Detox diets and juice cleanses: do they work?

Short answer

There is no evidence that they remove toxins. Body weight dropped 1.7 kg in 3 days, but nearly half came back within 2 weeks, and they did not beat simply eating the same number of calories.

Detox diets and juice cleanses: do they work?
'Juice only → flush out toxins → lose weight' — true?
Many programs claim that drinking only juice or detox drinks for a few days flushes toxins and melts weight. We checked toxin removal and weight loss separately against the research.
Is there evidence toxins come out?
Not a single randomized trial in people
A 2015 review of detox diets did not find one study that tested a commercial detox diet in people with random assignment. The few studies claiming toxins were removed had small groups and flawed methods.
But body weight did drop
7 kg in 3 days of juice
When 20 people drank only vegetable and fruit juice for 3 days (1,310 kcal a day), they lost 1.7 kg. But 2 weeks after returning to normal eating, only 0.91 kg of that loss remained. Nearly half the lost weight came back.
What leaves in the first few days is mostly water
Each 1 g of stored carbs holds 3-4 g of water
Carbohydrate stored in the body (glycogen) holds 3-4 g of water for every 1 g. Cut calories hard and this store is used first, leaving along with its water. That is why weight lost in a few days comes back fast once you eat again.
So was the lemon detox special?
A fake juice with the same calories worked too
84 people were split for 7 days into a lemon detox juice, a fake juice with the same calories, or normal meals. Body weight and body fat percentage dropped much more with both juices than with normal meals. The researchers also put the weight loss down to cutting calories.
Detox diet vs simply eating less
Eating less lost 1.7 times more
45 people spent 4 weeks on a detox diet, a regular low-calorie diet with similar calories (about 1,220 kcal a day), or their usual meals. The detox group lost 1.88 kg and the regular low-calorie group lost 3.22 kg. The detox group did not lose more body fat either.
There was a price too
Kidney failure after a green juice cleanse
1 person who did a green juice cleanse made from oxalate-rich leafy greens suffered sudden kidney damage that never recovered. A 2026 review of 10 studies on detox teas found reports of electrolyte problems, heart problems and liver injury, plus drug ingredients not listed on the label.
Summary: what leaves is calories and water, not toxins
You lose only as much as you stop eating
There was no evidence of toxin removal. 3 days of juice took off 1.7 kg, but nearly half came back in 2 weeks. A same-calorie fake juice worked too, and a detox diet did not beat a plain low-calorie diet. Think of a detox as just one way of cutting calories.