Do Detoxes Work? The Science Behind Cleanses, Toxins & Juice Fasts
Do Detoxes Work? The Science Behind Cleanses, Toxins & Juice Fasts
Do detoxes work? Do you need a juice cleanse to "reset" your body? Is your liver full of toxins that need flushing? Short answer: no, no, and absolutely not.
This week Zoë and Kylee debunk the detox industry, juice cleanses, detox teas, foot pads, coffee enemas, the Master Cleanse, and everything in between. We cover how your liver actually detoxifies (500+ functions, two-phase enzyme system), why your kidneys filter 200 quarts of blood daily without any help from celery juice, and what systematic reviews conclude: there's almost no clinical evidence that detox diets do anything.
We also dig into the history, from ancient Greek bloodletting to George Washington's death to John Harvey Kellogg's yogurt enemas, and the psychology of why we fall for purity narratives. Plus: why athletes are especially vulnerable, the connection between "clean eating" and orthorexia, documented harms (kidney failure, electrolyte imbalances, and yes, rectal perforations), and 8 red flags for spotting detox scams.
96 facts checked. 17 sources cited. 0 toxins removed.
Do juice cleanses actually work? Do you need a detox to "reset" your body? Is your liver full of toxins that need flushing? Short answer: no, no, and absolutely not. In this episode, Zoë and Kylee debunk the detox industry—juice cleanses, detox teas, foot pads, coffee enemas, the Master Cleanse, and everything in between. They cover how your liver actually detoxifies (500+ functions, two-phase enzyme system), why your kidneys filter 200 quarts of blood daily without any help from celery juice, and what systematic reviews conclude: there's almost no clinical evidence that detox diets do anything.
What Is a Detox? (And What Even Is a Toxin?)
ZOË: Welcome to Your Diet Sucks, the podcast that detoxes your brain, not your colon.
KYLEE: When we say detox, what are we actually talking about?
ZOË: I want to separate us from the idea of a medical detox from alcohol and drugs. That's real life-saving medicine with medical supervision. What we're talking about today is detox in the wellness term. We're talking juice cleanses, colon hydrotherapy, detox teas, charcoal everything, foot pads that turn brown, celery juice, lemon water fasts, master cleanse, liver flushes, activated charcoal lattes. And the core claim here is that these mysterious toxins accumulate and the body alone can't handle them, and you need this external intervention in order to survive.
ZOË: Thought experiment: ask any detox company to name one specific toxin their product removes. It's like saying that your car has "problems" but not specifying if it just needs gas.
KYLEE: What even is a toxin?
ZOË: In actual toxicology, a toxin is a poisonous substance produced by living organisms—like snake venom, botulinum, ricin. A toxic substance could be any chemical that can harm you at certain doses, including both natural and synthetic substances. A key principle of toxicology is "the dose makes the poison" from Paracelsus. Water can kill you if you drink too much—hyponatremia. Marathon runners have died from this. Even oxygen is technically toxic at high enough concentrations.
The History of Detoxes: From Bloodletting to Juice Cleanses
KYLEE: Have people always been obsessed with purification?
ZOË: This is ancient as hell. In 2000 BCE, there's documentation on Egyptian medical papyruses where Egyptians believed in enemas to prevent food from rotting inside them. By Vedic tradition, there was the pancha karma—a five-step detox where you would drink ghee, engage in therapeutic vomiting, enemas, and bloodletting with leeches.
ZOË: Back in ancient Greece around 400 BCE, with the four humors theory—blood, phlegm, yellow bile, and black bile—health was believed to be defined by a balance of all of these humors. Any illness was an imbalance. The solution? Pick one of those fluids and get it out of you. That's why so many treatments involved bloodletting, induced vomiting, laxatives—sometimes all three in one appointment.
ZOË: In the late 1800s to early 1900s, there was this new terrible theory called auto-intoxication—the idea that your intestines are basically a cesspool poisoning you from within. This led to people surgically removing perfectly healthy colons, having daily laxative routines, or extreme enema protocols.
ZOË: Friend of the show, John Harvey Kellogg—the Cornflakes anti-masturbation guy who ran the Battle Creek Sanitarium—used to prescribe yogurt enemas and 15-quart water enemas to his patients. He was also into eugenics. The amount of diet advocates on this show that are also super into eugenics should lead people to question everything that underpins our desire to control people and bodies.
