Headaches, feeling cold, hunger during the juice cleanse?

Most complaints during a juice cleanse occur because your body is adjusting. It is receiving less energy, less salt, and no more coffee. You will feel this especially in the first two days. After that, it usually becomes significantly calmer for many.

An important note upfront: not every complaint during a juice cleanse is harmless. Severe symptoms are not a sign that the cleanse is working particularly well. They are a signal you should listen to. Whether a cleanse is right for you in principle is explained in our article on who a juice cleanse is suitable for.

Headaches are the most well-known complaint during a juice cleanse. The most common reason is often not the fasting itself, but coffee. If you usually drink two or three cups every morning and suddenly stop, you get caffeine withdrawal on top of it.

A randomized study with 100 regular coffee drinkers shows this clearly. On days without caffeine, 30 percent had headaches, compared to only 10 percent on days with coffee (Randa and colleagues, 2026). Abstaining therefore doubled the risk, and the pain was more severe. This is exactly the effect many coffee drinkers experience on the first morning of a juice cleanse. In addition, many people drink too little during a juice cleanse because they already count the juices as liquid intake.

What helps you is, above all, planning. Slowly reduce your coffee intake in the days before instead of cutting it out overnight. How to succeed is shown in our article on juice cleanse preparation. In addition to the juices, drink water and herbal tea, spread throughout the day. The German Nutrition Society (DGE) recommends at least 2.5 liters a day during therapeutic fasting (DGE, 2018). A walk in the fresh air often does additional good.

Many notice it in their hands and feet. You feel colder faster during a juice cleanse, even if the room is not cold at all. A review article lists cold sensitivity and lower blood pressure as common companions of a severely restricted diet (Swiss Journal of Nutritional Medicine, 2022). Your body has less energy available and reduces heat production slightly.

In the first few days, you also excrete more water and salt. This can strain the circulation, especially when standing up quickly. Therefore, stand up slowly in the morning and sit on the edge of the bed for a moment. A major health insurance company explicitly names shivering, circulatory problems, and fatigue as possible companions of juice fasting (Angestellten-Krankenkasse, 2025).

What helps against feeling cold is what sounds old-fashioned. Dress in layers, keep a hot water bottle ready, and drink warm tea. Light exercise gets the circulation going; a short walk is enough. A warm foot bath in the evening can help you fall asleep. Feeling cold during a juice cleanse is unpleasant, but in itself is no cause for concern as long as your circulation remains stable.

Hunger during a juice cleanse is rarely a genuine lack of energy. Much more often, it is habit. At twelve, there was usually lunch, at four a snack, and the body reports in at the usual time. This feeling often comes in waves and also passes again.

A juice cleanse provides more energy than classic therapeutic fasting. According to nutritional information, the BETTER JUICE CLEANSE PLUS provides between 731 and 885 kilocalories a day. With Buchinger fasting, it is only 200 to 250 kilocalories. Even in that case, in a large observational study with 1,422 people fasting, over 93 percent stated that hunger was not a problem (Wilhelmi de Toledo and colleagues, 2019). The participants were, however, medically supervised.

What helps is structure. Drink the juices at fixed times that are oriented towards your old mealtimes. If a wave of hunger hits, first take a large glass of water or tea. Also, find a distraction, ideally something that has nothing to do with food. A phone call, a short walk outdoors, or a book will carry you well through a wave of hunger during a juice cleanse. How much is in which juice is shown in our article on calories and sugar in a juice cleanse.

Most complaints during a juice cleanse are annoying but harmless. In the study mentioned, serious side effects occurred in less than one percent of participants (Wilhelmi de Toledo and colleagues, 2019). Nevertheless, there are signs that indicate you should not continue. During a juice cleanse, pay close attention to how your body feels, especially in the first two days.

• severe dizziness or the feeling of being about to faint
• heart palpitations or an irregular heartbeat
• very severe headaches, especially accompanied by visual disturbances
• tremors, weakness, and confusion
• complaints that get stronger rather than weaker after the second day

In these cases, stop the juice cleanse and eat something light, such as soup. For severe or persistent complaints, seek medical advice. Health insurance providers also recommend incorporating an easily digestible meal if you feel unwell (Angestellten-Krankenkasse, 2025). This is not a failure. How to properly interrupt a cleanse is explained in our article on interrupting or stopping a juice cleanse.

Headaches, feeling cold, and hunger during a juice cleanse are common and usually harmless. They occur primarily at the beginning and have clear causes, most notably the lack of coffee, too little fluid intake, and the new routine.

With preparation, warmth, water, and fixed times, you can minimize most discomforts. A simple rule applies to strong or persistent symptoms: your body takes priority over any plan—if you feel unwell, stop the juice cleanse.