Adsense is allowed on penis enlargement sites. I know, I own one and currently host adsense. I've even asked them, and it's okay as long as the site doesn't host anything pornish. I wouldn't even risk hosting a penis image.
I think google does not accept ad of this type. You can simply check it by entering your keyword in the google and see if any competitor is there. Also google simply states that it does not accept adult sites, so mostly there is no chance. But if you advertise under health keyword, you may have a chance. Ask google support, you get quick reply.
One of our friend says right, penis alone and vagina alone are not porn but google not allows these type of topics. So if you include the google adsense code google shows some ads related to health and in some days the account may be ban.
Bah, come on. Penis enlargement is as much "adult topic" as muscle enlargement and kegel exercises. Isn't the ads on the right hand side in google labeled "sponsored links" from adsense? Type "penis enlargement" in google and let the truth reveal itself!! Google has accepted my http://www.penis-wealth.com for years now. Would be very suprised if they suddenly changed their mind, as long as I stay away from penises, vaginas and the combination of the two.
Well since this is not categorized under porn but Health related I think it's allowed. But still it would be risky. I have seen Google ads in Adult health related sites so probbly this would be ok too. But The best thing is Ask AdSense support.