How Your Body Actually Detoxifies (For Free)
The Liver: Your Body's Detox MVP
ZOË: Your liver is doing an insane amount of work. It performs over 500 distinct functions, it processes virtually every substance you consume, and it has a two-phase detoxification system. In phase one, enzymes called cytochrome P450s modify toxins, often making them more water-soluble. In phase two, conjugation attaches molecules to toxins, making them easier to excrete.
The Kidneys: Filtering 200 Quarts of Blood Daily
ZOË: Your kidneys filter 200 quarts of blood every single day—that's like 50 gallons. Your entire blood volume gets filtered about 40 times daily. It's a constant cleaning cycle. They produce about two quarts of urine daily containing urea from protein metabolism, creatinine from muscle, excess minerals, and metabolic waste. They also help regulate blood pressure, electrolyte balance, red blood cell production, and acid-base balance.
KYLEE: So you don't need to be drinking alkaline water—your kidneys do that.
Other Detox Systems
ZOË: Lungs expel CO2 and some volatile organic compounds with every single breath—about 20,000 breaths daily. Skin eliminates small amounts of waste through sweat, but this is a really minor route—like 1% of detox. The idea that saunas can remove tons of toxins is not supported. When you analyze sweat, it's mostly water, salt, and trace minerals.
ZOË: Your gut bacteria literally eat some toxins and break them down—it's a free biological remediation system. And your lymphatic system moves fluid, waste products, and immune cells throughout the body. Unlike the heart, it doesn't have a pump—it moves via muscle contractions. Just standing up and sitting down is enough to help lymph circulate.
What Does the Research Say About Detox Products?
ZOË: A 2015 comprehensive review in the Journal of Human Nutrition and Dietetics found almost no clinical evidence supporting detox diets. Some studies showed tiny, potentially statistically significant benefits, but they were plagued by flawed methodologies—tiny sample sizes, no controls.
KYLEE: A lot of the detox products have higher levels of milk thistle, and people don't realize that using that for a longer period of time could cause liver damage. You're trying to support detox, but then you're causing harm to the organ that detoxes.
What About Weight Loss Claims?
ZOË: Science shows that if you don't eat food, you might lose weight. Shocking. A 2015 study on 84 women who did a lemon detox diet found they all lost weight—but so did a control group on an equivalent low-calorie placebo diet. Weight loss comes from severe caloric restriction, not detoxification.
ZOË: Multiple studies show that weight loss from juice cleanses is almost never sustained. Almost everyone regains all of that weight when they return to normal eating, if not more, because of binge-restrict cycles.
Are Detoxes Harmful? Documented Dangers
ZOË: There are extensive physical dangers documented in medical literature:
- Kidney failure linked to juice cleanses from oxalate overload from green juices
- Rectal burns and perforations from coffee enemas
- Electrolyte imbalances that can cause dangerous cardiac arrhythmias, which can be fatal
- Severe nutritional deficiencies from prolonged restriction
- Muscle loss from inadequate protein—the body literally starts to cannibalize muscle tissue
- Disrupted gut microbiome because colonics and aggressive laxatives can cause inflammation, infection, and dysbiosis
ZOË: Medical literature has documented deaths from aggressive detox regimens. Not just George Washington and Mozart.
8 Red Flags for Spotting Detox Scams
ZOË: Here are red flags to know if you're being scammed:
1. Using the word "toxin" without defining which specific chemicals. Legitimate medical treatment for these things will name the problem. Chelation therapy for lead poisoning, not just "toxins." If someone can't name it, they can't remove it.
2. Anything that claims to cleanse, reset, or reboot organs. Your organs are not computers. Your biological systems self-regulate constantly. This marketing language is designed to sound medical without making falsifiable claims.
3. Before and after photos or promises of dramatic changes in days. These images show water weight loss, better lighting, flexing versus being relaxed, different posture. Not actual toxin removal.
4. Testimonials instead of peer-reviewed research. "I lost XYZ pounds and I feel amazing" is not evidence. Legitimate medical products cite studies from randomized controlled trials published in JAMA. If the only evidence is Cheryl on Instagram, that's a scam.
5. Anything sold through MLM or by fitness influencers on commission. Your gym buddy is not selling that thing because it works—they're selling it because they get a cut of the profits. Influencers selling things based on their image are selling genetics and access to resources, not a $12 tea.
