Pills, powders and potions: the reality of taking supplements while fasting

One question which persistently recurs on waterfasting.org is whether or not you should take supplements while water fasting. The majority of people want to know about vitamin supplements and, occasionally, even protein supplements. In this article I’ll deal with both, as well as other kinds of pills, powders and potions…

There are some people who take a hardline approach to water fasting – in other words water, water, only water. Personally, I do drink only water when I’m fasting, but I believe that everyone needs to find their own solutions, depending on the reasons that they’re fasting. This may include drinking herbal or green teas, or perhaps adding a slice of lemon to their water.

Taking supplements, though, is another step removed from the simple purity of drinking only water.

Vitamin supplements

Many people believe that they need to take vitamin supplements in order to live a healthy life. When it comes to fasting, this belief often takes on an added urgency. The logic – at least on the surface level – is sound, and goes something like this: ‘If I need to take vitamin supplements when I’m eating normally, then surely I need them even more when I’m not eating anything at all!’

Yes, in one sense the logic is sound. The only problem is that it’s based on the logic of your everyday working digestive metabolism and not the healing metabolism of ketosis, which takes over during a water fast and works completely differently.

I would suggest taking another approach – one which instead follows the logic of your healing metabolism:

So long as things are going into your body, toxins can’t come out of your body.

Whenever possible, it’s best just to get out of the way, and let your body get on with the business of cleansing and detox.

Okay, it’s true: toxins can’t come out of your body while food and calories are going in. It’s equally true that most vitamin supplements don’t contain calories. They won’t affect ketosis or radically change the biology of your fast. And so, in this sense, there’s nothing wrong with taking them.

Nevertheless, even if taking vitamin supplements doesn’t adversely affect ketosis, what good does it do to the fast? The truth is: little or none. They only distract your body and get in the way of natural cleansing and detox.

I’ll come out with it plain and simple: so long as you’re healthy, there’s no need to take vitamin supplements while fasting, and this is certainly the case if you don’t normally take supplements in everyday life. It’s also the case if you’re considering an extended healing fast and are worried about chronic vitamin depletion. No-one has ever died from vitamin deficiencies while fasting!

Instead, try to trust your body. It really does know best.

Humankind has been fasting for thousands of years, well before modern science came on the scene with ideas about vitamin supplements :-). I doubt our ancestors on the African savannah or in ancient India worried about it. They just got on with their fasts, trusting that their bodies would get on with the business of cleansing and detox.

It simply wasn’t a problem.

There are those who rightly say that the nutritional content of food is much lower nowadays than before monoculture (mass cultivation of one particular crop) revolutionised agriculture after World War II. This also means specifically that the vitamin content of what we eat nowadays is much lower than in the past.

Sad but true. Nevertheless, vitamin content hasn’t decreased to the point that it affects fasting. While fasting, the body conserves its essential reserves, and this includes vitamins.

If you’re worried about vitamins, a much better solution would be to eat organic in everyday life than take vitamin supplements while fasting.

Vitamin supplements for health issues

Okay, so if you’re healthy there’s no need to take supplements, but what if you already have a chronic vitamin deficiency?

This implies that you’ve already discussed the matter with your doctor. My advice, therefore, would be to return to your doctor and ask if it’s okay to stop taking vitamins temporarily: for a few days or whatever the duration is of your planned fast. If you have no other underlying health issues, there’s no need even to mention the word ‘fast’ if you feel that your doctor might panic or throw a temper tantrum – because it’s certainly true that the majority of MDs still don’t understand fasting or the benefits of fasting. Most likely, they’ll simply oppose the idea point blank. However, the reality is that in most cases skipping your vitamins for a few days won’t be a problem. Why? Because if it’s a chronic deficiency to begin with, you’ll probably need at least several weeks to regain healthy levels anyway, which means that only a few days without vitamin supplements won’t impact significantly on the long-term effect. Even so, do check with your doctor, especially if you’re planning a longer fast.

If you do have other underlying health issues which require you to take vitamin supplements, my advice would be to find a doctor who does understand fasting and discuss the particulars of your case.

The reality of taking protein supplements while fasting

This one is really easy. The answer is no, no, no!

Protein contain calories – 4 kcal/g to be exact. This is, in fact, exactly the same energy content of carbohydrates, which likewise contain 4 kcal/g.

In other words, if you’re taking protein supplements, you’re not fasting!

Why are we obsessed by the idea of taking supplements?

What causes so many of us to agonise over protein and vitamin supplements while fasting?

If you really think about it, the whole idea is crazy. Fasting means not eating. Taking supplements is its own form of eating. The two are totally contradictory.

