Juice cleanses are one of the more popular “treatments” that are widely promoted on social media. People believe that doing a juice cleanse is a healthy way to take care of themselves.

Of course, the scientific evidence shows that juice cleanses don’t improve your health, and they may be dangerous. It is a typical alternative medicine where there is a belief that it does something, but there is no evidence supporting its safety or effectiveness.

This post will examine the current evidence about the health impact, good or bad, of juice cleanses.

What are juice cleanses?

A juice cleanse is a type of diet that involves consuming only juices from vegetables and fruits for a short period, while abstaining from solid food, usually one to seven days. It is also known as a juice fast and is believed to flood the body with healing nourishment while flushing toxins and waste.

Proponents claim that juice cleanses can aid in liver detoxification or can help reduce gut inflammation.

None of the health claims are supported by scientific evidence.

Juice cleansing science

In reality, the majority of juice cleanses harm gut health. They can cause irregular bowel movements and even precipitate inflammatory bowel disease, a group of conditions that cause the digestive system to become inflamed (red, swollen, and sometimes painful).

The gut microbiota is disrupted due to the lack of fiber in juice cleanses. This can exacerbate or even cause inflammatory bowel disease.

According to the US National Center for Complementary and Integrative Health (I, and others, are not fans of this group, but sometimes they get it right), there is little evidence to support the use of juice cleanses for eliminating toxins from the body. In addition, some juices used in these cleanses have not been pasteurized or treated in other ways to kill harmful bacteria. They can expose individuals to E. coli, Salmonella, hepatitis A, and Cryptosporidium.

Additionally, some juices used in these cleanses are made from foods high in oxalate, such as leafy green vegetables and beets. High oxalates can lead to kidney stone formation in susceptible individuals.

In a paper published on 27 January 2025 in Nutrients, Melinda Ring, MD, Osher Center for Integrative Health, Northwestern University, Chicago, and colleagues developed a small, randomized, three-arm intervention study with 14 healthy participants.

Participants followed one of three diets — juice only, juice plus food, or plant-based food — for 3 days. Microbiota samples (stool, saliva, and inner cheek swabs) were collected at baseline, after a pre-intervention elimination diet, immediately after the juice intervention, and 14 days after consuming the diets. Gene sequencing was used to analyze the taxonomic composition of microbiota.

The juice-only group showed the most significant increase in bacteria associated with inflammation and gut permeability, as well as associated changes in the saliva and cheek microbiota, particularly in the relative abundances of proinflammatory bacterial families.

The individuals in the three-day exclusive juice cleanse exhibited shifts in their oral and gut microbiome with increases in gut taxa, which are linked to inflammation, gut permeability, and cognitive decline after juice consumption.

Admittedly, it was a small study, but “the findings suggest that short-term juice consumption may negatively affect the microbiota.”

As for “detoxing the liver,” this is a marketing myth that ignores the physiology of the liver. The liver is very capable of detoxing itself, and there are no outside forces, like a juice cleanse, that will change that.

The American Cancer Society states that “there is no scientific evidence to support claims that consuming only juices for one or more days, known as juice cleansing or juice detoxification, reduces cancer risk or provides other health benefits.”

Summary

Juice cleanses are often promoted heavily on late-night TV and on social media. They make outlandish claims, but the science is not there.

A juice cleanse is not going to detoxify your liver or body. A juice cleanse is not going to make your gut work better. A juice cleanse is not going to get rid of cancer. A juice cleanse may be dangerous to you.

Yes, eating more fruits and vegetables is an important part of a healthy diet. However, when those fruits and vegetables are turned into a juice, processing and/or storing 100% fruit juice reduces vitamins and other antioxidant contents and transforms intrinsic sugars in the whole fruit into free sugars, which have little nutritional benefit.

Juice cleanses are just another scam from alternative “medicine.”

Citations

• Mavadiya HB, Roh D, Ly A, Lu Y. Whole Fruits Versus 100% Fruit Juice: Revisiting the Evidence and Its Implications for US Healthy Dietary Recommendations. Nutr Bull. 2025 May 7. doi: 10.1111/nbu.70009. Epub ahead of print. PMID: 40341750.
• Sardaro MLS, Grote V, Baik J, Atallah M, Amato KR, Ring M. Effects of Vegetable and Fruit Juicing on Gut and Oral Microbiome Composition. Nutrients. 2025 Jan 27;17(3):458. doi: 10.3390/nu17030458. PMID: 39940316; PMCID: PMC11820471.

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