Ryan Howard, Peyton Manning and Ryan Zimmerman denied claims made in a recent Al Jazeera documentary. (Dan Worthington/Washington Post illustration; Getty Images/Getty Images)

The Guyer Institute of Molecular Medicine is an Indianapolis anti-aging clinic where wealthy women go for Botox, fat-freezing and hormone replacement therapy. It is also where Peyton Manning went for treatment in 2011 as he tried to recover from neck surgery.

Rejuvenate You Wellness & Anti-Aging Center is a Bradenton, Fla., clinic that advertises weight-loss drugs, therapeutic facials and hormone replacement therapy. The anti-aging doctor who runs it also has treated professional athletes such as Green Bay Packers linebacker Mike Neal, Philadelphia Phillies first baseman Ryan Howard and Washington Nationals third baseman Ryan Zimmerman.

Manning, Neal, Howard and Zimmerman have something else in common: They were all accused of taking banned drugs in the Al Jazeera documentary “The Dark Side: The Secret World of Sports Doping.” All four have denied the claims, and the documentary’s main source, who was recorded without his knowledge, has recanted everything he said.

The NFL and Major League Baseball are investigating the claims in the documentary nonetheless. Chief among the questions investigators will try to answer is one that has persisted among anti-doping experts since the documentary aired: Why would a professional athlete visit an anti-aging clinic?

Anti-aging medicine is a controversial industry based on the belief that aging is a disease that can be treated by substances such as testosterone, human growth hormone and DHEA — all of which are universally banned performance-enhancing drugs in professional sports. A bevy of doping scandals involving anti-aging doctors — most notably baseball’s Biogenesis case — has created an enduring stigma.

“Should we be suspicious about elite athletes who visit anti-aging clinics? Yes,” said John Hoberman, a University of Texas historian and doping expert. “You simply don’t know what is offered inside that clinic. And there is so much evidence that the people who run these clinics are willing to bend the rules and break the law and undertake all sorts of experimental procedures about which they know little or nothing.”

Manning’s spokesman — former White House press secretary Ari Fleischer, a crisis management consultant the quarterback hired after learning of the documentary — said Manning was unaware the Guyer Institute was an anti-aging clinic when he was a patient. Manning only decided to go there, Fleischer said, because he wanted to try the clinic’s hyperbaric chamber.

“Peyton says, with some emotion, that this was not an anti-aging facility,” Fleischer said. “It was a place he went that had a hyperbaric chamber.”

The Florida anti-aging doctor who treated Neal, Howard and Zimmerman — George Bino Rucker — said he has never provided an athlete with a banned substance. Rucker was not named in “The Dark Side,” but he has a personal connection to the documentary’s main source, aspiring pharmacist Charlie Sly.

Rucker is a friend of professional trainer Jason Riley, Sly’s former business partner. In a now-removed Instagram video from 2013, Sly is shown injecting Rucker with a substance Rucker said was a pain-killer. Rucker claims he has met Sly only once, that day Sly injected him.

Neal and his agent did not reply to multiple requests to comment. Howard and Zimmerman, through their lawyers, declined to comment.

A person familiar with Howard and Zimmerman’s defamation lawsuits against Al Jazeera said the players have said their trainer, Riley, referred them to Rucker, and the anti-aging doctor treated them only once “to draw blood.”

“As far as they knew he was a doctor, connected to Riley, and he drew blood,” said the person, who spoke on the condition of anonymity. “They don’t have any recollection of who he was or what it was for . . . but these guys did not, in any way, consult with this doctor for anti-aging.”

The Guyer Institute of Molecular Medicine is where Peyton Manning visited while he recovered from a neck injury in 2011. (Katherine Frey/The Washington Post)
The anti-aging era

A few months before a documentary alleged his clinic shipped human growth hormone to Manning, Leonard “Dale” Guyer appeared in an infomercial.

“It’s a unique time in the practice of medicine,” said Guyer, a cherubic 55-year-old in pinstriped purple. “Ours is really the first generation we’ve had these very powerful tools to really preserve or kind of streamline the aging experience. You don’t have to gain weight; you don’t have to have hot flashes; you can preserve your immune health . . . It’s all about the synergy, putting all the hormones together.”

The “unique time” Guyer referred to is the era of anti-aging medicine. Since it came into prominence in the 1990s, anti-aging medicine has grown into a booming business, with “wellness” and “rejuvenation” clinics dotting the country. Recent industry estimates value annual sales of anti-aging products at more than $100 billion.

The Florida-based American Academy of Anti-Aging Medicine, which reports it represents 26,000 physicians and scientists around the globe, did not respond to numerous requests to comment for this story. The industry has been dogged by detractors in the medical world who say anti-aging doctors overstate benefits and understate risks of often expensive treatments.