Americans, in particular, worry about protein intake, despite the fact that the average American consumes more protein than anyone else on the face of the planet! Isn’t this also totally contradictory?

When people think and act in a contradictory manner, invariably a strong emotion is directing the decision-making process.

Nine times out of ten, fear is the driving motivation behind the belief that you ‘need’ to take supplements while fasting.

Why? Because big business has a lot of money invested in protein and vitamin supplements. Which means they have a lot of money invested in you buying their products. They want to convince you that you ‘need’ them.

How? By implanting fear: fear that without vitamin and protein supplements, you won’t make it through the day.

It’s no wonder these vested interests succeed in brainwashing so many people. Of all emotions, nothing is stronger than fear in influencing our behaviour. And given the consumer messages constantly bombarding us from ‘Big Food’, of course eventually we take the bait.

According to a recent article in the New York Times, Americans spend $30 billion dollars annually on vitamins, minerals and herbal supplements.* If protein powders are included, this constitutes as big a market as the entire organic food industry. In fact, pills, powders and other magic potions make up 5% of all grocery sales in the United States. Isn’t that crazy too?

Deeper fears

This isn’t the end of the story quite yet. Another issue attracts us to the idea of taking supplements while fasting.

The fears instilled by big business work in perfect harmony with and intensify the deeper fears already present in fasting.

It’s totally natural to feel a little fear when fasting. Going beyond your comfort zone in not eating begs the subconscious to carry this through to its logical end, which means playing with the idea of starvation and, ultimately, fear of survival and death (discussed further in my article Facing your Ego).

Even if it’s suppressed in your subconscious, the natural existential fear of fasting – that you won’t make it through the day – resonates perfectly with the fears instilled by Big Food, which likewise infer that you won’t make it through the day without spending lots of money on daily vitamin, mineral and protein supplements.

Supplements, therefore, feel like a way to cheat death. I know this may sound a little extreme, but it’s true. At the very least, anyone considering vitamin supplements while fasting does so because they fear for their health – which, in turn, is only one step away from fearing for their life. After, a total lack of health leads to a total lack of life. In other words, you fear death. Like it or not, the logic is plain and simple.

Water, pure water…

Whenever you’re water fasting and you find yourself seeking alternatives to drinking pure-and-simple water, it’s important to try and understand the reasons. This includes protein and vitamin supplements, but it also includes anything else, such as drinking herbal teas or lemon water.

There can be completely rational reasons for finding excuses not to drink water. For instance, if you have a caffeine addiction, you may find yourself attracted to the idea of green teas, as a means to prevent headaches from caffeine withdrawal symptoms. If you’re fasting for purely physical reasons, there’s nothing wrong with doing what you need to do in order to maximise the chances of finishing your fast. However, if you’re at all interested in what makes you tick, if you’re interested in understanding your subconscious and deeper levels of self, if you’re interested in trying to lead a conscious life, then you should know that usually the reason we look to alternatives besides water has nothing to do with clear logic and rationality.

We may try to justify supplements and teas through logical argument (and most of the time this isn’t too hard!), but deep down inside, there’s usually a deep dark emotion driving us instead. In order to truly make a rational decision about whether or not to take supplements, the best thing we can do is try to dig out those irrational forces inside us, bring them to light, and, making sense of them, act more consciously.

The vast majority of the time, pure-and-simple water really isn’t so bad.
In fact, it’s what we’re made of.


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27 responses to “Pills, powders and potions: the reality of taking supplements while fasting”

  1. Hi Dr. Tallis,

    Is there ever a point when vitamins are required during a water fast?

    I’ve done water fasts for 5-7 days with just water and electrolytes every single day.

    I want to try to water fast 14-21 days but I was not sure if water and electrolytes would be enough for this long of a fast?

    How many weeks of a water fast can we survive on just water and electrolytes without any vitamin supplements?


    1. Tallis Barker, D.Phil. Avatar
      Tallis Barker, D.Phil.

      Hi Jatt,
      Thanks for writing. The vast majority of people are capable not only of fasting without vitamins but also without electrolytes – even on 40-day fasts. Of course, I can’t speak for you personally at this point, but the human race has been fasting for millennia without the need of buying into the supplement industry when they fast…
      Hope this helps,

  2. What’s your take on just probiotics during a fast . Intent : to seed the intestines with healthier flora at an opportune time when no food is competing for the digestive tract’s attention and resources , and where food isn’t in the way.

