because i'm a nerd...

[zhenggy]

http://www.nytimes.com/2009/04/21/science/21horse.html?hp

Dr. Kirkpatrick, 69, has been using the birth control drug porcine zona pellucida, or P.Z.P., since 1988 to control horse and deer populations. He has been promoting its use for the federal government’s

Comments

[autumnmist]

Because the reversibility isn't known/understood/100%. And very few human males are going to willingly use as temporary BC something that might make them sterile. And men who want to be sterile just get their vas cut.

[autumnmist]

also issues of cross-reaction to the actual tissue and not just the sperm/end-product.

[zhenggy]

Well it sounds like they're just injecting the ZP of a different animal into females, forcing the females to produce antibodies against it (and the female's own ZP), so that fertilization can't take place. The article says it lasts a year, so it's definitely not permanent.

I'm just surprised that there hasn't been any interest in adapting this for humans. I mean, non-hormonal birth control that lasts a year? Just one injection? Besides the IUD, what else could do that?

[autumnmist]

There is interest... they've been trying for decades to get it safely and effectively working in human males.

[autumnmist]

http://en.wikipedia.org/wiki/Male_contraceptive
http://malecontraceptives.org/methods/index.php

Lots of research has been done (you just have to go reading the scientific literature for it--it doesn't get a lot of mainstream media publicity) but a number of methods haven't panned out due to the issues I mentioned. The article says a year... and they don't know for sure that it's 100% reversible in all individuals. The immune system isn't something you want to play with like that without a lot of clinical trials.