Anti-aging treatments such as hormone therapy can cost hundreds or thousands of dollars per month and are rarely covered by insurance.

“It’s a business, not a medical specialty,” said Alan Rogol, a pediatric endocrinologist and professor at the University of Virginia School of Medicine. “They make a ton of money from people who think age is such a bad deal in their life that they will do anything to anti-age.”

Anti-aging doctors and clinics also have played recurring roles in a long string of sports doping scandals.

In 2007, when authorities raided the Palm Beach Rejuvenation Center in Florida, they uncovered a list of athlete clients including former New England Patriots safety Rodney Harrison and former San Francisco Giants third baseman (and former Nationals manager) Matt Williams. Both admitted to taking HGH.

In 2008, California anti-aging doctor Ramon Scruggs was indicted on charges he illegally prescribed HGH and steroids to patients including former MLB players Troy Glaus and Scott Schoeneweis.

“I really believe anabolic steroids and natural hormone replacement therapy are the best way to get health back at a certain age,” Scruggs said in a 2009 New York Times interview.

Then came the 2013 case that is arguably the worst drug cheating scandal in major American sports: Biogenesis. The Coral Gables, Fla., anti-aging clinic provided banned drugs to at least 13 MLB players, including stars Alex Rodriguez, Ryan Braun and Nelson Cruz. Biogenesis founder Anthony Bosch, who also was accused of dealing steroids to teenagers, is serving a three-year prison sentence.

To some professional sports officials, these scandals have rendered the term “anti-aging” synonymous with “place to buy banned drugs.”

“As soon as I hear ‘anti-aging,’ I think ‘HGH,’ ” said one high-level MLB team executive who spoke on the condition of anonymity. The executive said he would be concerned if he learned any of his players visited anti-aging clinics.

Don Catlin, a UCLA anti-doping scientist and one of the founders of modern sports drug-testing, echoed the sentiment.

“For me, [athletes visiting anti-aging clinics] would mean only one thing: Someone was trying to get human growth hormone,” Catlin said.

Manning, who retired earlier this week, was unaware he was seeking permission to visit an anti-aging clinic five years ago, according to Fleischer.

In August 2011, Manning was recovering from a second neck surgery in a little more than a year, and trying to avoid needing a third. According to Fleischer, teammates suggested hyperbaric oxygen therapy, which involves lying in a chamber filled with pressurized pure oxygen. Manning’s wife, Ashley, was a patient at the Guyer Institute and knew it had a hyperbaric chamber.

“By everything Peyton knew, this facility had zero to do with anything anti-aging,” Fleischer said. “The facility had a hyperbaric chamber and was located near his home.”

Citing Ashley Manning’s medical privacy, Fleischer would not disclose why she was a patient at Guyer, only saying it was “not for anti-aging reasons.”

Last week, Fleischer arranged an interview for The Post with a former member of the Colts medical team who spoke on the condition of anonymity. The doctor corroborated Fleischer’s account.

When asked why Manning didn’t just buy a hyperbaric chamber — many athletes own the chambers, which can cost about $5,000 to $10,000 — the doctor laughed.

“Believe it or not, Peyton Manning is an incredibly frugal individual,” the doctor said. “He squeezes pennies tighter than anyone I know.”

At the clinic, Manning also tried enhanced external counterpulsation — a treatment involving inflated pressure cuffs that are supposed to increase blood flow — and some nutrient-rich intravenous solutions, the doctor said.

In the Al Jazeera documentary, Sly, who interned at the Guyer Institute, is recorded saying the clinic shipped HGH to the Mannings under Ashley’s name. Fleischer has confirmed the clinic shipped unspecified medication to Ashley Manning but said Peyton Manning never took it.

In 2007, Guyer was mentioned in a federal indictment of a Colorado pharmacist who illegally imported HGH from China. Guyer purchased HGH from this pharmacist, the indictment states, but it’s unclear whether Guyer knew the drug’s origin. Guyer was never charged with a crime.

Guyer, who earned his doctor of medicine degree from Indiana University School of Medicine, declined a request for an interview. His lawyer declined to specify whether Guyer has treated any other professional athletes.

Peyton Manning’s representative said the former quarterback was unaware that the Guyer Institute was an anti-aging clinic when he went there in 2011. (Katherine Frey/The Washington Post)
Bait and switch

From the outside, Rejuvenate You Wellness & Anti-Aging Center doesn’t look like much — it’s a squat, aqua building in a suburban Florida strip mall — but according to the company’s Facebook page, it has treated several professional athletes.

