If you have a look on Ben Greenfield’s personal website, it will tell you that he is a personal trainer, holistic nutritionist, and health expert, but given his latest stunt, he might want to retract that last section.

Greenfield is also one of a growing number of biohackers: a group of people who are not content to sit and wait quietly for the scientific community to open up medical procedures to the public after years of tests and regulatory processes. They are willing to put their own health and safety on the line – as long as it grants them a fast track to the latest science has to offer.

Some biohackers test out experimental medical treatments. Greenfield’s ambition is far more banal. He wants a bigger penis.

He told Gizmodo: “I wanted to go from good to great, and to get a bigger dick.”

In his latest effort to achieve this lofty ambition, Greenfield had his own stem cells injected into his penis during a procedure at Floridian biotech faculty, US Stem Cell, last November.

Relevant side note: The clinic received bad press last year after three patients taking part in an unproven stem cell therapy went blind. They also received warnings from the Food and Drug Agency (FDA) concerning “significant deviations”.

Earlier this month, Greenfield and Kristin Comella, Chief Science Officer at US Stem Cell, held a Q & A session via webinar to explain the treatment to a curious audience.

The process began by extracting stem cells in Greenfield’s fat cells. These were then injected straight into his penis.

“You don’t feel a thing other than a little bit of pressure,” he assured viewers.

But did the bizarre experiment work?

If you take Greenfield’s word for it, yes. Yes, it did.

“With penis injection … it took about 3 to 4 days to kick in and the main things I noticed were significant increase in erectile function, a significant increase in size in what we call 'at rest,' better orgasms, better blood flow -- the anatomical manifestations cannot be denied," the personal trainer revealed in a statement.

Though when asked by Gizmodo had he measured his penis to confirm the size change, he admitted: “I haven’t taken out a ruler”.

There is very good reason to remain skeptical. Yes, there has been some research to suggest stem cells can help men suffering from erectile dysfunction but trials are still in the early stages and there is diddly squat to say stem cells would have any effect on a healthy penis.  There is also the risk of infection and unknown side effects to consider, all for a procedure that probably won’t do very much.

But when it comes to "improving" their manhood, whether it's size or color, there seems very little some men won't try.