Conventional belief says you can’t go without water — but after my 36-hour dry fast, I learned just how much our bodies are capable of.
After years of weekly water fasts, I decided to explore a new frontier, something more intense, more ancient, and potentially more potent: a 36-hour hard dry fast. That meant no food, no water, and no contact with water whatsoever. No showers, no brushing teeth—nothing. I had long been intrigued by this practice after studying the work of Dr Sergey Filonov, a Russian physician renowned for his research on dry fasting. His work, including his book Dry Medical Fasting: Myths and Reality, outlines the profound physiological transformations that occur during dry fasting, often surpassing those seen in water fasting.
I began the fast after a long Easter weekend and subsequent week filled with indulgence: rich meals, more wine than usual while catching up with old friends who’d come to stay, and generally pushing my body beyond its comfort zone. I felt puffy, inflamed, congested —especially in my sinuses — and intuitively knew I needed a reset that went deeper than water fasting could provide.
The experience
By hour 12, my mouth was noticeably drier than during water fasts. Thirst came in very small waves but quickly abated. And interestingly, hunger was absent. This was surprising as typically on water fasts, I experience a window of hunger around the 18-hour mark, which subsides by day two, and I’m always thirsty and drinking when water fasting, conscious of having enough electrolytes and hydration. This time, my body seemed to switch into a deeper metabolic state more rapidly. The likely explanation? The compounding stress of food and water deprivation accelerated my transition into ketosis and autophagy.
By 24 hours, the clarity set in – a little euphoric, but mostly neutral, grounded, and deeply still. It was like my body had turned inward, conserving, cleaning, and recalibrating. I could almost feel it taking place internally at one stage. One of the most striking changes was the sudden clearing of my sinuses. After a week of post-Easter congestion, they opened up entirely. I could breathe freely for the first time in days.
The science behind why dry fasting feels so different
Dry fasting triggers unique metabolic adaptations that go beyond what most people associate with fasting.
- Endogenous water production
This blew my mind: the human body has the ability to generate water internally by breaking down fat. It’s called metabolic water, and for every 100g of fat metabolised, we produce approximately 110g of metabolic water.
This means the body isn’t dehydrating — it’s activating. It’s using your fat stores not only for energy but for hydration. This is deeply intelligent survival physiology at work. - More intense autophagy
Autophagy—the breakdown and recycling of damaged cells — kicks in faster and harder during a dry fast. Without external hydration to buffer toxins, the body becomes hyper-efficient. Damaged proteins, weak cells, and even pathogens are broken down at a much faster rate. - Immune system reset
Studies have shown that fasting, particularly dry fasting, can stimulate the regeneration of white blood cells. It’s a kind of controlled immune reset. Many report improvements in autoimmune symptoms, allergies, and chronic inflammation after repeated short dry fasts. - Rapid fat loss and hormonal recalibration
Dry fasting pushes the body into deeper fat-burning (lipolysis), particularly of visceral fat, which is more inflammatory and metabolically dangerous than subcutaneous fat. Simultaneously, hormones like insulin and leptin recalibrate, improving sensitivity. - Hormetic stress response
Dry fasting is a hormetic stressor—meaning it stresses the body just enough to stimulate healing and adaptation. The result? Improved mitochondrial health, increased resilience, and sharper mental clarity.
But that’s the science. Let me tell you what it actually felt like.
Why the sinus shift?
From a physiological perspective, this wasn’t just a coincidence. Dry fasting creates an internal vacuum of sorts. Without water, the body begins recycling its own fluids—a process that pulls interstitial fluid back into circulation. This shifts osmotic pressure and drains fluid from areas of inflammation, such as the sinuses. This effect is why dry fasting may hold potential for hay fever, chronic sinusitis, and other inflammatory upper respiratory conditions. The immune system, less burdened by digestion and supported by a temporary antimicrobial environment, reboots. Anecdotal reports often describe rapid improvements in allergies and sinus-related symptoms.
In my case, this detoxification process was fast and visceral. The inflammation I had felt just a day before began to visibly subside. My face looked less puffy, and I noticed a deeper, easier breath throughout the day.
What was happening in my body?
The absence of both food and water creates a unique and powerful metabolic storm. The body taps into fat reserves not only for energy but also for water. This process—metabolic or endogenous water production—occurs as triglycerides break down, producing energy, carbon dioxide, and water. It’s how camels and desert animals survive. For humans, it’s an ancient mechanism that supports survival during drought or famine.
