Juice fasting, also known as juice cleansing, is a fad diet in which a person consumes only fruit and vegetable juices while otherwise abstaining from food consumption. It is used for a detoxification alternative medicine treatment and is often part of detox diets.
This fad is promoted with implausible and unevidenced claims for its health benefits. 
Juice fasting is closely associated with detox.
Catherine Collins, Chief Dietician of St George's Hospital Medical School in London, England, states that "The concept of ‘detox’ is a marketing myth rather than a physiological entity. The idea that an avalanche of vitamins, minerals, and laxatives taken over a 2 to 7 day period can have a long-lasting benefit for the body is also a marketing myth." Detox diets, depending on the type and duration, are viewed as potentially dangerous and can cause various health problems including muscle loss and an unhealthy re-gaining of fat after the detox ends.
Juice mixes containing grapefruit juice may also adversely interact with certain prescription drugs.
- Valiant, Melissa (27 May 2015). "Do Juice Cleanses Work? 10 Truths About The Fad". Huffington Post.
- Debunking detox Archived 2014-04-18 at the Wayback Machine.
- The Truth About Detox Diets
- "Grapefruit Juice and Some Oral Drugs: a Bitter Combination". Nutrition Bytes (UCLA). 1999. Retrieved 2009-05-04.