DÜSSELDORF, Germany — The medical treatment for Lindsey Berg's arthritic left knee has not been approved by the Food and Drug Administration, and neither her professional volleyball team in Italy nor the United States Olympic team would help with the cost. But for Berg, a gold medal hopeful, the chance to dull the chronic pain was worth the money, and the risk.
So between the end of her professional season and the start of Olympic practices in California, Berg stopped at the office of Dr. Peter Wehling on the bank of the Rhine River. "I've been struggling with knee pain for the last four years and just continuing to play on it," said Berg, 31, who had tried surgery and cortisone injections to little avail.
After examining her, Wehling and his team drew syringes of her blood. First they incubated it. Then they spun it in a centrifuge. The blood cells produce proteins that reduce inflammation and stimulate cellular growth; sometimes additional anti-inflammatory proteins are added to the solution. Finally, Wehling injected the orange serum into Berg's knee.
The price came to 6,000 euros, or about $7,400, out of her own pocket, but with the Olympics in London coming up, any treatment that might make her knee better was worth it. "It's your body and your money because they're not paying for it," she said with cheerful resignation, on the fourth day of her treatment.
Wehling's practice has become almost a pilgrimage site for athletes trying to prolong careers that have tested the limits of their bodies. It has also been the subject of no small amount of speculation after word leaked last year that the Los Angeles Lakers star Kobe Bryant had flown to Düsseldorf for the treatments. Alex Rodriguez of the Yankees traveled there as well. After the N.B.A. season ended, Lakers center Andrew Bynum, Bryant's teammate, said he, too, would try it.
Commentators wanted to know if there was something fishy that required Bryant to go abroad for medical treatment. As his scoring average increased and the aging star seemed rejuvenated, the interest in the trips to Germany and the unusual treatment grew.
To answer the most common questions: Wehling's practice is not at the end of a dark alley but in a modern building south of the city's old town; it is brightly rather than dimly lighted, with orange floors and a water cooler in the waiting room; and Wehling seems more like a true believer in his Regenokine therapy than a snake-oil salesman. He said he was careful not to use any substances banned by athletic governing bodies.
Biologic medicine is a rapidly growing field. Wehling's Regenokine treatment might sound similar to another blood-spinning treatment, known as platelet-rich plasma, or P.R.P., that has gained popularity in the United States in recent years. In that procedure, the goal is to produce a high concentration of platelet cells, which are believed to speed the healing process. Wehling said his treatment differed from P.R.P. because he heats the blood before it is spun to increase the concentration of anti-inflammatory proteins, rather than the platelets, in his cell-free solution.
The idea is not just to focus on mechanical problems in the joints or lower back but to treat inflammation as a cause of tissue damage as well as a symptom.
"The potential of biology to treat orthopedic problems is high because it has only been developed a little," Wehling said in an interview.
"It has to be embedded in a good concept more broadly," he added, emphasizing that sleep, diet and conditioning are among the important components to go with the injections. "There's no such thing as the one therapy that fixes everything."
On a recent morning he treated not only Berg but also a basketball player, a golfer, a Hollywood executive and a former martial artist.
"The results were incredible," Vijay Singh, the world's former No. 1 golfer and a patient of Wehling's, said in a telephone interview. "It's like somebody just put oil all over your body. It lubes you up, and you're able to move more freely, especially pain free."
The question is how effective the treatment will prove in the long run.
Dr. Freddie Fu, a professor of orthopedic surgery at the University of Pittsburgh, has been critical of many such treatments, including P.R.P. He was slightly more optimistic about Wehling's approach.
"The gimmick is, it's your own body, it must be safe," Fu said. "There has been some impressive research done already, and there is a good scientific fundament to do more research.
"However, before the F.D.A. approves, more high-quality independent trials have to be done in order to prove the effectiveness."
Recent patients speak glowingly of the doctor as well as his therapy.
"When you come here and are skeptical and all your pain disappears, it makes you all the more devoted to the science of it," said Tim Shaheen, from Los Angeles. "What about people on assembly lines with terrible knees and terrible backs? This would be a lifesaver for that in quality of life."
The therapy generally lasts five days, starting with an evaluation and, if the patient decides to go ahead, drawing the blood.
"As much blood as they took the first day, I didn't think I'd have any left," said Wes Short Jr., a professional golfer from Austin, Tex. It was his first trip to Germany, he said, indeed his first to a non-English-speaking country, and he still marveled at the fact that most of the taxis were Mercedeses.
Short lay on his stomach, his green short-sleeve shirt hiked up. Wehling had just injected several syringes of serum into the small of his back. Afterward the doctor left half a dozen acupuncture needles quivering in Short's back.
The fact that Wehling had treated Pope John Paul II made a strong impression on Short. "I'm sure he doesn't trust just anybody," said Short, who hoped to start playing again if the treatment worked.
Wehling's book "The End of Pain" begins with a "Da Vinci Code"-style trip to the Vatican and, escorted by the Swiss Guard, into John Paul II's private chamber. "The hard marble floors echoed with emptiness," Wehling wrote. But why, he asked, had the pope chosen his treatment? "Because your treatment comes from God," the pope said, referring, Wehling wrote, to the fact that it comes from the body.
Wehling comes from an old Rhineland family. His great-uncle was the archbishop of Cologne, and as a boy he met the future Pope Benedict XVI, Joseph Ratzinger. A father of two, Wehling plays keyboard in two bands, one jazz and one blues, giving off the vibe of a goofy-cool uncle, a little too enthusiastic to be completely hip.
"He's very honest," said Jeff Kwatinetz, president of the production company Prospect Park, who traveled from Los Angeles to receive the treatment on both shoulders. He was as impressed with Wehling's bedside manner as the mobility he had regained in his joints. "He hopes it can work, thinks it can work, but he's not making any promises."
Wehling manages to buzz through his clinic at high speed yet somehow make each patient feel as though he has all the time in the world for him or her. When talking to Wehling, the term "exciting," is often used — the research, the possibilities. There are two offices, one in New York and one in Los Angeles, licensed to provide a similar treatment, though they cannot advertise because of the lack of F.D.A. approval.
"When you're one of the progenitors of a new way of thinking, you really want to have it thrive," said Chris Evans, the Müller professor of orthopedic surgery at Harvard Medical School, who wrote the introduction to Wehling's book and serves unpaid on the supervisory board of the company Wehling founded. He is developing an idea that came to him when he was a young resident in neurophysiology and orthopedics, Dr. Evans said, and "now that he's middle-aged he wants to see that it's out there and that it works."