Jon Jones' current fight is taking place inside laboratories and administrative buildings.

MMA's pound-for-pound king tested positive for two banned substance before UFC 200 and was pulled from the card just three days before his main event title fight against Daniel Cormier was supposed to go off. Now, Jones will have to go through the appeal process with both USADA, the UFC's anti-doping partner, and the Nevada Athletic Commission (NAC).

On Monday, the NAC released the names of the two substances found in Jones' system in the June 16 sample collected by USADA: hydroxy-clomiphene (or Clomid) and Letrozole. Both are estrogen blockers.

Jones, who turns 29 on Tuesday, responded on Twitter by continuing to deny being a cheater. Jones tweeted that he was having products sent to a lab to be tested, presumably in an attempt to clear his name. Jones also wrote this situation could have been "prevented" and he was a victim of his own ignorance. It appears that "Bones" and his team will claim that the longtime champion ingested a tainted supplement, which led to the positive test.

I'll disclose to the public when I find out, already sent products to a lab. I have nothing to hide https://t.co/yHjtiDPlEq — Jon Bones Jones (@JonnyBones) July 18, 2016

Not trying 2 come across as a victim if anything Im a victim of my own ignorance & yes this could've been prevented https://t.co/bM0FTB5A9B — Jon Bones Jones (@JonnyBones) July 18, 2016

The drug clomiphene is used medically to treat infertility in women. So why would it be found in an athlete? Well, the agent quells estrogen, while stimulating testosterone production. Doctors have prescribed it for hypogonadism (clinically low testosterone) in men, much like the much-maligned testosterone replacement therapy (TRT).

Clomiphene is cheaper than TRT, has fewer side effects and is more convenient to take. It's a pill; no injections needed. It can also can be used to enhance male virility and sexual performance.

"So instead of taking TRT, Clomid can assist in accomplishing a similar response," said Dr. Margaret Goodman, president of the Voluntary Anti-Doping Agency (VADA). "Men have taken it to improve fertility. Bottom line, it's a banned substance at all times, and an athlete would require a [therapeutic use exemption] to use it."

Clomiphene has also been referred to as a post-cycle therapy (PCT) drug. In other words, it's something men take after using anabolic steroids in order to get their natural testosterone levels higher.

Letrozole is a substance known as an aromatase inhibitor. Aromatase is the substance in our bodies that converts testosterone into estrogen. Letrozole suppresses aromatase, which leaves more natural testosterone in the system. Clinically, it is used to treat breast-cancer patients. But for men, it works in much the same way clomiphene does and with even fewer side effects.

"I like to think of certain banned substances like Clomid and Letrozole as indirect roads to the same destination, thereby increasing testosterone irrespective of why it was being used or prescribed," Goodman said.

If Jones does go with a tainted supplement defense, he could have a case.

Oliver Catlin, the president and founder of the supplement-certifying company Banned Substances Control Group, said the Food and Drug Administration (FDA) has done very little testing on over-the-counter estrogen blocker supplements and very few of those products are certified. However, Catlin said, the supplement industry is rampant with contaminated products, either accidentally or intentionally. The anti-estrogen category is likely no different.

"There hasn't been a demonstration in the industry experience that Letrozol and clomiphene can show up as a contaminating substances," Catlin said. "From my experience, I believe that there very much is a significant possibility for anti-estrogen supplements to be contaminated with [banned] pharmaceutical anti-estrogens."

And the chance is even greater if Jones went to a place like GNC and picked up a supposed natural estrogen blocker, Catlin said. It's relatively common, he said, for products like that to be spiked with a banned substance that makes the supplement more effective.

"Really, you don't know that the supplement you're using or not is tested and that's the very point," he said. "Knowing there is a risk of anything, any supplement that is in a category that is banned in sport runs a potential risk of being contaminated with a pharmaceutical drug that's not on the label showing up in that product to make it work better. And that's across the board of categories — whether it's a natural testosterone booster, an aromatase inhibitor."

Part of UFC vice president of athlete health and performance Jeff Novitzky's job is to receive e-mails and text messages from fighters about their supplements. Novitzky can check with USADA and let a fighter know if their supplements are at risk or not. But, Novitzky told MMA Fighting earlier this year, he can never say he is 100 percent sure because of the nature of supplements and cross-contamination.

Jones said he's already having products he ingested tested, presumably for substances that were not on the label. If he can prove to USADA that the drugs he popped for are from a tainted supplement, Jones could get a six-month suspension, much like Yoel Romero and Tim Means, who were in a similar situation. If Jones can't, he could be facing a two-year ban from USADA.

Jones has good legal representation: leading athlete lawyer Howard Jacobs, who has served as counsel for the the likes of Marion Jones, Diana Taurasi and Floyd Landis. He was called "drug-testing's version of Johnnie Cochran" in a 2006 USA Today profile.

Both USADA and the NAC have jurisdiction over this case. Both can hand Jones separate sanctions. Jones is likely to go before the NAC in September or October for a disciplinary hearing.

The NAC is in the process of passing new guidelines for discipline with regard to drug offenders. Under the potential new policy, first-time steroid or testosterone offenders would receive three-year suspensions and a fine of 50 to 75 percent of their purse. It's unclear if the policy would be retroactive to cases, like Jones', that occurred before it was passed.