What a Juice Cleanse Actually Does to Your Body

Juice cleanses are everywhere on Instagram, in influencer routines, and in glossy bottles lined up at your favorite health food store. Promising everything from rapid weight loss to glowing skin and “detoxified” organs, these liquid diets have become a go-to for those seeking a quick health reboot. But what really happens to your body when you commit to a few days of sipping instead of chewing?

Spoiler: The effects might not be as magical or long-lasting as you think.

What Is a Juice Cleanse?

A juice cleanse typically involves drinking several servings of fruit, vegetable, and nut-based juices per day usually six bottles for anywhere from three to ten days. During that time, no solid food is consumed.

The idea is to flood your system with vitamins while giving your digestive tract a “break.” But despite the wellness buzz, most experts agree: juice cleanses are not a sustainable or science-backed way to detox your body or to maintain weight loss.

You May Lose Weight… Temporarily

Many people try juice cleanses hoping to shed a few pounds quickly. And yes, you may see the number on the scale drop within the first few days. But according to Samantha Cassetty, RD, much of that is water weight, not fat loss.

When you severely limit calories, your body taps into glycogen (carbohydrate stores), which also releases water. This can lead to quick, noticeable weight loss that returns just as quickly once you resume eating normally.

You may also shed water due to reduced sodium, since packaged foods the main source of sodium are cut out.

But You’ll Probably Gain It Back

After a cleanse, your body naturally works to restore fluid and energy balance, says Natalie Stephens, RD, which means the weight you lost may come back within 72 hours of your first real meal.

Without a long-term strategy, juice cleanses don’t provide lasting weight management. As Jane S. Sadler, MD puts it, “A lower-calorie diet is more sustainable than giving up food entirely.”

Your Metabolism May Slow Down

Some juice recipes contain cayenne pepper, known to give a slight metabolic boost. But the effect is minor and doesn’t outweigh the impact of consuming fewer than 1,000 calories per day.

When your body senses food scarcity, it adapts by burning fewer calories to conserve energy a survival mechanism that may slow your metabolism and make long-term weight loss more difficult.

You’ll Likely Feel Hungry and Irritable

Juices are low in key nutrients that promote satiety, like protein, fiber, and healthy fats. Without these, you may feel constant hunger, low energy, and even mood swings.

“You're likely to be really hungry, irritable and potentially even anxious,” says Cassetty.

Plus, most juices contain more fruit than you'd normally eat in one sitting think the sugar of three or four apples in one drink without the fiber to help you feel full. This can lead to overeating once the cleanse is over.

You Could Experience Digestive Upset

While some people do juice cleanses hoping to improve digestion, they may end up with the opposite result. A low-fiber, high-acid diet like a juice cleanse can lead to:

• Heartburn

• Bloating

• Constipation or diarrhea

• Sleep disturbances (from hunger or frequent urination)

As Dr. Sadler notes, “No one should go to bed hungry” especially not for days in a row.

The Detox Myth: Debunked

One of the most common (and misleading) claims about juice cleanses is that they "detoxify" your body. In reality, your liver, kidneys, lungs, and digestive system already do a great job of eliminating toxins naturally.

“There’s no scientific evidence that juice cleanses speed up or enhance liver detoxification,” says Cassetty.

Your body doesn't need a cleanse it needs consistent, balanced nutrition to keep functioning at its best.

A Better Approach to Feeling Your Best

Instead of turning to extreme cleanses, focus on sustainable, science-backed habits that support energy, digestion, and weight management:

• Drink more water throughout the day

• Load your plate with fiber-rich fruits and vegetables

• Eat lean protein and healthy fats at each meal

• Try gentle, time-based eating strategies like intermittent fasting, which early research links to reduced inflammation and better metabolic health

The Bottom Line

Juice cleanses may deliver short-term weight loss and the illusion of health, but they’re not a sustainable or necessary path to wellness. In fact, they can disrupt your metabolism, mess with your digestion, and foster an unhealthy relationship with food.

“Most people can survive a few days of hunger,” says Cassetty, “but a juice cleanse doesn’t teach you how to nourish your body long-term.”

Instead, focus on progress not perfection. Your body thrives with real, whole food and consistent care not flashy quick fixes.

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