    1. Tallis Barker, D.Phil. Avatar
      Tallis Barker, D.Phil.

      Hi Jeff,
      Thanks for writing. I’ve never seen any clinical advantage when clients have used probiotics during a fast. Most commercial probiotics do not colonise in the gut, so their beneficial effects are extremely short-lived. I’ve rarely seen any client benefit from probiotics during the refeeding period either, so long as the refeeding protocol is conducted according to appropriate principles. If I were you, I’d invest into top-quality food instead!
      Hope this helps,

  3. I have seen an incredible amount of research on fasting and cancer. Do you know of the metabolic approach to cancer and whether or not fasting for a 21+ day period would shut off metabolic pathways for cancer growth and increase your immune system response to eradicate cancer cells?

    1. Tallis Barker, D.Phil. Avatar
      Tallis Barker, D.Phil.

      Hi Maye,
      Thanks for writing. There’s no question that extended fasting shuts off metabolic pathways which promote cancer growth and facilitates the immune system in identifying and eradicating cancer cells. The issue is rather one of time. It can sometimes take considerably longer than 21 days to start making tangible progress. So in all cases of cancer it’s important to have a fasting strategy which covers different contingencies, based on the actual progress of the fast.
      All the best,

  4. Hi Tallis,
    Thank you for all of your time and work gone into this amazing website. I’m very glad to have found it.

    I’d love to hear your thoughts on electrolytes whilst fasting? Is this something that you keep topped up by taking relevant salts etc, or do you go without?

    Thank you,


    1. Tallis Barker, D.Phil. Avatar
      Tallis Barker, D.Phil.

      Hi Oliver,

      Thanks for writing – and I’m glad you’ve found the website useful!
      If you’re fasting simply for weight loss, electrolytes are fine. But if you want to go deeper into either cleansing or healing they are a definite disadvantage. Many people take electrolytes while faster because they feel better and with more energy, but this is precisely because they’re not detoxing so deeply!!! I need to write an article which goes deeper into the science, because there are a lot of misconceptions out there – some of which are being spread by well-known doctors (without naming names) who simply don’t have the requisite experience in extended fasting.

      Hope this helps,

  5. What about prescription medications? Would these affect the fast or can they be taken as normal during the fast?

    1. Tallis Barker Ph.D. Avatar
      Tallis Barker Ph.D.

      Hi Joe,
      It really depends on the individual drug. It’s best to come off of some medications, while others are best continued. Unless you know exactly how the specific prescription drug interacts with your metabolism, you should discuss this with an MD.
      Hope this helps,

      1. Thanks Tallis, follow up question then. Do I ask my doctor if the medicines would break a fast or do I need to ask something else?

        1. Tallis Barker Ph.D. Avatar
          Tallis Barker Ph.D.

          It’s not that the medicines would ‘break a fast’. Rather, you should ask if fasting will affect (1) whether it’s safe to take them and (2) whether it’s safe NOT to take them. That way you can make an informed decision about what is best for you.

  6. Thank you for your resources Tallis. I am now convinced my body is supersmart. I do eat organic and take vitamins. So I feel reassured I can continue the 40 days of water wasting (currently at day8).
    Do I need to be worry about weight lost at any point in time?
    Can you kindly indicate the link for the post fasting to recover gently into digestion please? How many days of transition?
    Blessings Grego

    1. Tallis Barker Ph.D. Avatar
      Tallis Barker Ph.D.

      Hi Grego,

      Yes, the body IS supersmart!!! To answer your question: assuming you started the fast with a normal body weight, then you should be able to manage 40 days without reaching a dangerously low weight. (This is more likely to happen from around Day 60 or so.) The weight loss that you’re experiencing now – ie. at the beginning of the fast – will start to slow down, so that you’re losing significantly less weight per day. For most people this process starts to happen around Day 10.

      Here is the link to the PDF for refeeding:
      The length of time you’ll need for a full transition back to an everyday diet will depend on your digestion, but expect it to take 15-20 days at least. Please do be careful during refeeding. You need to be very careful after a 40-day fast!

      All the best,

  7. Mackenzie R Diedrich Avatar
    Mackenzie R Diedrich

    Haha! “Never the twain shall meet.” made me laugh! Alright then! Personal challenge submitted!
    But, what about fasting while working? My job can be strenuous, and I’m on my feet for 12 hours. Doing this intermittent fast style, I power through my days mentally sharp, with a constant flow of energy, albeit about 60% my normal fed energy level. I realize I have to fast about twice as long for the same toxin flush, but I’m almost done with day 10, and I went from 206lbs, down to 189 this morning. Should I be doing completely water only fasts on my 4 day weekends, and then feeding for my 3 work days? Would that maximize the ‘fast effect’.

    I would LOVE to be able to take a month long sabatical, and do a fasting retreat where it’s all water, all rest and relaxation, but I simply cannot afford to be away from work even for one week.

