"Detox", "liver cleansing", "removal of waste" - these words sell juices, teas, herbal collections and whole courses of procedures. People who exercise, take a lot of supplements, or have had a "chemical" cycle are especially willing to offer such products. The editors checked what the promises of the detox industry are based on and what science knows about liver function.
Where did the idea of "slags" come from
The idea that "poisons" accumulate in the body, which must be removed periodically, is very old. At the beginning of the 20th century, the theory of "autointoxication" was popular, according to which rotting food in the intestines supposedly poisons the body. Medicine abandoned it a few generations ago, but the very metaphor of a "contaminated" body has proven to be extremely viable in marketing.
A characteristic feature of detox advertising is uncertainty. It is almost never mentioned exactly which "toxins" are excreted, in what quantity and with what analysis it can be checked. When journalists and scientists asked manufacturers to specify, they mostly did not receive a clear answer. Without the named substance and measurement method, the statement cannot be confirmed or denied.
A critical review by Klein and Kiat (2015) analyzed the available research on commercial detox diets. The authors concluded that there is no conclusive evidence of specific toxin elimination or sustained weight loss from such programs, and that the available studies had small sample sizes and methodological flaws.
It is important to distinguish the household and medical meaning of the word "detoxification". In clinical medicine, this is the treatment of acute poisonings, overdoses, and withdrawal states — in a hospital, with antidotes, drips, hemodialysis. This process has nothing to do with juices or teas.
How the liver actually detoxifies substances
The liver is the main biochemical "refining plant" of the body. It does not accumulate toxins like a clogged filter, but continuously converts them into compounds that can be removed with bile or urine. This process is ongoing and does not require separate "unloading" courses.
Biotransformation is traditionally divided into two phases. In the first, enzymes of the cytochrome P450 family oxidize, reduce or hydrolyze the molecule. In the second, water-soluble groups — glucuronic acid, sulfate, glutathione, and amino acids — join it. As a result, lipophilic substances become water-soluble, and the kidneys and intestines can excrete them.
In addition to the liver, kidneys, intestines, lungs and skin are involved in detoxification. A healthy system copes with everyday stress - metabolic products, drugs in therapeutic doses, moderate amounts of alcohol. Problems arise not because of "lack of cleansing", but because of damage to the liver tissue itself.
The real causes of liver damage are well known: excessive alcohol consumption, viral hepatitis, non-alcoholic (metabolically associated) fatty liver disease, paracetamol overdose, certain drugs, oral 17-alpha-alkylated anabolic steroids and, paradoxically, certain herbal and dietary supplements.
Popular detox products under the microscope
The most famous "hepatoprotector" from the shelf of a pharmacy or supplement store is milk thistle (silymarin). Silymarin has shown antioxidant properties in laboratory models, but the Cochrane Collaborative Systematic Review on Alcoholic Liver Disease and Viral Hepatitis B and C found no significant effect on mortality or complications in high-quality studies. Milk thistle is relatively safe, but it does not "cleanse" the liver.
| Product / procedure | Promise | What is known from research |
|---|---|---|
| Milk thistle (silymarin) | Restoration of liver cells | Convincing clinical effect on important outcomes not shown |
| Juice detox | Elimination of toxins, weight loss | Weight loss mainly due to water and calorie deficit; toxins not identified |
| “Liver flush” with oil and juice | Exit of "stones" | "Stones" in stools - soapy oil, not gallstones |
| Detox teas | Body cleansing | Often contains laxatives (senna) — risk of electrolyte loss |
| Essential phospholipids | Restoration of hepatocyte membranes | The evidence base is limited, not recommended as the basis of treatment in international guidelines |
The popular “liver washes” with olive oil and lemon or grapefruit juice should be mentioned separately. After them, people find greenish balls in the feces and consider them gallstones. The analysis of such formations showed that they are products of saponification of fatty acids, which are formed in the intestine from the oil consumed.
