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Dry Fasting: How it Works, Benefits, Risks, and Safety

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Fasting, a research-backed strategy to improve your health, comes in different shapes and forms. One of them is “dry fasting” in which a person doesn’t just abstain from food, but also liquid. This may seem more difficult than your usual intermittent fast — however, it comes with health benefits for those interested.

This guide cuts through the noise to explain what dry fasting entails, how it could help you, its potential risks, and how to dry fast safely.

What is Dry Fasting?

Dry fasting, also called absolute fasting, is exactly what it sounds like: It means that you fast without consuming any form of liquid. This includes water, coffee, tea, and other calorie-free drinks.

People who hear about dry fasting are usually concerned about the possibility of becoming dehydrated, and rightfully so. It’s not for beginners and may not be the best approach for certain individuals who are at risk — for instance, athletes and active individuals.

Meanwhile, dry fasting can be safely implemented and is unlikely to have any side effects among those who are:

  • Generally healthy
  • Fat-adapted
  • Fasting only for short periods

Dry fasting is comparable to Ramadan, a special time of the year for Muslims, in which they fast from dawn to sunset without food and water (*).

How Dry Fasting Works

Since dry fasting requires that you abstain from liquid (aside from food), it can be implemented within any type of intermittent fasting.

It won’t matter if you’ll be doing spontaneous meal skipping, the 16:8 fast, alternate-day fasting, one meal a day, or a shorter 12-hour fast. On dry fasting, you can implement any of these with the additional rule of making sure you don’t drink anything.

How long can you dry fast? You might ask. The short answer is that it depends on how long you’re able to go without liquids. In other words, you can aim for a minimum of 12 hours if you feel fine.

Keep in mind that fasting, in and of itself, causes the depletion of glycogen in your liver. As your body enters a metabolic state of ketosis, you may find yourself urinating more often. This could lead to dehydration unless you replenish with water and electrolytes.

Types of Dry Fasting

There are two main ways to perform a dry fast — soft dry fasting and hard dry fasting. Here’s how they differ:

Soft dry fast

While you’re not allowed to consume water and other fluids, you can do other things that involve coming in contact with water. For example, brushing your teeth, washing your face, and bathing regardless of how long your fast will last.

It has been said that this type of dry fasting may increase the risk of water getting into your mouth, which defeats the purpose of dry fasting. However, the above mentioned activities allow you to feel refreshed.

Hard dry fast

On the other hand, a hard dry fast forbids coming in contact with water, even if it simply means brushing your teeth or bathing as part of your personal hygiene.

Between a soft dry fast and a hard dry fast, the former option is more comfortable for beginners on dry fasting and may be better mentally. There’s also no evidence showing that a hard dry fast is superior to a soft dry fast in terms of health benefits.

Note: Another way of categorizing dry fasting is by duration. With that being said, dry fasting can be intermittent, meaning that you do it for a small window of time each day, or prolonged, which lasts anywhere from 24 hours or more.

Potential Health Benefits of Dry Fasting

Like regular fasting which allows for zero-calorie drinks, dry fasting benefits are plenty. Here are some of them:

1. Reduced body weight

Many people who undergo a fast do it for weight loss reasons. Studies have found that intermittent fasting can help people lose weight and may be used as a primary approach to treat obesity (*).

However, note that the weight loss resulting from dry fasting in the short term is mostly water weight. You don’t lose fat mass overnight, but you’re likely to see a decline in total weight due to the reduced water in your system.

This is especially true because fasting itself already depletes your body’s glycogen stores, which reduces water weight (since glycogen is bound to water) — on top of the fact that you’re not drinking any more fluids during dry fasting (*).

Doing repeated fasting — whether dry fasting, water-only fasting, or fasting that includes other zero-calorie drinks — will lead to true fat loss over time.

2. Decreased inflammation

The body’s inflammatory response can either be acute or chronic. While acute inflammation is more noticeable (e.g., pain, redness, and swelling) chronic inflammation is subtle and may be caused by an autoimmune disorder, too much stress, and an unhealthy high-sugar diet.

Dry fasting has the potential to reduce and improve diseases caused by inflammation, such as diabetes, heart disease, arthritis, and bowel diseases (*).

