I am a woman. I attempted suicide at age 17.
I went though my desk drawers, etc. I found some pills, maybe decongestants, and decided that would probably not kill me. I found an exacto knife in my art supplies and decided to cut my wrist with it. I failed to hit a major artery. There was very little blood.
In contrast, I believe my brother's room had a gun, a bow and an encyclopedia of true crime. Had he attempted suicide while locked in his room, there would have been dramatically greater access to effective means and useful information for actually ending up dead.
I will suggest that women generally have less access to effective means, generally have less exposure to subjects relevant to figuring out how to end a life, and that women are typically subjected to a greater amount of social control that limits their ability to act.
Men are more likely to be infantrymen, police officers, hunt as a hobby, etc. Thus, they are just more likely to know how to kill something.
Additionally, successful suicides occur when you are alone. Men seem to have more opportunities to actually be alone, an observation I made years ago on a different forum about a different subject.
Women typically make less money than men, so they are less likely to be able to afford a place of their own. They tend to have roommates. Following a divorce, women are more likely to get custody of the children. So, post divorce, men are more likely to be living alone, women are more likely to be living with kids.
Etc.
If you attempt suicide with other people at home, you need to keep it a secret. If they find out, they will stop you. Simply having other people around is a deterrent to succeeding. It is hard to very quietly, secretly off yourself.
So, I think one factor is that women are less likely to have sufficient privacy, for lack of a better word, to succeed.