    1. Tallis Shivantar Avatar
      Tallis Shivantar

      Hi MacKenzie,

      Whether or not to try water fasting while working is a big question for a lot of people. Most people would NOT feel good if their job was physically strenuous and with such long 12-hour shifts. In some cases, it could be downright dangerous. The only way to guess how you’ll feel while working is to have enough experience water fasting at home while NOT working. If you’re full of energy and stamina at home, then you’ll probably survive work too!

      In terms of what is going to work best for you (you ask about 4-day weekends plus 3-day work weeks), it really depends on what your goal is. On the one hand, you mention your weight. On the other, you mention maximising the ‘fast effect’. Depending by what you actually mean by the ‘fast effect’, these are probably two entirely different issues.


  8. Mackenzie R Diedrich Avatar
    Mackenzie R Diedrich

    I do fasts periodically, and often supplement with bcaas and a protein powder in the morning. I do this because I am still very active, playing softball one night a week, and playing many rounds of disc golf, as well as working my normal 12 hour shifts as a cnc machinist. I realize that taking the supps turns the fast more into a very restrictive Intermittent Fast, and I do see less detox effect..but if I don’t give my body building blocks to repair potentially torn muscle fibers, won’t my body attack the weakened fibers and use them as fuel? Losing muscle mass is one of the biggest fears out there when it comes to fasting as we all know. So is there any credence to following this modified fast for people who cannot afford to simply rest the whole duration, or have physically demanding jobs? If I could go without, I will try it next go round. (currently on day 10/11 of my ‘fast’).

    1. Tallis Shivantar Avatar
      Tallis Shivantar

      Hi Mackenzie,

      Thanks for writing.
      Yes, fear of losing muscle mass is one of the biggest fears out there… As I mention in my article, it’s partly driven by big business and the meat industry, especially in the US. Despite the brainwashing, though, high protein diets are a major cause of chronic illness, especially when combined with a high fat intake.

      In the end, when it comes to supplements, I’d always say that eating is eating and fasting is fasting and “never the twain shall meet!”.

      Like it or not, it’s just a plain fact.

      If you’re putting supplements into your body while fasting, you’re only going to weaken the effects of the fast. It’s ALWAYS better to face your fears and do a full, zero-calorie fast! Not only does this lead to deeper cleansing and detox, it also helps your body to more fully reset its hormonal balance, which in this context also means that it will produce more growth hormone after the fast in order to rebuild any muscle you’ve lost.

      I experience this myself EVERY time I fast for more than a few days. Immediately after the fast I do feel weaker, which is a result of both fat-loss as well as a minimal loss of muscle – and DO remember, any muscle loss incurred during a fast is only going to be a couple of ounces / 100 grams or so, depending on the length of the fast! However, after I’ve broken the fast and the original length of the fast has itself elapsed again (in other words, if I’ve done a 7-day fast, I’m talking about 7 days after the end of the fast), my strength has already done a lot of rebuilding. Over the following weeks I tend to find that my strength actually exceeds my average – precisely because of the higher levels of growth hormone surging through the blood. I find that this increased level of strength continues for about 5-10 times the length of the fast. So if I do a 7-day fast, I find my strength has returned to normal about 7 days after the end of the fast, and then continues at even higher levels for the following 5-10 weeks before levelling off again, back to normal.

      So you might say that fasting actually provides a means to INCREASE strength over the long term!

      Trust your body. It knows what it’s doing!
      If fasting really weakened us, then evolution would have wiped us out millions of years, during the times we had no choice other than to fast out there on the African savannah!


  9. Thank God for this site. I recently completed a 14 day water fast for my first time. It was amazing. I passed a parasite on the eighth day!!! Yes, I’m excited. hahahaha My question is now about viral diseases. I recently contracted hsv 2. have you heard of anyone eradicating this virus? I figure a cancer cell is a lot tougher than a virus. So if water fasting can take care of cancer, I’m assuming it can take care of this virus. I’m gonna shoot for another water fast but this time I’m shooting for 21 days. What are your thoughts on this virus or any viral disease that’s deemed incurable by Western Medicine.

    1. Hi Mike,
      Thanks for writing.
      To cut straight to the chase, no I don’t know anyone who has used fasting to eradicate hsv2 – whether successfully or unsuccessfully. I like your logic though:-). Unfortunately, the way a cancer cell works IS a little different from how a virus does.
      To be honest, I simply have no idea in this particular case how effective fasting will be, but do keep us posted because I’m really curious about the outcome.

      I hope you manage to beat the virus here, and a 21 day fast sounds like a good way to go. In the worst case, even if the virus persists in your body, I suspect the fast will still produce beneficial results by boosting your immune system and reducing symptoms in the process.