In a 2012 cross-sectional study, healthy male and female subjects did Ramadan fasting. At the end of the third week, their proinflammatory cytokines (which are released during inflammation) were significantly lower (*).

They also had lower blood pressure, body weight, and body fat percentage.

3. Induces autophagy for anti-aging

There’s evidence that dry fasting may result in delayed aging. Fasting triggers autophagy, which is a natural process in your body that involves getting rid of damaged or dysfunctional cells (*).

Autophagic activity decreases with age, and this causes damaged cells to accumulate. Not just that, but decreased autophagy has been found to make age-related diseases worse, such as cancer and Alzheimer’s disease (*).

Through dry fasting, you can restore homeostasis and increase DNA repair. It also increases the number of your mitochondria, helping you age healthily (*).

4. Helps with insulin resistance

Another benefit of dry fasting is that it improves insulin sensitivity or the responsiveness of your cells to insulin.

A 2015 study done on healthy males who fasted during Ramadan noted a significant increase in insulin sensitivity and decreased insulin resistance after four weeks of intermittent fasting. Additionally, the subjects lost an average of 1.52 kg (*).

Boosting insulin sensitivity reduces your risk of diseases, such as prediabetes, type 2 diabetes, obesity, and heart disease (*).

5. Skin health

Dry fasting can improve your skin in different ways.

One is that reduces the likelihood of acne breakouts caused by high insulin levels (*). Another is that fasting may accelerate wound healing as it enhances endothelial angiogenesis — this describes the migration, growth, and differentiation of endothelial cells (*).

Fasting, especially when done regularly in combination with a sugar-free diet (like keto), can help reduce the appearance of wrinkles. Your diet affects your skin appearance and too much sugar damages collagen in your skin, ultimately leading to more wrinkles.

Side Effects of Dry Fasting

People who are new to dry fasting or any type of fasting may experience short-term side effects. Expect the following symptoms:

  • Dry mouth
  • Increased thirst
  • Hunger pangs
  • Low energy
  • Headaches
  • Inability to focus
  • Mood swings
  • Increased urination (but this is followed by decreased urination since you’re not drinking water until the end of the fast)

These dry fasting side effects are similar to when you’re new to the keto diet. With dry fasting, it’s usually because you’re entering ketosis combined with diminished fluid intake.

Potential Risks and Complications of Dry Fasting

Is dry fasting safe? It depends on the person doing the dry fast since it carries risks for people who are most likely to get dehydrated.

This includes athletes, avid exercisers, people living in warmer climates, uncontrolled diabetes, older adults, and those taking medications that increase urination (e.g., blood pressure meds, diuretics, and antidepressants).

Remember that the longer the dry fast, the higher the likelihood of becoming dehydrated. Dehydration as a result of prolonged dry fasting has complications, such as low blood volume, heat stroke, seizures, kidney damage, and coma.

We recommend starting with regular fasting (where you’re allowed to drink water and other zero-calorie fluids) before jumping into dry fasting. Also, keep your dry fasts as short as possible. End your fast right away if you feel ill or experience unusual symptoms.

Reach out to a healthcare provider to discuss dry fasting before trying it, especially if you have a medical condition.

How to Prepare for a Dry Fast

Before doing a dry fast, make sure that it’s the right option for you. Keep in mind that dry fasting isn’t optimal for everyone since there are instances where staying hydrated is absolutely necessary.

If you’re new to dry fasting, it would be a good idea to ease into it. Restrict food and water for a few hours — let’s say 4 hours — and gradually increase those hours until you feel comfortable with a full 12-hour fast. From there, you can proceed to a 16-hour fast, then a 24-hour fast.

The idea is to allow your body to adjust.

As for your pre-dry fasting meal, we recommend focusing on healthy fats, protein, and complex carbohydrates. Examples are eggs, grass-fed beef, fatty fish, cruciferous vegetables (like cauliflower and broccoli), avocados, and berries. Check out these top intermittent fasting foods for your feeding window.

Stay away from highly processed and sugary options since these will lead to blood sugar spikes, causing you to feel hungrier later on (*).

