consistently and correctly, coitus interruptus and condoms have an 18 and 17 percent failure rate, respectively.
"Although withdrawal may not be as effective as some contraceptive methods, it is substantially more effective than nothing," said the report. "It is also convenient, requires no prior planning and there is no cost involved."
Jones noted that one persistent myth often cited as a drawback to withdrawal -- that there is mobile sperm in pre-ejaculate -- is actually contradicted by two studies cited by the National Institutes of Health.
"In two small studies there is no sperm in the fluid," she said. "If the guy has had sex in the last couple of hours is the only way it gets in pre-cum. But if you go to the bathroom, it flushes the sperm out."
"Withdrawal gets a bad rap," according to Jones, who urges sex educators and health professionals to discuss the method when teaching about birth control.
Her research set off fireworks in the blogosphere as both women and men assailed the withdrawal method as "reproductive roulette."
On Jezebel.com, which reports on celebrity, sex and fashion for women, a blog on the study had nearly 14,000 pages views and 337 comments, out-performing its popular column, "Slutty Feminists."
"Yeah," wrote Macloserboy. "The very fact I'm even writing this is proof it doesn't work. Thanks dad, for sharing that piece of information in a drunken, bonding moment 30 years ago."
"Should we start dropping off products of failed withdrawal techniques at the local ATM?" asked fireflyinjuly.
"A co-worker of mine refers to this as the 'pull and pray' method," wrote one commenter, saintbernadette.
Even sex educators like Dr. Judy Kuriansky from Columbia University's Teachers College said that "very little could be worse."
"Teens will misuse the data and boys will use it as an excuse not to wear condoms," she told ABCNews.com. "It is also not good for monogamous couples, especially those who are religious and against abortion, who may have more unplanned pregnancies."
Jones, surprised by the thrust of her critics, responded with a letter she hoped would be widely published.
"I've grown used to promoters of abstinence only-until-marriage programs dismissing the effectiveness of contraception," said Jones. "However, I'm surprised to see such disparagement of withdrawal among a crowd that is presumably younger, more diverse and open-minded."
"Perhaps because most of us have been told for so long that withdrawal doesn't work, we are unable to embrace scientific evidence that counters what we 'know,'" said Jones.
Despite the explosive reaction, statistics suggest that most women have used withdrawal.
According to the 2002 National Survey of Family Growth, 56 percent of all sexually experienced women rely on withdrawal at some time during their lives. About 82 percent have used the pill and 90 percent a condom.
The Women's Well-Being and Sexuality Study found that 21 percent of younger and more educated women were using withdrawal.
Dr. Melissa Gilliam, chief of family planning and contraceptive research at the University of Chicago, worries that sexually active teens might get confusing messages if withdrawal were promoted as an option.
"It clearly has a high failure rate," she told ABCNews.com. "It should only be used as a stop-gap measure or as emergency protection."
Jones notes that hormones and the IUD (intra-uterine device) are the most effective forms of birth control. But many women can't use these longer lasting methods, and many can't afford them.
Birth control pills are typically not covered by health insurance plans and can cost $20 to $50 a month. An IUD, which lasts for up to a decade, can cost several hundred dollars for insertion at a doctor's office.
"My practice is in pediatric adolescence, and I prescribe at lot of birth control for medical and contraceptive reasons," said Gilliam, who sits on the board of the Guttmacher Institute. "But even with highly effective methods there are a lot of issues of adherence. The more complex the message the more confusing it's bound to be."
She recommends "belts and suspenders" or "double Dutch," meaning both a highly effective method like pills, an IUD, injections or implants, as well as condoms to protect from infections.
An estimated 25 percent of all teens have a sexually transmitted infection, according to the CDC.
"When you are dealing with those numbers and pregnancy, it's very different message than for monogamous older couples who already have lower rates of fertility," Gilliam said.
Jones agreed teens need comprehensive information on sex.
"Anecdotally, some are using [withdrawal], and we needed to know how effective it is or not," she said. "In certain situations, it's most effective."
"If you can't take hormones, it's better than nothing," Jones said. "It's a back-up method if you forget to take pills or there are no condoms around."
Many women say that a birth control method that relies on the will-power of a man is doomed to fail, a problem that could be particularly evident with teens.
Heather Corinna, the founder of ScarletTeen, a Web site that discusses "sex education for the real world," said younger men have "less awareness and control" over ejaculation.
"And if we're being really forthright, we also can safely say [withdrawal] is probably the most-sabotaged method by male partners," Corinna told Salon.com.
"In other words, it's the one male partners will most often agree to, then not comply with, either by talking a female partner into just letting them ejaculate, or by saying they did so on accident when it wasn't at all accidental," she said.
But Jones suggested it wasn't fair to say that men can't be counted on to act responsibly.
"Most interesting is the response that many men can't be trusted in the heat of the moment," she said. "Sometimes it seems men can't win for losing when it comes to sexual and reproductive health. We argue that contraceptive is a couples' issue, that women should not be solely responsible, yet we don't think men can handle the responsibility."
Megan Carpentier, who wrote the Jezebel blog, "Can We Stop Shaming Women Who Practice Withdrawal Now?" argued that although the method may not work for every couple, her reader reaction illustrates the "real lack of knowledge" women have about their bodies.
"We are told only that every 28 days you bleed and you could be fertile at any time," she said. "It's a scare tactic."
"Every method requires knowledge and responsibility," said Carpentier. "Most women aren't given enough information and are scared of their bodies."
The Guttmacher report, she said, lifted the stigma that surrounded a couple's choice to use withdrawal.
"There aren't only three methods to have responsible sex," said Carpentier.
One of her readers, EvieB agreed.
Unemployed without insurance, she said she'd had "horrible experiences" with hormones and condoms.
"The withdrawal method has worked very well for me, and I'm glad to see that there is research being done to show that it's not as ineffective as people might think," said EvieB. "And maybe now I won't be seen as completely responsible for using it."