Nowadays Californians are willing to fork over as much for a mixture of fruits and vegetables as they are for a custom cocktail. More than 100 juice bars were opened in California in 2011, while numerous cafes have added juices to their menus.

Even traditional restaurants such as Porta Via in Beverly Hills, Calif., have started offering such liquid fare. At Porta Via, it’s the “green juice,” a concoction of kale, spinach, celery, cucumber and parsley, which runs a pricey $6.50 but is considerably cheaper than the $9 it costs for a 16-ounce straight lemon juice at the Beverly Hills Juice Bar in West Hollywood, Calif.

Just as they embraced the Atkins diet a decade ago, Californians are looking to the juice cleanse as the answer to weight gain and low energy. They are not cheap or easy, averaging $60 to $300 per day and lasting anywhere between three days to a month. The typical cleanse is composed of six to 10 mixed fruit and vegetable juices along with almond or soy milk, and the consumption of solid foods is discouraged.

Pressed Juicery in Brentwood, Calif., delivers juices to the client’s doorstep for $210 (three-day cleanse), $350 (five-day cleanse) or $700 (10-day cleanse). Suzanne Hall of Pressed Juicery describes the program as, "a vacation for your body. You can take a break from eating all of the junk that you would otherwise eat."

  Michelle Haloossim, a 24-year-old Los Angeles native,  is now a graduate student of Public Health at Columbia University and an avid cleanser. Haloossim has done the three-day cleanse three separate times, paying $300 for each cleanse.  "When I cleanse, I feel absolutely amazing, super energized, and clear headed,” Haloossim said. “My skin looks better, I was obviously thinner, and I woke up every day without that tired, sore feeling I usually wake up with." The one inconvenience was, "the cleanse that I do requires me to follow a regimen of no starches, dairy and caffeine for three days before and after the cleanse."

Tiffany Afshani, a 23-year-old hospitality student at Boston University, tried a bunch of cleanses. She heard about the craze while working at Vital Juice, a daily health and fitness newsletter. "I originally got the idea from my co-workers at Vital Juice Daily; I've done Blueprint, Organic Avenue, Liquiteria and Ritual Cleanse,” Ashani said. “I am a big believer in having a juice as a supplement to your daily intake to make sure of getting the necessary chloroxygen and vital green super foods."

Afshani’s favorite is also a touch more expensive: the $375 Organic Avenue three-day cleanse, which guarantees that all products are organic. "The juices can be delicious --if you don't count the green ones-- as well,” she said. “I personally also benefit from cleansing because it is my excuse to avoid drinking alcohol and eating sweets in conjunction with a detox."

So how do experts explain Shafai’s bad reaction to the cleanse? Medical practitioners are skeptical that juice and only juice is the way to bodily happiness. Nutritionist Desiree Nazarian is opposed to any sort of extreme diet and stresses that the key to health and weight loss is a balanced diet.

“People on the cleanse don't get the adequate amount of protein, carbohydrates and other essential nutrients," Nazarian said. "What people need to realize is that the body automatically cleanses itself. And the body will tell you what it is deprived of through cravings."

Dermatologist  Raphael Darvish is seeing a connection between juice cleanses and increased acne. "The high glycemic index can cause acne and has definitely been shown to cause people to be more prone to acne,”  Darvish said.

Even more alarming, Houston-based cardiologist David Filsoof says that people on the juice cleanses "have a chance of having a low blood sugar because it is a huge surge of insulin by simple sugars that are not offset by complex sugars and carbohydrates. People also run the risk of becoming hypoglycemic. If people do it more than one day or for a prolonged time, they have a higher chance of having liver complications."

Another concern, says Filsoof,  is muscle deterioration. "There is an immense muscle breakdown when you are not getting your essential amino and fatty acids. If you are trying to do the juice cleanse for weight loss it will work, but it's dangerous, and there are healthier and better ways to lose weight."

Reach reporter Candice here.