Detox diets: what dietitians want people to know

By the DieticiansWorldwide.com editorial team · 17 October 2026 · Public health & global nutrition

What people mean by a detox diet

"Detox" is a marketing word, not a medical one. In hospitals, detoxification means treating poisoning, drug overdose or alcohol withdrawal, or using chelation drugs to remove heavy metals in specific serious cases. The detox diets sold online and in shops are something else entirely: short programmes that promise to flush out unnamed "toxins", reset your metabolism, clear your skin and help you lose weight.

The US National Center for Complementary and Integrative Health (NCCIH) lists the approaches these programmes use: fasting, drinking only juices or similar drinks, eating only certain foods, taking supplements or herbs, cleansing the colon with enemas, laxatives or colonic irrigation, cutting environmental exposures and using saunas (NCCIH, "Detoxes" and "Cleanses"). Most commercial plans combine several of these and last from a day to a few weeks.

The British Dietetic Association (BDA) is blunt about the underlying idea. Its food fact sheet calls it "nonsense" and explains that, unless you have a serious medical condition, your body already has its own system for breaking down and removing waste (BDA, detox diets). Products such as detox teas, it notes, often work by acting as a laxative.

Do detox diets work?

It depends what you mean by "work", and that is the trick the marketing relies on.

For removing toxins

Almost no research tests whether detox products remove anything. The most cited review, by Klein and Kiat in the BDA's own Journal of Human Nutrition and Dietetics, found that "very little clinical evidence" supports these diets, that the handful of positive human studies were "hampered by flawed methodologies and small sample sizes", and that, to the authors' knowledge, no randomised controlled trials had tested commercial detox diets in humans (Klein and Kiat, 2015).

A basic problem is that products rarely name the toxin they claim to remove, or measure it before and after. Without that, "detoxifying" is a claim that cannot be tested and so cannot fail. If a toxin were genuinely building up in your body, the right response would be medical investigation, not a tea.

For weight loss

People do often weigh less after a cleanse. That is because a juice-only or very restricted plan supplies far fewer calories than usual, and because cutting carbohydrate and salt releases stored glycogen and water. A 2017 review of popular weight-loss strategies concluded that juicing and detox diets "tend to work because they lead to extremely low caloric intake for short periods of time" but "tend to lead to weight gain once a normal diet is resumed" (Obert and colleagues, Current Gastroenterology Reports 2017). NCCIH adds that there have been no studies on the long-term effects of detox programmes.

If your real goal is weight loss, the honest starting point is how much energy you need. Our calorie calculator gives you a realistic daily estimate to plan from, without starving for three days and rebounding for the next three.

For feeling better

Many people report more energy and better skin during a detox. The BDA points out why: a detox week often coincides with drinking less alcohol, cutting caffeine and sugary snacks, sleeping more and eating more fruit and vegetables. Those changes help, and they do not need a branded programme. The product gets the credit for changes you made yourself.

How the body detoxes naturally

Your body runs a detox system around the clock, and it does not need help from a powder.

• Liver. The liver chemically converts alcohol, medicines, hormones and many other compounds into forms that can be excreted in bile or urine.
• Kidneys. Each of your two kidneys contains about a million filtering units called nephrons, which remove wastes and extra fluid from the blood to make urine, while keeping the balance of water, salts and minerals steady (US National Institute of Diabetes and Digestive and Kidney Diseases).
• Gut. The intestines remove waste in stool, and the gut lining and its bacteria act as a barrier and a processing plant.
• Lungs and skin. The lungs breathe out carbon dioxide and some volatile compounds; skin is a barrier more than an exit route, and sweating in a sauna mainly loses water and salt.

These organs work well when you are healthy, and no juice makes them work faster. When they are diseased, the problem needs a doctor, and detox products can make it worse.

What genuinely supports these organs

There is nothing glamorous here, but the evidence is solid:

1. Drink less alcohol. It is the single biggest workload you put on your liver.
2. Eat enough fibre. Fibre keeps the bowel moving and feeds gut bacteria. Our high-fibre foods list shows easy ways to add it.
3. Stay hydrated, but do not overdo it. The BDA warns that drinking too much water can be as dangerous as not drinking enough.
4. Keep a healthy weight to lower the risk of fatty liver disease.
5. Do not smoke, and be careful with supplements and over-the-counter painkillers, which the liver also has to process.
6. Eat a varied, mostly plant-rich diet with enough protein. Patterns such as the Mediterranean diet have far more evidence behind them than any cleanse.

Are juice cleanses safe?

For most healthy adults, a single day of juice is unlikely to cause serious harm. Longer or repeated juice fasts carry real risks, and some people should not try them at all.

Unpasteurised juice

NCCIH warns that juices which have not been pasteurised or otherwise treated can carry harmful bacteria, and that illness can be serious in children, older people and people with weakened immune systems. Freshly pressed juice from a café or a home juicer falls into this group.

Oxalate and kidney damage

Spinach, beetroot and other leafy greens are high in oxalate. In normal portions with meals this is not a concern for most people, but concentrated juice is different. One published case describes a 68-year-old man with normal kidney function who started a daily juice regime high in spinach, with an estimated oxalate intake of about 1,500 mg a day, around ten times a typical diet. He developed acute oxalate nephropathy and, a year later, still needed dialysis (Chaudhari and colleagues, Case Reports in Nephrology 2022). A single case cannot tell you how common this is, but it shows the harm is not theoretical. NCCIH advises people prone to kidney stones to limit high-oxalate foods.

