An Endocrinologists’ Perspective on the Big Foot Silva Story


Antonio ‘Big Foot’ Silva has received a 9 month suspension and has been forced to forfeit his Fight of the Night Bonus for testing positive for elevated levels of testosterone. As a Board Certified Endocrinologist, I believe that there are many scenarios that may explain this outcome. First, testosterone can be administered via a transdermal, oral or intramuscular route. The only feasible approach for a UFC fighter with a Therapeutic Exemption for TRT would be with intramuscular injections of testosterone, either enanthate or cypionate formulations. A peak in testosterone levels will occur 2-5 days after an injection and reach a nadir at roughly 13-14 days after injection. According to Silva, he was advised by his physician to inject an additional dose of testosterone after being notified that his “levels are still low.” Silva injected a dose of testosterone seven days prior to the event and then an additional dose during fight week. The peak in testosterone levels that occurs 2-5 days after an injection is typically well above the reference range. Thus, I would not be surprised if Silva’s testosterone level was well above 1200ng/dL if he had an additional injection between 2 and 5 days prior to his examination. An accurate assessment of testosterone levels can only be made at least 7 days after the last testosterone injection. Serum testosterone levels will cycle between “too high” (2-5 days after injection) and “too low” (13-14 days after injection) in individuals receiving intramuscular injections.

Secondly, why were Silva’s testosterone levels “too low” one week prior to his fight?? The obvious answer is weight cutting. Bigfoot actually has to cut weight to make the 265 lb limit. Rapid weight cutting does cause a decline in testosterone levels and thus, a sudden increase in his dosage combined with a restoration to his baseline body weight resulted in a supratherapeutic testosterone level.

Big Foot Silva was following his doctor’s orders. Elevated testosterone levels is a common occurrence in individuals, including fighters on TRT. It all depends on the timing of the testosterone examination in relation to their intramuscular injections. Antonio Silva should not have been suspended and his Fight of the Night Bonus shall be returned to him.