Thanks for your response Heather. I see what you mean; I think your estimate is probably right. I looked some stuff up and apparently they've been running trials for various types of male contraceptives for decades but they all get cancelled because of minor side effects, despite the fact that those side effects are actually less than that of the contraceptive pill which women regularly take.
It sounds to me like there's a lot of bias in the process of drug trials there. It's like they won't release a male contraceptive unless it's side-effect-free, even though the same effort is not being made to improve the female contraceptives which are already in common use.
https://www.lifehacker.com.au/2017/04/f ... et-to-use/
http://www.independent.co.uk/voices/mal ... 84601.html
But, there's a new male one called "Vasalgel" that people seem to be optimistic about, which is actually beginning human trials this year apparently. It's an injection into the vas deferens which kills or blocks sperm passing through with a high success rate. Sounds a bit strange but... that could be promising maybe? Although some people are saying funding is a problem and that pharmaceutical companies haven't been interested in male contraceptives because most of them are one-off "long-term", and thus make less money than regularly selling the female contraceptive pill. (1 Vasalgel shot works for years apparently, and can be reversed with another injection if need be, which sounds impressive) And also, with monkeys, it's had a 100% success rate with preventing pregnancy apparently! 100%. Few or no side effects were found too. I still feel skeptical that it might get shut down like all the others, but... who knows?
https://www.parsemus.org/projects/vasalgel/
http://www.dailymail.co.uk/news/article ... -rate.html
You probably know a lot of this already but still, this is an interesting topic to discuss. I didn't know much about it and I think more awareness really needs to be raised about it, for 2 reasons: more funding, and more men willing to volunteer for trials. Thanks for exposing me to all this, I'll continue to look into it. It's just a shame that there's nothing I can really do individually to help currently, and that there's nothing on the market yet to use. The vasalgel developers are non-profit so maybe I'll donate or something. I just want problems like this to be gone, contraception feels like a problem society should have definitively solved decades ago.
Thank you for answering my questions by the way; it was helpful to me.