Blood sugar and medicines

Fruit juice delivers sugar without the fibre of whole fruit, and juice-only plans provide very little protein. If you have diabetes, a juice fast can cause both highs and lows, especially if you take insulin or tablets that lower blood sugar. NCCIH advises people with diabetes to follow the eating plan agreed with their healthcare team and to consult them before making major changes to how they eat. If you take any regular medicine, ask your pharmacist before a drastic change in diet.

Electrolytes

NCCIH warns that drinking large quantities of water and herbal tea while not eating for days in a row could lead to dangerous electrolyte imbalances. Older adults, people with heart or kidney disease and people taking diuretics are most at risk.

"Liver detox" supplements and the problem with laxatives

Liver supplements

Milk thistle is the herb most often sold as a liver cleanser. NCCIH's review of the research says clinical trials for liver diseases, including alcohol-related and fatty liver disease, have been "conflicting or too limited to allow conclusions to be reached", and that two NCCIH-funded trials of the extract silymarin did not show benefit (NCCIH, milk thistle). It also notes concerns about the quality of milk thistle products, some of which contained different amounts of the active compound from the label or were contaminated.

The bigger concern is that supplements can damage the liver they claim to clean. A research symposium run by the American Association for the Study of Liver Diseases and the US National Institutes of Health reported that herbal and dietary supplements account for 20% of cases of liver toxicity in the United States, and that most cases involve multi-ingredient products where the harmful ingredient is often unknown (Navarro and colleagues, Hepatology 2017). Many "liver detox" blends are exactly this kind of product. If you are thinking of taking one, our guide to the supplements industry explains how these products are regulated.

Laxative teas and colon cleanses

Many detox teas contain senna or other stimulant laxatives. They make you lose water and stool, which shows on the scales for a day, but they do not remove fat or calories that have already been absorbed. The NHS warns that laxatives used too often or for too long can cause dehydration, a bowel blockage and low potassium in the blood, which can lead to heart rhythm problems, and advises people buying laxatives without a prescription not to take them for longer than seven days (NHS, laxatives).

NCCIH also notes that the FDA and the US Federal Trade Commission have taken action against several companies selling detox and cleansing products, because products contained hidden ingredients, made false claims to treat serious diseases, or, for colon-cleansing devices, were marketed for unapproved uses.

Social media trends versus trial evidence

Detox content spreads because it is visual, quick and hopeful: a fridge of coloured bottles, a before-and-after photo, a promise of results by Monday. The evidence behind it is the opposite: almost no trials, no named toxins and no long-term follow-up.

A few checks help you judge any detox claim you see:

• Which toxin, and how was it measured? If the post cannot say, it is not a scientific claim.
• Who is selling what? Many detox posts are adverts for a tea, powder or programme, sometimes undisclosed.
• Is the "evidence" a testimonial? Personal stories describe experiences, not causes, and you rarely hear from people who felt ill or regained weight.
• Does it promise a lot from a little? Real changes to health take months, not three days.

The same habits of scepticism work for other diet trends. Our review of paleo, keto and carnivore diets looks at how the trial evidence compares with the online claims, and our guide to nutrition misinformation explains how to spot unreliable advice more generally.

Restrictive diets and disordered eating

Detox culture borrows the language of purity and guilt: "clean" foods, "toxic" foods, "undoing" a weekend. For most people this is just irritating. For some, it can feed a pattern of restriction followed by overeating, followed by another cleanse, which looks very like a binge–purge cycle.

Be cautious if you notice that you:

• feel you have to "make up" for eating with a cleanse or a fast;
• use detox teas or laxatives regularly;
• feel anxious or guilty when you eat foods outside a strict list;
• avoid meals with other people so you can stick to a plan;
• find your list of acceptable foods is getting shorter.

People with a current or past eating disorder, pregnant or breastfeeding women, children and teenagers, people with diabetes, and anyone with kidney, liver or heart disease should avoid detox programmes unless their own clinician has advised otherwise.

What actually helps after a period of overindulgence

The urge to detox often follows a holiday, a celebration season or a stressful stretch of eating on the run. A gentler reset works better, and it is something a dietitian would recommend:

1. Go back to regular meals. Three meals and planned snacks steady appetite better than skipping.
2. Build the plate around vegetables and fruit, with a portion of protein and some whole grains. Our free healthy eating check shows how your current day compares with an evidence-based pattern.
3. Take a few alcohol-free days and drink water as your main drink.
4. Add fibre and fermented foods if you tolerate them; our guide to probiotics explains what the evidence does and does not show for gut health.
5. Move most days, even if it is just walking.
6. Sleep. Many of the benefits people credit to detoxing come from better sleep.

If you are drawn to a more structured eating pattern for longer-term health, the anti-inflammatory diet and Mediterranean eating are better-studied options. It also helps to know what current national guidance looks like; our explainer on the new food pyramid covers the latest US advice.

When to see a professional

See your GP first if you are considering a cleanse because of symptoms such as tiredness, bloating, skin problems or changes in bowel habit. These have many causes, some of which need testing, and a detox can mask them for a while.

A registered dietitian can help if you want to lose weight, manage a condition such as diabetes or irritable bowel syndrome, or break a cycle of dieting and overeating. In the UK, "dietitian" is a protected title and "nutritionist" is not, so it is worth checking who you are taking advice from; our explainer on the difference between a dietitian and a nutritionist shows what to look for. For advice on your own situation, you can book a session with a registered professional.

Find the right nutrition professional