Multi-day juice cures promising to 'cleanse the body of toxins' regularly come back into fashion. We check whether there's any solid scientific evidence behind these promises.
TL;DR — key takeaways
Juice cures, promoted as a way to 'cleanse the body of toxins', 'reset metabolism' or 'take the load off the liver', usually involve replacing regular meals for several days with fruit and vegetable juices only. The problem starts right at the level of terminology — the word 'toxins' in this context rarely refers to a specific, identified substance the cure is supposed to remove.
A critical review by Klein and Kiat, published in the Journal of Human Nutrition and Dietetics, analyzed the available research on popular detox diets, including juice cures, for actual evidence of their effectiveness in 'removing toxins' or improving liver function.
Detox diets for toxin elimination and weight management: a critical review of the evidence
Moderate evidenceKlein AV, Kiat H · Journal of Human Nutrition and Dietetics · 2015
The review found no solid clinical evidence that popular detox diets, including juice cures, actually remove defined toxins from the body or provide benefits beyond the effect of a short-term caloric deficit itself.
View studyThe liver and kidneys already do this job
Strong evidenceThe liver and kidneys are specialized organs whose daily physiological function is to metabolize and remove metabolic byproducts and foreign substances from the body — this process runs continuously, whether you drink juice or eat regular meals, as long as those organs are functioning properly.
The weight loss observed during short juice cures mainly comes from a simple caloric deficit and water loss, not from some specific 'detoxifying' action of the juices — the same effect can be achieved with a different, better-balanced way of eating with a similar caloric deficit, without losing the fiber and protein that juices are usually stripped of.
Lack of fiber and protein is a real downside, not an upside
The juicing process removes most of the fiber present in whole fruits and vegetables, which speeds up sugar absorption and can lead to sharper blood glucose swings than eating the same produce whole.
Individual 'trendy' variants of juice cures, like the celery juice popular on social media and drunk daily on an empty stomach, rely on the same marketing mechanism as general 'detoxes' — attributing a wide range of benefits to a single product (from 'cleansing the liver' to 'improving skin'), without clinical studies that actually test these specific claims in humans. Celery juice provides certain nutrients and is low in calories, but it doesn't differ fundamentally from other vegetables in this regard, and the unique 'detoxifying' properties attributed to it have no separate support in the scientific literature beyond the general evidence for the nutritional value of vegetables as such.
The mechanism driving the popularity of such trends is usually the same: a single, well-documented anecdote or influencer testimonial, repeated without critical scrutiny until it starts being perceived as an established scientific fact — even though it has never been tested in a controlled study in humans.
A few days of juice detox 'cleanses' the body of accumulated toxins.
There's no solid scientific evidence that juice cures remove any specific, defined toxins — that function is continuously performed by the liver and kidneys, regardless of the type of meals consumed.
Fresh fruit and vegetable juices can be a tasty, valuable part of a varied diet, but treating a multi-day juice cure as a way to 'detoxify' the body has no solid scientific support. If the goal is short-term weight reduction, any well-balanced caloric deficit will produce a similar effect without losing fiber and protein.
Detox marketing thrives on the vagueness of the word 'toxins' — when I ask directly what specific substance a given cure is supposed to remove and how that was measured, the answer is rarely satisfying.
dr Anna Kowalczyk, VitMode editorial team
No, fresh juices can be a valuable addition to a varied diet, but they shouldn't replace whole fruits and vegetables long-term because of the fiber lost during juicing.
Mainly from a caloric deficit and water loss, not from some specific 'detoxifying' action — the same effect can be achieved with a different, better-balanced way of eating.
The liver and kidneys continuously metabolize and remove metabolic byproducts as part of their normal physiological function — in healthy people, there's no solid evidence that a short juice cure improves this function beyond what these organs normally do.
dr Anna Kowalczyk
PhD in Molecular Biology (University of Warsaw), 8 years researching cellular aging
Anna oversees the editorial process and scientific review of every publication in the knowledge base. She previously researched autophagy and mitochondrial biology.
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Kasia W. 2 weeks ago
Very clearly explained, especially the interactions section — I hadn't seen it laid out this well anywhere else.
Marek T. a month ago
Are you planning to update this with the newest study from this year? I saw an interesting meta-analysis.