Dry fasting also stimulates the production of heat-shock proteins, which protect cells under stress and support cellular repair. This environment encourages autophagy—the recycling of damaged cellular components—and activates the lymphatic system to drain accumulated waste. According to Filonov, these intense internal processes help “burn out” viruses, bacteria, and even abnormal cells more efficiently than during water fasting.
Studies have shown that dry fasting can lead to a rapid decrease in inflammatory markers, a sharper rise in human growth hormone, and a temporary upregulation of stress resilience. It is a metabolic stressor, yes—but one that mimics the evolutionary challenges our ancestors regularly faced.
Comparing water and dry fasting
Let’s break down some of the fundamental differences between the two:
| Feature | Water fasting | Dry fasting |
| Hydration | From water intake | From metabolic processes |
| Autophagy onset | ~18–24 hours | ~10–12 hours |
| Inflammatory load | Gradual reduction | Sharper suppression |
| Sinus clearing | Less noticeable | Rapid due to fluid drainage |
| Microbial effects | Mild detox | Strong antimicrobial action |
| Hormonal shifts | GH↑, insulin↓, cortisol↑ | Same, but more pronounced |
This sharper immune and metabolic response is part of why dry fasting is used therapeutically in Russian clinics for autoimmune and chronic inflammatory conditions. However, Filonov stresses that it must be done with precision, not casually.
Breaking the fast: gentle refeeding
This is where the biggest surprise came in: I didn’t feel amazing right after breaking my fast. Unlike the lightness and mental high I often feel after a 3-day water fast, I felt more like I usually do on day 4 or 5 of a water fast—quiet, fatigued, and inward. My body was clearly still in a deep healing mode.
I broke the fast slowly and intentionally. I started with sipping slowly on warm lemon water and salt, then went on to warm bone broth, followed by melon sprinkled with Celtic salt to replenish electrolytes. Then came soft-boiled eggs and avocado. I felt no urgency to jump back into normal eating. Instead, I honoured the integration process—this phase where the body continues to heal and reorganise, even after the fast ends.
The refeeding phase is often as critical as the fast itself as it’s during this period that stem cell activation, immune recalibration, and tissue repair continue at an accelerated pace. It’s also why I place so much emphasis on refeeding correctly post-fasting with all my clients.
Cautions and considerations
Dry fasting is not for everyone. If you have adrenal fatigue, kidney issues, are on medication, or are under high psychological stress, dry fasting can be too taxing. It’s essential to be metabolically flexible, able to switch between fuel sources like glucose and fat, before attempting a dry fast. The more adapted you are to water, intermittent and prolonged fasting, the easier dry fasting becomes, as the body knows exactly what to do.
If you’re new to fasting, start with intermittent fasting or short water fasts. Train your body gradually. Dry fasting is not a beginner’s tool, it’s an advanced intervention with significant therapeutic potential when done correctly.
I also don’t recommend stacking it with other stressors. Create a calm environment. Rest is absolutely essential. Stay off social media as scrolling is overly stimulating. Let the body do what it was designed to do: adapt and heal.
Final reflections
This wasn’t a spiritual epiphany. It was something deeper, quieter. A rewiring of sorts. I felt a reconnection to the biological intelligence of my body. It reminded me that healing doesn’t always feel “good” or “light” and that no fast is ever the same. Sometimes, it feels like a retreat. Like slowing down. Like stillness.
Dry fasting, when used wisely, offers a sharper, more condensed healing experience than water fasting. It’s known to accelerate healing by 3-5x compared to water fasting, although studies on this are limited. It’s not something to be done casually yet when approached with intention and respect, it’s a powerful tool for recalibration.
I’ll be repeating this practice regularly, but with balance. Emerging research and experiential evidence suggest that weekly 24–36 hour dry fasts may offer more sustainable physiological benefits than prolonged 5-day fasts. Shorter dry fasts allow the body to enter a state of enhanced autophagy, reduce inflammation, and promote cellular repair without placing excessive strain on metabolic reserves. They’re also more adaptable to everyday life, aligning better with hormonal rhythms, stress resilience, and long-term adherence.
That said, I’m currently preparing for a 5-day dry fast in a small support group with three like-minded women. Whether I choose to repeat prolonged dry fasts after this will depend on how my body responds. I’m remaining curious, yet unattached—led by science, by God, and by a deepening awareness of my body’s signals.
Most unexpectedly, I found dry fasting easier than water fasting in some ways. The absence of fluid seemed to quiet hunger more quickly and deepen the sense of stillness in my body. That insight alone has reshaped how I’ll approach fasting from here on out.
This was science-backed. It was spiritually grounding. And it was biologically brilliant.
And for me, it’s just the beginning.