Mark Cuban is an ideas man, and he's got a hell of an idea. In late November, Cuban announced that he had asked the NBA Board of Governors to consider letting injured players use synthetic human growth hormone (HGH) while rehabbing and that he was willing to fund the necessary clinical studies to ensure player safety himself. I was intrigued, and I wasn't the only one.


"They're open-minded," Cuban said, referring to the Board of Governors. "Knowing that it'll take 10 years to get [the studies] done, it's easy to be open-minded and say when it's there, it's there. But hopefully it's something I can accelerate. I've talked to a couple of different universities about funding studies."

Cuban compared HGH use to Tommy John surgery, in which the ulnar collateral ligament in the elbow is replaced with a tendon from elsewhere in the body. The procedure often allows pitchers to return to the mound throwing harder than they did before surgery, and there's long been speculation that in the future, players will have the surgery preemptively, to gain a competitive advantage. But that would require an orthopedic surgeon willing to operate on an otherwise healthy individual, which seems unlikely (for now). HGH, on the other hand, can simply be prescribed by a physician and administered like any other medication, which means the potential for abuse is far greater.


What does HGH do?

But before we decide on the merits of Cuban's idea, it's important to provide some context. HGH is a naturally occurring hormone that the body makes and stores in the anterior pituitary gland of the brain. Release of the hormone can be stimulated by sleep, exercise, and nutrition, and can be inhibited by things like insulin. A complex interplay of physiological factors and hormones ensures that most people have just the right amount of HGH floating in the blood stream. But some people—like the world's best soccer player, Lionel Messi—don't, which causes them to be short, and can also cause delayed sexual maturity. It isn't controversial to treat people with a similar physiological makeup to Messi; they have a deficiency of HGH and require a synthetic replacement.1

The controversial part is giving HGH to people who don't have a deficiency. A landmark study performed several years ago in Sydney, Australia showed just how powerful HGH is. Researchers there assigned 103 recreational athletes ages 18 to 40 into four treatment groups: 1) HGH, 2) Testosterone, 3) HGH with testosterone, or 4) Placebo. The study found that HGH users saw a 4-5% increase in speed on a bicycle, while testosterone users had an 8% increase. The study, which was funded by the World Anti-Doping Agency, also found that in a hundred meter dash, sprinters using HGH had a 0.4-second improvement in their times. (These figures will obviously shift based on where an athlete is as they begin using HGH.) Understandably, HGH remains banned from competitive sport; it simply provides an unfair competitive advantage, allowing athletes to achieve feats that weren't previously attainable. Think of it as Testosterone Lite.

How does it help heal?

But what about injured athletes—athletes like Andy Pettitte, who reluctantly admitted to using HGH for two days while rehabbing an elbow injury? Was he placing himself at an unfair competitive advantage? Or was he simply being a good teammate, trying to get back on the mound as quickly as possible? Medically, that's a little more complicated.


Several studies have shown that HGH can improve healing, but it's important to realize that HGH isn't a panacea that repairs all wounds. The hormone is especially promising for bone growth and fracture repair (particularly hip fractures), but its use in tendon injuries is questionable and its use in tendon-bone interface injuries (a rotator cuff repair, for instance) may actually be harmful. Moreover, excessive HGH use can conceivably contribute to tumor growth. The key to all of this is that there are many molecules that can help the body heal but those that confer an athletic advantage (like HGH) should be banned. Those that don't (like platelet rich plasma therapy) should not.

But Mark Cuban—The Ideas Man—insists that it's not that simple. He also suggests he doesn't have an agenda (although his tendency toward players who age gracefully and remain efficient, like Dirk, Jason Kidd, or Shawn Marion would suggest at least a little otherwise). He just wants to see if HGH can get players back on the court more quickly, which would ultimately benefit everyone—fans, owners, and players.


"The issue isn't whether I think it should be used," Cuban told USA TODAY Sports via e-mail. "The issue is that it has not been approved for such use. And one of the reasons it hasn't been approved is that there have not been studies done to prove the benefits of prescribing HGH for athletic rehabilitation or any injury rehabilitation that I'm aware of."

So how would this work?

Even if Cuban and the NBA are able to show that HGH use is safe for its ailing players, the league will need to ask itself an important, seemingly obvious question: How does one define "injured"? Must a player be on the disabled list to receive HGH? And for how long? Is HGH use at the discretion of the team physician or is a second opinion required? And does that create a conflict of interest since the doctor is employed by the team?


It's pointless to go over all the variables; just know that jumping through loopholes would be basically mandatory. The off-season would become a time to ingest as much human growth hormone as possible, or as much as a team doctor will allow. It would immediately recall baseball's Steroid Era, where every feat of strength was viewed with skepticism.

But the path to HGH approval could follow that of caffeine, a substance that was identified as a performance enhancer decades ago and was formally banned by the World Anti-Doping Agency and the International Olympic Committee in 1984. Subsequent testing revealed that the performance enhancing-effects only occurred at above a certain threshold and the ban was lifted in 2004. The previously banned asthma drug formoterol followed a similar path to approval after a therapeutic dose was deemed safe for use in athletic competition in 2011. It's important to remember that the list of banned substances remains fluid and what we consider cheating today might be viewed differently a few years from now. It will be up to Mark Cuban's scientists to determine if there is a threshold under which HGH can be safely administered without compromising the integrity athletic competition.


If I had to look into the future, I'd bet very low-dose HGH use will become a common treatment for injured professional athletes a generation from now. There's simply too much money at stake to let superstar players sit on the sidelines, and we've seen that athletes are will to try all sorts of unusual treatments to get back on the court more quickly. Cuban's studies—or if his never get off the ground, someone else's—will probably identify a safe dose of HGH (a dose much smaller than what is used now) that will demonstrate a modest improvement in rehabilitation times without substantially improving athletic performance.

Even if you take all that as a given, you're still left the biggest hurdle: just how crazy teams, in any sport, can be about player health. So once some form of HGH is cleared for medicinal use, how do you enforce teams for using it the correct way, and on the correct patients? The real fight will be over prescribing privileges—and at a bare minimum, the team physician should be barred from doling out HGH. The conflict of interest and potential for abuse would simply be too great.


But as a whole? The capacity for HGH to help injured athletes heal from legitimate injuries is too alluring to not look into its use in pro sports.


1 The controversy arises when those patients develop into athletic superstars. Messi was diagnosed with growth hormone deficiency at age 11, when he was just 4'2.


Matt McCarthy is board-certified in internal medicine. You can follow him on Twitter here.