I purchased this with some skepticism about the claims made by other reviewers.  I have since found that all of these claims are true, and more.  Of note:

 - Gives you strength that would be the envy of even Samson, Hercules, Zeus, etc.
 - Increases your sexual appeal (warning: this applies to ALL living creatures, not just your gender of choice)
 - Causes significant amounts of hair growth (possibly a downside for some).
 - Maximizes your workouts.

(N.B. As a good, Amazon-loving reviewer, I should note that everything I have just said is false. This shirt exists purely as an ironic in-joke for the Internet culture crowd. You should buy it.)