      Best of luck to you,

  10. S. Radhakrishnan Avatar
    S. Radhakrishnan

    Dr. Mercola says in an article that during his five-day monthly water fasts he takes in salt five or six times a day. He puts a bit of it on the palm of his hand and licks it off! The article of his which I read was more on salt use in daily life than on water fasting but do you think it holds good for water fasting too? He prefers pink Himalayan salt.

    1. My question is: taking salt five or six times a day???!!!! That seems rather excessive, don’t you think? Unless he’s sweating copiously and in danger of depleting his NaCl, I can’t imagine why anyone would do that. But I also don’t understand why anyone would be sweating to such an extent while fasting. Hmm. Do you have a reference on that article, so I can check it out and find out why on earth he’d do that?

      1. S. Radhakrishnan Avatar
        S. Radhakrishnan

        Please go to http://www.mercola.com, click on “Health” and under it “Health Articles” and enter the following in the “Search” box on top: “Why a Low-Sodium Diet Might Wreck Your Health”. The relevant paragraph is titled “The Importance of Salt When Fasting and Exercising”. I was intrigued by the whole article but nevertheless took it with a pinch of salt!

        1. Haha: a pinch of salt! Well, seeing is believing, and I just don’t understand it. Mercola is absolutely right about salt not being the only factor in causing high blood pressure. Rightfully so, much more important to health is the ratio between potassium and sodium. I’m sure he’s also right about people 500 years ago ingesting even higher levels of salt than today. For me, though, that isn’t quite convincing, because homo sapiens have been around on this planet for many tens of thousands of years, and there’s no evidence that for the vast majority of this time we ate or needed added salt in our diet.

          This applies to fasting too. Of course, you can take added salt while water fasting, but the reality is that you’re going to have to drink more water to compensate for the added salt. There IS an argument to be made for drinking only what you really need while water fasting, because whenever you put ANYTHING into your digestive system – even including water – you stimulate your digestion to some degree. Case in point:

          This last week I finished a four-day dry fast (no eating or drinking of any kind). The point is that, in my experience, dry fasts switch off your digestion much faster than water fasts – precisely because absolutely nothing is going into your body – and doing so consequently accelerates and intensifies your healing metabolism.

          The biggest reason I can see that people would take salt while fasting is addiction. Salt is clearly addictive, and most people are clearly addicted to added salt. For many people, therefore, adding salt during a fast can make you feel more grounded and secure. But it’s not going to help the fast!

          1. S. Radhakrishnan Avatar
            S. Radhakrishnan

            I am generally a bit chary of the pendulum swinging to the other extreme these days in almost every thing to with health – diets, diabetes, blood pressure, salt intake, lipid levels etc. For a couple of decades coconut oil was a villain and now it has turned hero – for someone from Kerala, India where the coconut tree is in our genes this is an awesome turnaround! Similarly fats are now laid on thick! Statins are out. Eggs are back in fashion yolk and all.

            The only sure thing I can trust seems to be fasting of various kinds which brings in varying results and for me the most suitable seems to be water fasts.

            With all the authority of a single 7-day water fast I can say that I did not need any extra reinforcements of any kind in the form of salt or coffee. I stopped taking green tea too on fast days though I do take it on other days when I feel like it, not regularly.

            I use water from a well at home – we have been using this well for three generations – boiled with a few herbs and cooled but more of that another day.

    2. With over 20 years and 100,000+ people gone through a fasting research center in South Korea, they drink a miso tea (two teaspoons of miso) three times a day. This or salt, is a natural way to mineralize.

      They have seen tremendous results. They also put 2 teaspoons of sugar in the raw in warm water – three times a day. With that regimen, they’ve seen cancer, Alzheimer’s, kidney disease and may other health problems eradicated. It’s all in Korean, so sorry you can’t access that information.

      Personally, my kidney function went from 50% to consistently above 100%.

      I also had a bone marrow transplant. The platelet and wbc counts more than doubled and have held. The habit of a three-day water fast once a month has been a life saver.

      1. Hi Jeff,
        Thanks for writing in. I believe they follow a similar practise in Japan too. Certainly, miso is packed with nutrients and it can’t hurt you, and after longer fasts (@ 1 week +) in which mineral levels may start to slowly decrease, the phospherous can help in particular to smooth the road into refeeding. It’s important to note that what you’re talking about is a miso tea composed purely of miso and water, as opposed to miso into a broth or soup. The closer you stay to pure water and not broths/soups, the greater the healing power.
        That’s great to hear that it restored your health so impressively!

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