6. Claims that a product "supports," "promotes," or "helps with" detoxification. These are weasel words designed to avoid FDA regulation while implying medical benefits. You can't legally claim to detoxify without evidence, so they say "supports detoxification." It's a linguistic loophole. It means nothing.
7. It's expensive and you have to keep buying it. Real medical treatment has an endpoint. Detox products require monthly subscriptions, repeated cleanses, maintenance doses—not because biological systems depend on it, but because their business model depends on recurring revenue. If you're detoxing every month forever, maybe the products just don't work.
8. It makes you feel like shit during the cleanse. Headaches, fatigue, nausea, dizziness, brain fog—products will say "that's how you know it's working." No. You are ill. You're starving yourself. Those are symptoms of malnutrition. Your body doesn't heal by making you feel worse.
What Actually Supports Your Body's Natural Detox Systems
KYLEE: Eat some fruits and veggies and fiber! I usually recommend six one-cup servings of fruit and/or vegetables a day.
ZOË: Something funny about juice cleanses: they remove fiber, which is extremely helpful for digestion and removing waste from the body. If you remove fiber from fruits and vegetables, you're robbing them of a vital nutrient that would actually make it easier for your body to dispose of waste.
What actually works:
- Stay hydrated—your kidneys need adequate water to filter waste
- Eat a balanced diet with plenty of fiber-rich vegetables
- Avoid unnecessary medications and supplements (they all go through your liver)
- Regular exercise supports liver health and metabolic function
- Don't smoke—tobacco introduces actual toxic chemicals
- Get adequate sleep—the body does most repair work during sleep
- Manage stress—chronic stress elevates cortisol, which impairs immune function
The Bottom Line
ZOË: Your body is already equipped to handle normal environmental exposures, and the scientific consensus is clear: detox products are, at best, unnecessary, and at worst, harmful. This entire industry thrives on manufacturing problems and then selling solutions to problems that don't exist.
References
Peer-Reviewed Research
Klein, A. V., & Kiat, H. (2015). Detox diets for toxin elimination and weight management: A critical review of the evidence. Journal of Human Nutrition and Dietetics, 28(6), 675–686. https://doi.org/10.1111/jhn.12286
Turner, P. G., & Lefevre, C. E. (2017). Instagram use is linked to increased symptoms of orthorexia nervosa. Eating and Weight Disorders, 22(2), 277–284. https://doi.org/10.1007/s40519-017-0364-2
Obert, J., Pearlman, M., Obert, L., & Chapin, S. (2017). Popular weight loss strategies: A review of four weight loss techniques. Current Gastroenterology Reports, 19(12), 61. https://doi.org/10.1007/s11894-017-0603-8
Mishori, R., Otubu, A., & Jones, A. A. (2011). The dangers of colon cleansing. Journal of Family Practice, 60(8), 454–457.
Getting, J. E., Gregoire, J. R., Phul, A., & Kasten, M. J. (2013). Oxalate nephropathy due to "juicing": Case report and review. American Journal of Medicine, 126(9), 768–772. https://doi.org/10.1016/j.amjmed.2013.03.019
Navarro, V. J., Khan, I., Björnsson, E., Seeff, L. B., Serrano, J., & Hoofnagle, J. H. (2017). Liver injury from herbal and dietary supplements. Hepatology, 65(1), 363–373. https://doi.org/10.1002/hep.28813
Historical Sources
Nuland, S. B. (2003). The doctors' plague: Germs, childbed fever, and the strange story of Ignác Semmelweis. W.W. Norton.
Chernow, R. (2010). Washington: A life. Penguin Press. [George Washington's death and bloodletting]
Markel, H. (2017). The Kelloggs: The battling brothers of Battle Creek. Pantheon Books.
Whorton, J. C. (2000). Inner hygiene: Constipation and the pursuit of health in modern society. Oxford University Press.
Porter, R. (1999). The greatest benefit to mankind: A medical history of humanity. W.W. Norton.
Industry Data
Global Wellness Institute. (2023). Global Wellness Economy Monitor 2023. https://globalwellnessinstitute.org
Additional Sources
Federal Trade Commission. Dietary supplements: An advertising guide for industry. https://www.ftc.gov/business-guidance/resources/dietary-supplements-advertising-guide-industry
National Institutes of Health, Office of Dietary Supplements. https://ods.od.nih.gov