Former Nationals reliever Tyler Clippard has appeared in photos at the Bradenton clinic, and so has Packers linebacker Neal. A photo of Rejuvenate You’s “athlete wall of fame” shows a signed, framed Nationals jersey from Zimmerman.

Rejuvenate You is owned by Rucker, 46, a University of Virginia School of Medicine graduate who worked as a urologist before growing disillusioned with “big practice and monopoly insurance models,” according to his clinic’s website.

While Rejuvenate You proudly touts its athlete clients on social media, those same clients are reluctant to discuss their treatment. In addition to Zimmerman, Howard and Neal, former MLB pitcher Shaun Marcum and Clippard — both former patients — refused interview requests about Rucker.

The Phillies’ medical staff has never heard of Rucker, a spokeswoman said. Former Nationals medical director Wiemi Douoguih also said he had never heard of Rucker.

“I have no knowledge of our players going to an outside clinic, and I was never solicited by the players about going somewhere like what is being talked about,” said Douoguih, who worked for the team until this offseason.

Rucker, citing federal medical privacy laws, declined to talk about specific patients. Speaking generally, Rucker attributed his athlete client base to a friendship with the trainer Riley and word-of-mouth in the Tampa Bay area, where many current and former professional athletes live. Rucker said he offers two treatments that athletes find appealing: platelet-rich plasma therapy and ozone injection therapy.

Platelet-rich plasma therapy involves drawing a patient’s blood, spinning it in a centrifuge to separate the platelets — clotting agents in the blood — and then injecting a platelet-heavy mixture into the injured joint. Ozone therapy involves injecting a type of oxygen directly into an injured joint.

Rucker also owns a nutritional supplement company, Vitalitrek. The company sells a supplement called “Strength and Performance” that costs $250 per bottle and, according to its online description, includes insulin-like growth factor 1, a banned substance. Rucker declined to answer questions about where he gets his supplements.

“From a reputable supplement maker,” Rucker said. “They did all the hard work. I just put my label on it.”

Rucker’s clinic also advertises HCG weight loss. Human chorionic gonadotropin — a hormone produced by pregnant women — is a banned drug that helps kick-start testosterone production in men.

HCG is also purported to have fat-shedding powers. The U.S. Food and Drug Administration discourages doctors from prescribing HCG for weight loss, though, because there is no evidence it works and there have been reports linking HCG weight loss usage to blocked lung arteries, heart attacks and death.

Rucker said he doesn’t actually recommend HCG for weight loss; he just advertises it to get clients in the door and then recommends natural supplements such as his “Metabolic Enhancer,” which costs $150 per bottle.

“Haven’t you ever heard of bait and switch?” said Rucker’s lawyer, Bryan Hannan, in response to questions about why Rucker would advertise a treatment he doesn’t recommend.

Although Howard is arguably the most famous athlete Rucker has treated, there are no Rejuvenate You Facebook photos touting Howard as a patient. Rucker’s brother, Joseph Dini Rucker, posted a photo of Howard to his personal Facebook account in March 2014.

Rucker’s brother also posted an interesting video on Instagram in Oct. 2013. The video shows Sly — who two years later would be recorded without his knowledge making claims about illicit drug use by a bevy of professional athletes — giving Bino Rucker an injection.

“Dr. Rucker getting an ozone shoulder injection from our very own Dr. Sly!” the caption reads.

Bino Rucker said he has met Sly only once, a few years ago. When directed to the video of Sly injecting him, Rucker said he was unaware of the video’s existence, and he disputed the accuracy of the caption his brother wrote referring to “our very own Dr. Sly.”

Rucker said he has never worked with Sly, who has a doctor of pharmacy degree but no license.

Rucker said he met Sly through Riley, who declined an interview request for this story. In an email, Riley wrote: “I do not know the extent of Charlie Sly’s relationship with Dr. Rucker, and I do not want to speculate.”

Sly did not reply to requests to comment. Rucker’s brother Dini declined an interview request.

After weeks of refusing interview requests, Bino Rucker agreed to one last month. Rucker started the interview by saying he doubted reporters who lacked “a strong medical background” could understand what he does. Later in the 50-minute discussion, he informed reporters that because he charges an expensive hourly rate, they were “getting a great deal.”

Last week, Rucker declined a request for a follow-up interview. In the past month, several social media posts linking Rucker to athletes disappeared.

Among the posts removed, as of Thursday: the photo of Howard, the video of Sly injecting Rucker and photos of the signed jersey from Zimmerman and Rejuvenate You’s “athlete wall of fame.”

Staff writer Barry Svrluga contributed to this report.