[myboobs]

I thought that effect is from maka!

It's probably not as known for it, but it's no secret to BB's and PS's.

Most male enhancement supplements contain L-arginine, a semi-essential amino acid known as the precursor to nitric oxide, the natural compound that is responsible for your erections. Nitric oxide-boosting supplements are used by athletes and bodybuilders to build muscle. Porn stars use natural penis pills that contain increase nitric oxide production to make sure that their erections last long enough for them to complete their scenes.
Aside from L-arginine, male enhancement supplements contain herbs, nutrients, and other natural substances that increase the flow of blood to the penis, increase testosterone levels, improve sperm quality, and support overall sexual health.

http://healthcaremag.blogspot.com/2012/09/are-male-enhancement-supplements-secret.html

Wow !! Didn't know that