～もん

Hello~

I'd like to know what the ending ～もん means/ implies.
Further I have the feeling that it is more used by men, since I only heard men using it so far.
I hope someone could enlighten me.

Thank you in advance

The sentence-final particle もん is mainly used to explain the reason of the speaker's words/actions/feelings or to make excuses.

なんで昨日来なかったの？(Nande kinou konakatta no?)
Why didn't you come yesterday?

頭が痛かったんだもん。(Atama ga itakattanda mon.)
Because I had a headache.

While もの is basically used only by female, もん can be used by both male and female. Some forms might sound feminine(e.g. なんだもん,) though.

hope this helps

Thank you very much Toritoribe!
I really love Japanese for those little words, though it can be confusing at times.