Henri Chenot Spa at Palace Merano
Merano Bolzano, Italy; palace.it

Seated in the foothills of the Dolomites, the spa follows the dogma of Chinese-medicine guru Henri Chenot, which focuses on cleansing the gut (using abdominal massages and colon hydrotherapy) and preserving youth (via skin-perfecting lasers). No caffeine, alcohol, fat, or sugar is allowed.
Most Extreme Treatment: Chelation Therapy
Though this technique is typically used to treat metal (e.g., mercury) poisoning, those aiming to rid themselves of toxins receive a series of IVs containing ethylene diamine tetraacetic acid (EDTA). The chemical binds to offending metals and, in theory, takes them with it during urination. Some practitioners claim that it can treat heart disease and cancer as well as improve eyesight and hearing.
Does It Work? Because it has the potential for toxic side effects (kidney disease, irregular heartbeat), most doctors don't recommend it for recreational use.
Luxury Factor: Located in a palatial 19th-century villa, the spa boasts saunas, Turkish baths, and run-of-the-mill retreat fare like seaweed and mud body wraps.
Star Sightings: Soccer icons Cristiano Ronaldo and Zinedine Zidane, Elle Macpherson, Valentino, Princess Caroline.
Cost: From $4,335 for a six-day program.

• • •

The Farm at San Benito
Lipa, Philippines; thefarmatsanbenito.com

This 118-acre organic coconut plantation's "healing sanctuary" is the setting for spa therapies, yoga, and candlelit swims in infinity pools. Guests partake of magnetic clay foot baths (to remove "radiation" from excessive phone use) and brain biofeedback scans (to measure the "energy levels" of organs, cells, and tissues) and dine in the spa's vegan restaurant.
Most Extreme Treatment: Rectal Infusion Therapy
Four to eight ounces of wheatgrass or aloe vera (used to coat and protect digestive mucus) is administered via a rubber catheter. The goal? To nourish and heal the large intestine.
Does It Work? The "light" feeling patients say they have afterward can be addicting, but there's scant evidence the procedure improves health. Most doctors agree that the colon cleanses itself just fine on its own.
Luxury Factor: The upscale tree-house-like villas have glass-walled living rooms for panoramic views of the jungle and Mount Malarayat. When guests are feeling more contemplative, they can head to one of six private meditation pavilions.
Star Sightings: Coldplay's Guy Berryman, Woody Harrelson, assorted fashion- and music-industry insiders.
Cost: From $2,860 for a five-day program.

• • •

Ananda in the Himalayas
Uttaranchal, India; anandaspa.com

Burrowed in the Himalayan foothills alongside the Ganges River, the 24,000-square-foot facility uses Ayurvedic and yogic philosophies—mixed with modern technology. Visitors stay a minimum of three nights to sample more than 80 treatments, like ear candling, aromatherapy, and rose-quartz facials.
Most Extreme Treatment: Kunjal Kriya
Also known as stomach washing, the morning yogic cleansing ritual consists of chugging four to six cups of salt water until you throw up, expelling mucus and other undigested food remnants from the bottom of your stomach. Allegedly this improves digestion.
Does It Work? You're better off starting the day with a relaxing massage. There's no scientific evidence that vomiting first thing aids in the movement of food through the intestines.
Luxury Factor: The resort is located in the former palace of a maharaja (Sanskrit for "high king"). Villas come with a private pool and butler service.
Star Sightings: Jeremy Piven, Bill Gates, Prince Charles.
Cost: From $3,780 a week.

• • •

Sha Wellness Clinic
Alicante, Spain; shawellnessclinic.com

Tucked into a hillside on Spain's Costa Blanca, the 93-room clinic serves a macrobiotic diet (vegetables, whole grains, fish) and mixes Eastern and Western treatments (Reiki in the morning; a visit to the sleep-recovery unit later). The combination is intended to tackle stress and rid the body of energy-zapping inflammation.
Most Extreme Treatment: Ozone Therapy
A pint of blood is withdrawn from the body, mixed with ozone gas and medical oxygen, then reinjected into your veins for an energy and immunity boost.
Does It Work? Patients say they feel rejuvenated post-treatment, but there's no scientific proof (the jury's out on proponents' claims that it can treat cancer and heart disease), and there are safety concerns. If the levels of gases administered are not monitored carefully, it could be toxic—even fatal.
Luxury Factor: Exudes an affluent New Age vibe. When you're not sampling the spa menu, there's yoga, cooking classes, and nude sunbathing on private terraces.
Star Sightings: Bruce Willis, Simon Cowell, Donna Karan, Naomi Campbell, as well as foreign royals and dignitaries.
Cost: From $3,200 a week.

• • •

Viva Mayr
Pörtschach, Austria; viva-mayr.com

This lakefront clinic in the mountainous Southern Carinthia region dictates that patients adhere to the Mayr Cure, a century-old strict digestive-cleansing plan. Two- and three-week stays are filled with medical testing, salt-infused drinks that encourage "toileting," and vitamin IVs. Reeducating the mouth is a priority: Guests nosh on stale spelt bread to encourage more chewing—50 times, to be precise.
Most Extreme Treatment: Bloodletting
The ancient practice of drawing blood (approximately 500 milliliters with a syringe—no leeches involved) is believed to improve circulation and lower blood pressure, which boosts the detoxification process.
Does It Work? A recent study found that just two sessions of bloodletting were enough to lower blood pressure for six weeks and help keep blood-sugar levels in check.
Luxury Factor: Think no-frills detox; deep-tissue massages and sandalwood-scented baths are as hedonistic as it gets in this rather sterile setup.
Star Sightings: Lanvin's Alber Elbaz, Hollywood A-listers, Russian oligarchs. Reportedly, Russia's first lady, Lyudmila Putin, is a repeat patient as well.
Cost: From $3,800 a week.