How Long Should You Dry Fast?

Like regular intermittent fasting, you can dry fast for 12 to 24 hours according to your level of tolerance. Remember to start slow. Here are some common dry fasting schedules:

  • 16:8 – restricting food and water for 16 hours, followed by a feeding window.
  • 20:4 – eating and drinking within a 4-hour window and fasting for 20 hours.
  • Alternate-day fasting – fasting for 24 hours every other day.
  • One meal a day – OMAD for short, this is when you fast for 23 hours and consume all your calories from food and drinks within a 1-hour eating window.

As you can see, there are plenty of ways to dry fast. Feel free to try each one, and be mindful that what works for others won’t always work for you.

How Often Should You Dry Fast?

There are no definitive rules on the number of times you should fast. Whether you do it once or twice a week, or a few times each month, make sure to follow a healthy diet in general.

What you eat around your fasts — pre-fasting and post-fasting meals — will fulfill your nutritional needs, influence weight loss, and reduce your risk for disease.

How to Break Your Dry Fast

Break a dry fast properly with nutrient-dense, unprocessed, low-glycemic, and easy-to-digest foods.

Excellent options include bone broth, fermented foods (kimchi, sauerkraut), eggs, and fatty fish. Plan these meals ahead so that you wouldn’t end up breaking your fast with unhealthy foods. Simple carbs like white bread, pasta, and pastries are the worst foods to eat.

Practice mindful eating by chewing your food slowly and savoring it. Stop when you’re about 80% full.

And last but not least, replenish electrolytes. You can consume Perfect Keto Electrolytes or simply blend pink Himalayan salt, lemon juice, and stevia in water.

Who Should Not Dry Fast?

Dry fasting is not ideal for the elderly, women who are pregnant or breastfeeding, and individuals with a history of an eating disorder. Additionally, you should check with a doctor first if you have a medical condition.

Frequently Asked Questions

Below are common questions and answers relating to dry fasting:

What’s the difference between dry fasting and water fasting?

Dry fasting restricts both food and water for an extended period, whereas water fasting (or “water-only fasting”) restricts food but allows you to consume water. Water fasting helps you reap the benefits of autophagy without the risk of becoming dehydrated.

Can you exercise while dry fasting?

While exercise isn’t forbidden on any type of fast, note that exercise makes you lose water from sweating. If you don’t replace fluids, you raise your risk of dehydration. Instead of exercising in the middle of a dry fast, consider doing it during your feeding window.

Can I eat food during dry fasting?

The only time you’re allowed to do that is at the end of a fast. Break your fast with foods and drinks full of vitamins and minerals, and that do not contain too many carbs.

The Bottom Line

Because dry fasting doesn’t allow any fluid intake, it’s not the best approach for people who haven’t tried regular water fasting previously and those who are most at risk of dehydration.

In contrast, it can be easier for those already on the keto diet and are metabolically flexible.

Like regular fasting, dry fasting benefits include weight loss, decreased inflammation, slower aging, better insulin sensitivity, and clearer skin.

The tips we’ve just shared will help you with dry fasting as a beginner but speak with a healthcare provider for further guidance and advice.

13 References

Urooj A et al. Effect of Ramadan Fasting on Body Composition, Biochemical Profile, and Antioxidant Status in a Sample of Healthy Individuals. 2020 October 31

Can Fam Physician. Intermittent fasting and weight loss. 2020 February

Shiose K et al. Segmental extracellular and intracellular water distribution and muscle glycogen after 72-h carbohydrate loading using spectroscopic techniques. 2016 July 11

Pahwa R et al. Chronic Inflammation. 2022 August 8

Faris M et al. Intermittent fasting during Ramadan attenuates proinflammatory cytokines and immune cells in healthy subjects. 2012 October 4

Bagherniya M et al. The effect of fasting or calorie restriction on autophagy induction: A review of the literature. 2018 August 30

Barbosa M et al. Hallmarks of Aging: An Autophagic Perspective. 2019 January 9

Urooj A et al. Effect of Ramadan Fasting on Body Composition, Biochemical Profile, and Antioxidant Status in a Sample of Healthy Individuals. 2020 October 31

