Men account for the most suicide completions, but women make the most attempts by a factor of four to one.
The reason so many more women make failed attempts at suicide than men is the subject of ongoing debate. But the lethality of the chosen mode of suicide probably accounts for much of the difference. Firearms, which offer little prospect of survival, account for 78% of male suicides and only 35% of female suicides.
The standard assumption that people who fail at suicide attempts are less determined in their efforts and more ambiguous about dying than those who complete the act continues to be widely held. There is, in fact, a third class of suicidal behavior, called suicide gesture – reserved by some experts for those whose actions and plans are unlikely to prove successful
However, between more determined attempted suicides and those carried to completion, there are suggestions that choice of methods  may be a significant factor.
Women typically attempt to poison themselves, either with drugs or non-pharmaceutical chemicals. In this country, with access to high-powered poisons restricted by law, and ready access to sophisticated resuscitation techniques, the proportion of failed poisoning attempts is quite high, and women die far less often than men, who typically choose firearms. In countries where access to highly lethal poisons is less restricted, more women than men complete their suicide attempts. 
Further, there a logical flaw inherent in any effort to assess relative intent by outcome. The seriousness of the attempter who succeeds in taking his or her own life relative to that of one who failed is not measurable. And the seriousness of the failed attempter is mitigated in his or her own mind by the opportunity to reconsider. There is evolving evidence that a dissociative state that psychologist Richard Heckler dubbed “the suicidal trance” permits the attempter to arrange and carry out the effort at self-destruction with little or no psychological resistance or opportunity to appeal to rational judgment. 
Another prominent suicide researcher describes the psychological state preceding a suicide attempt as being like
“…the unanswerable logic of a nightmare, or like the science-fiction fantasy of being projected suddenly into another dimension: everything makes sense and follows its own strict rules; yet at the same time, everything is also different, perverted, upside down. Once a man decides to take his own life he enters a shut-off, impregnable but wholly convincing world where every detail fits and each incident reinforces his decision." 
Only 20 percent of those who fail in suicide attempts try again within one year, and only 10 percent complete the act, even though only about half receive post-attempt treatment.  so second attempts are comparatively rare and the sincerity of the first attempt must remain in question.
 Commentary: Suicide in Women, The Lancet, Vol. 355, Number 9211, 08 April 2000.
 Heckler, Richard A., Waking Up Alive, Ballantine Books, 1966
Alvarez, The Savage God: A Study of Suicide (New York: Random House, 1970), 121.