Juice detox diets can indeed produce rapid weight loss, but it's mostly water and glycogen that returns after normal eating is resumed. For a person who is training, a multi-day restriction of protein against the background of loads also means a loss of muscle tissue.
When "cleaning" can hurt
The paradox of the detox market is that some of the means for "healing the liver" can itself affect it. A review by Navarro et al. (2017) found that herbal and nutritional supplements account for an increasing proportion of drug-induced liver injury in the US, particularly diet products and non-transparent "sports" boosters.
Among the substances with the described hepatotoxic potential are green tea extract in high doses in the form of capsules, kava kava, certain multicomponent fat burners and products containing undeclared anabolic steroids. That is, a person who "treats the liver" with an unknown drug risks adding another burden to it.
- Laxative detox teas can cause dehydration and potassium disturbances.
- Starvation and prolonged monodiets impair recovery and reduce performance.
- Enemas and "bowel cleansing" have the risk of injury and disruption of the microflora.
- Belief in "cleansing" may delay seeking a doctor for true symptoms of liver disease.
The last point is probably the most important. Jaundice, dark urine, light-colored feces, itching of the skin, pain in the right hypochondrium - a reason for an urgent examination, and not for a course of herbal tea.
What really helps the liver
Science-based measures to protect the liver look much more mundane than detox programs, but they work. The guidelines of the European hepatological associations regarding fatty liver disease emphasize that the main intervention is a change in lifestyle: reduction of excess weight, physical activity and a balanced diet.
Regular training is one of the best "detox procedures" for the liver: it reduces the accumulation of fat in it even without significant weight loss. Limiting alcohol and added sugar, especially fructose from sweet drinks, reduces the burden on liver metabolism.
For people who take many supplements, the rational approach is not to add another "for the liver", but to critically review the existing ones. Choose products with a transparent composition and independent certification, do not exceed the doses indicated on the label, avoid combining several stimulants and fat burners.
Finally, the real condition of the liver is assessed by tests, not by sensations: ALT, AST, GGT, bilirubin, alkaline phosphatase, if necessary, ultrasound. It is important to remember that after intense strength training, AST and ALT can temporarily increase due to the muscles, so the doctor should be informed about the load before donating blood.
Editorial conclusions
A healthy liver does not need a “cleanse”: it detoxifies and removes substances continuously, and no detox program has been shown to be able to speed up this process.
Popular remedies from milk thistle to "flushes" do not have convincing clinical evidence, and some detox products and opaque supplements can themselves be hepatotoxic.
The best liver protection is moderation in alcohol consumption, weight control, physical activity, caution with supplements, and regular checkups.
The editors also recommend reading our materials on liver tests in athletes, hepatotoxicity of oral steroids and the quality of sports supplements.
List of used literature
- Klein AV, Kiat H. Detox diets for toxin elimination and weight management: a critical review of the evidence. J Hum Nutr Diet. 2015;28(6):675â686.
- Rambaldi A, Jacobs BP, Gluud C. Milk thistle for alcoholic and/or hepatitis B or C virus liver diseases. Cochrane Database Syst Rev. 2007;(4):CD003620.
- Navarro VJ, Khan I, Björnsson E, et al. Liver injury from herbal and dietary supplements. Hepatology. 2017;65(1):363â373.
- European Association for the Study of the Liver (EASL), EASD, EASO. EASL-EASD-EASO Clinical Practice Guidelines for the management of non-alcoholic fatty liver disease. J Hepatol. 2016;64(6):1388â1402.
- LiverTox: Clinical and Research Information on Drug-Induced Liver Injury. Bethesda (MD): National Institute of Diabetes and Digestive and Kidney Diseases.
- Pope HG Jr, Wood RI, Rogol A, et al. Adverse health consequences of performance-enhancing drugs: an Endocrine Society scientific statement. Endocr Rev. 2014;35(3):341â375.