Gnanou J et al. Effects of Ramadan fasting on glucose homeostasis and adiponectin levels in healthy adult males. 2015 July 7

Prasetya G et al. Intermittent Fasting During Ramadan Improves Insulin Sensitivity and Anthropometric Parameters in Healthy Young Muslim Men. 2018 December 2

Przytocka A et al. Insulin resistance in the course of acne – literature review. 2021 June 18

Luo M et al. Fasting before or after wound injury accelerates wound healing through the activation of pro-angiogenic SMOC1 and SCG2. 2020 February 19

Ball S et al. Prolongation of satiety after low versus moderately high glycemic index meals in obese adolescents. 2003 March

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32 thoughts on “Dry Fasting: How it Works, Benefits, Risks, and Safety

  1. I did a 48 hour dry fast with absolutely no problems whatsoever. It improved my balance, which means it improved my brain.

    1. Hi. I am doing a 90 hours dry fasting. 42h have passed, I feel still great and continue doing what is planned.

  2. Thank you for this well-researched and very informative article. It’s an eye-opener. I really appreciate quality content like this!

  3. I have done 3 times 3 days dryfasting. one 6 days dry fasting and one 7 days dry fasting.
    the last one l lost 9 kilos, and gain back 6 kilo, but one month after ending the 7 days dry fast, I lost another 2 kilo of body fat.
    Because I do OMAD 22 hours fastimg 2 hours eating.
    I just started another dry fast, lost 4 kilo the first day, so now l am on the same waight as when l finnish the last dry fast. I am OK not tired not tirsty, just a little bit under normal.
    I am dry fasting to get rit of my stuborn belly fat. plus my body will be cleant up again. I had pimples every time l grow a beard, now l have a beard again, but no pimples.
    so the dry fasting has cured my skin.

  4. I did 72 hours dry fast,was dizzy on day three kept pushing.i broke my fast and next day had a minor stroke.This was not my first time doing this .I had successfully done it before so it wasn’t something really difficult for me I thought I could help so.eine out there

  5. This is flawed as the studies you mentioned didn’t include a control study. A ramadan study is inherently flawed because – it doesn’t compare benefits of dry vs wet fasting. You need to provide more specific studies.

  6. I know this is not a scientific study, but many of the Muslims I know gain weight during Ramadan because they eat massive amounts of goodies before dawn (think Christmas treats but for Ramadan) and then again after sunset. My Palestinian neighbor even jokes about having period and Ramadan pants she can wear for that bloated, overnight weight gain.

  7. I did my first 25 hour dry fast last week, I feel great my mind is awaken compare to my water fast for several months. This is amazing! Even 16 hours, 12 hours dry fast every day, I enjoyed the feeling of having always an extra energy. I just notice even I don’t get enough sleep, like I can wake up from 3 or 4 hours sleep and work all day and still has the energy to workout in the afternoon and in the evening. Mind you, I work in a call center where I have to wake up and work from 1AM to 10AM, still the energy is there. This is much better than my water fast.

  8. I just completed a 60 hour hard dry fast. My first time. I did prepare for this hard dry fast with a week long soft bone broth fast. Meaning, I did have some of the onions celery garlic and meat off the bones that I used to make my bone broth. The last time I ate from my broth was Friday at noon. At 11:45 pm I washed my hands after work and I didn’t touch water again until Monday at 12:45pm. Through out the first day of the fast I had a minor migraine on the left side of my head. Nothing I couldn’t handle. It was gone the last half of the fast. Now a day after my 60th hour I’m not feeling great. I feel like I have a low grade fever. The headache is now more like a tension headache. I have some weakness. I broke my fast with 1 liter of coconut water. I drank the liter within the first hour. My second hour after breaking my fast I drank 1 liter of water. My third hour two liters of water. I felt fine. Functional. So I slowly returned to my normal routine. I had another liter of coconut water over an hour before work. I had to work at 7pm. Thought I should eat so I have some energy. Just in case. I didn’t want to be drained. I had rice chicken and some vegetables carrots zucchini squash. Big mistake!!! I had bad diarrhea. I thought I was gonna have to go home but I pushed through with no further bathroom incidents. I wait tables so I did a lot of walking and carrying plates. Just to give you an idea of the type of stress I put my body under. My upper back was hurting like an 8 on a 1-10 scale. I didn’t feel my best the whole time there but it was bearable. I’m a little concerned about my time in the bathroom. I thought maybe some bile dump from the liver or something. Maybe dehydration or stressed renal function. I don’t know. I have read online that a teaspoon of baking soda with water will help the kidneys. Is this a necessary step after a hard dry fast? Also what does the mixture do for the kidneys?My wife works in a hospital and thinks I might be dehydrated to the point of renal failure due to my feeling ill and weak. I’m just trying to gain some knowledge because I plan to make fasting a part of my lifestyle for the health benefits and I wanna make sure I don’t go through anymore bathroom incidents. Lol. If someone has any answers or pointers I would really appreciate that. Thanks. Emilio.

