Does Red Bull have bull sperm in it? No, that's just a myth. Setting aside the grossness of that idea, it would offer zero nutritional value to the beverage. Not to mention, it would be extremely cost prohibitive to collect and produce for less than $2.50 per can!
This myth originates from one of the Red Bull drink ingredients; taurine. This is an organic compound that is found in most animals (including bulls) as well as humans. In fact in your own body, it is found within the bile of your large intestine and the total amount of taurine in you amounts to around 0.1% of your body weight. If you weigh 150 lbs that's about 2.4 ounces worth. The rumor was that the source of the taurine in the energy drink was harvested from the testicles of bulls. Perhaps it made for an interesting marketing angle but whatever the case, it is completely false.
Something else you won't find in Red Bull is antioxidants. Based on these test results, none are present. There is some nutritional value however in the form of the synthetically added vitamin B12 (80% of your daily value in 1 can), vitamin B6 (250%), niacin (100%), and pantothenic acid (50%). These are all B vitamins which have been extensively studied for their roles in energy metabolism so it makes sense as to why they are included in many energy drinks.
Research Support, Non-U.S. Gov't: Carlsen MH, Halvorsen BL, Holte K, et al. Nutrition Journal NIH Jan 2010