  9. Emilio,
    I have been been doing different length of hard dry fasts ove last 2 months and everyone has been somewhat different. one

  10. Emilio, Ive done about 8 hard dry fasts of varying duration, 2 to 7 days. Everyone has been somewhat different, it is getting easier tho. had an exit from fasting similar to yours, but it hasnt happened again. Ive used the baking soda many times within the first hour after exiting my fasts with no ill effects but Im not sure it helps anything either. Wont hurt to try. in Sergei Filonov’s book, Dry Medical Fasting/ myths and reality. There is a simple example of exiting a dry fast that Ive tried, it is simple and used for whatever the duration of the fast.
    Slowly drink water for 2 hours after exiting fast then eat yogurt or keifer, plain of course, only for the next 2 hours. then slowly resume healthy vegis and whatever you tolerate after that. I found that to be simple and without any problems for me. Just an example I thot to pass along.The yogurt only helps reestablish bacteria I guess, and it is very mild on starved stomach. Blessings on your dry fasting journey! Dry fasting is the bomb!!!!

  11. This has been a great read and inspiring on cleansing as a whole. I’m on day 8 of a water fast and saw in another article about dry fasting. I looked up dry fasting and it brought me to this page. I am going to try and do a dry fast this weekend. I’m excited. Thank you everyone who shared their experience.

  12. We in India, specific Hindu community do the Dry fasting for 36 to 40 hours every fortnight ( 2 times in a period of 30 days) and the day is called “Ekadasi” – 11th day of Hindu Calendar. It helps a lot and many individuals are very very Healthy.

  13. Thanks for the great article! I think intermittent dry fasting is quite normal. Honestly, without even really realizing it at the time, I’ve been doing these short dry fasts for decades. You know how you go out for dinner on Friday evening, then sleep in late on Saturday and get up and start doing stuff around the house without eating breakfast or drinking anything? Several hours go by and your like, “Oh, wow, time has flown by. I guess I should go eat” and it’s like 3 or 4 in the afternoon. Or that will happen on Saturday to Sunday.

    I’ve been dry fasting for the last 19 hours and I feel fine and don’t plan to eat or drink until dinner tonight, but then again, I’m keto/fat-adapted and have done 18/6 IF every day for the last few months in addition to a few 24-hour water fasts.

    Rao, that’s so interesting! I didn’t realize that. I’ve often noticed that you rarely see overweight Eastern Indians. Ekadasi must be part of the explanation.

  14. 9.oclock tonight will be 3 days into this dry fast, never thought a dry fast is good for you as long as you follow what is outlined in this article. I saved my life in 2004 I was 300 lbs and had issues did a 36 day water fast, after 3 days I was not hungry the toxins that I peeded out I was going for 40 days but was talked out of it. I did a 21 day water fast in 2017 and worked every day, another 21 day in late 2018 each time felt no hunger ,I believe totally that it is all mental, if you’re mind thought is you can’t do it then don’t even attempt it?

  15. So I accidentally broke my fast twice today, once at 0800 with honey in my coffee, then again in the afternoon by drinking a g2 gatorade (about 100 calories), which I did at 1700. Do these 2 beverages delay me from going into ketosis significantly, even though I know I have burned them off today?? My plan is to resume my food/drink tomorrow at dinner. (48 hour dry fast originally planned, but will actually be 24 hours dry dry). How much of that 48 hours really count??

  16. I m also doing Ekadashi as 36 hours dry fasting—- without water and food… my body start cleansing during the dry fasting Coz you are not feeding food and water to your stomach ,, so body don’t work to digest food and water and like our weekends body can do extra work of cleaning the body… but every morning and night before sleep I take water enema by myself… which push out extra waste of body in form of hard stool..

    Emilio did a mistake while breaking the fast… when you stop food and water supply to yor body… you should not start in a bulk

  17. I have dry fasted once before and had to stop for personal reasons. Today, at noon I decided to try a dry fast (soft), and have been doing it for 9 hours and 17 minutes now. I think I might try to pursue this further until morning. Approximately 6 am which will be 18 hours. Thus far, I am feeling ok and starting to feel pretty good. I have headaches on a water fast and have no headaches at all through the past 9 hours. I do have a heart burn; I am not hungry or thirsty however. The only thing I am concerned about is whether or not I will be able to sleep because my energy level is through the roof.

  18. I intuitively did my first Dry Fast one week ago… why? PMS and water retention. I thought “all the “protocols” for PMS bloating and water retention say “drink more water” and that doesn’t work for me as I retain that and feel more bloated, so why not try the opposite” .. so I thought to dry fast for min 12 hours to see if it made a difference… and yes it did.. I actually pee’d more, than if I was drinking water during PMS, I didn’t feel bloated and slept well (during PMS that’s always questionable)… AND actually went to the toilet with ease the next morning (whereas constipation is a PMS mainstay for me, sorry TMI) Also Dry Fasting is much easier to do that fasting with water… I have no hunger during my fast stage (I only do around 16-18 hours) So basically I did a George Kastanza and did the OPPOSITE of PMS protocols… and for me it worked. I listened to my body and it told me what it needed…funny that.

  19. I have dry fasted for 24 hrs successfully three times. It was a miracle cure for getting rid of my arthritic knee pain, and bilateral torn meniscus. Works so well I do it now every two weeks. For anyone out there suffering with pain in your joints or back this truly works like a charm. I’m not on pain meds any longer with exception of a mild anti inflammatory if I’ve had an over busy or long day.. This dry fasting has changed my life and a sincere answer to prayer…from the heart, Vicki

  20. That’s so wild to hear these guys in the video saying that they had such a hard time with dry fasting. I routinely (like weekly or at most monthly) go without water for 16 – 24 hours simply by just being busy and doing a tiny bit of effort. I have to make myself drink water so for me it’s very easy to dry fast. In fact, right now I have not had any food or water since last night at about 7pm and it’s now 9pm the next day. That’s 26 hours and I feel totally normal. I’m getting a little growl in my stomach and will probably go eat something in a bit but not a big deal.
    I can’t imagine it being so difficult to go 24 hours without water. To me a 3-day water fast would be much harder. I like food! 🙂 Maybe I’m just adapted to be able to handle it by the fact that I’ve never been a big water guzzler. I’m 51 now and still have to MAKE myself drink when I don’t feel thirsty during the day and sometimes i just don’t want to force myself, even though I know I’ve only had about 50 ounces of water/liquids that day.
    Maybe there are genetic differences in people’s need for water. I remember as a child in elementary school, when we would all come in from the playground, we would go down the hall in a single-file line and then visit the water fountain. All the kids would drink and I remember I almost never did. I just didn’t have the urge. Maybe the other kids played harder than me. That’s possible since I am an introvert.

  21. Hi, nice article. Would like to mention that a 24/36 hour dry fast is practiced in Hinduism once a year. On days called “Ekadasi” (11th day after new/full moon), generic fasting (36 hour water fast) is practiced (along with staying awake the whole night). However once in a year around May/June a dry fast is suggested.

    1. Technically you would be avoiding them if you are truly dry fasting but that’s why this approach may not be for everyone @Mark

  22. My longest is 6 days (145 hours). I do 2 five days dry-dry fasts per year, and a bunch of 72 hour ones. My next one I will go 170 hours. Profound experience. I learned a lot and willing to share my knowledge and experience.

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