Laureate Institute Float Research: Brain Imaging Studies

Last updated: April 2026

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Consult a qualified healthcare provider before starting any treatment.

Affiliate Disclosure: We may earn a commission when you purchase through our links. This does not affect our editorial independence.

Quick Answer

Float tanks use about 1,000 pounds of Epsom salt (magnesium sulfate) in each commercial tank, creating a buoyant environment for relaxation and potential magnesium absorption.
Magnesium is vital, involved in over 300 biochemical reactions in the body, supporting muscle and nerve function, and regulating blood pressure.
A 2006 pilot study from the University of Birmingham (UK) suggested serum magnesium levels increased after a week of daily Epsom salt baths, though it lacked a control group and peer review.
The global market for float therapy has grown into a multi-billion dollar industry.

Float therapy, also known as flotation therapy or Restricted Environmental Stimulation Therapy (REST), has become a prominent feature in wellness centers and spas worldwide. This practice involves lying in a tank filled with warm water, super-saturated with Epsom salt. The primary appeal of these sensory deprivation tanks is the promise of deep relaxation and the purported health benefits derived from magnesium-rich water. Many float spa enthusiasts believe that soaking in Epsom salt leads to significant magnesium absorption through the skin, which can help with muscle recovery, reduce stress, and improve sleep. Magnesium is an essential mineral, playing a role in over 300 biochemical reactions in the body, including muscle and nerve function, blood pressure regulation, and protein synthesis. The idea that float tanks can replenish magnesium levels, bypassing the digestive system, is particularly appealing given that modern lifestyles, chronic stress, and poor diets often leave many people deficient in this critical mineral. The float therapy market has expanded into a multi-billion dollar global market as people seek natural relief from various ailments.

What is Float Therapy and Why Does Magnesium Matter?

Float therapy offers a unique environment designed for deep relaxation and potential therapeutic benefits. When we talk about float therapy, we are referring to the experience of soaking in a float tank, also known as a sensory deprivation tank or an isolation tank. These tanks are filled with warm water, typically kept at skin temperature, and infused with a massive amount of Epsom salt. A commercial tank often contains around 1,000 pounds of Epsom salt (magnesium sulfate), which creates a highly dense, buoyant saltwater solution. This high density allows a person to float effortlessly on the surface, eliminating the sensation of gravity on joints and muscles. This weightless state, combined with the absence of external stimuli, is designed to create a womb-like environment that promotes profound relaxation.

The Role of Epsom Salt in Float Tanks

Epsom salt, chemically known as magnesium sulfate, is the key ingredient that makes float therapy possible. It is a compound made up of magnesium, sulfur, and oxygen. Beyond its ability to create buoyancy, Epsom salt has been used for centuries for its medicinal qualities. In the context of float tanks, the high concentration of magnesium sulfate is often highlighted as a source for transdermal magnesium absorption. The idea is that the body can absorb magnesium directly through the skin while floating, offering a pathway for this essential mineral to enter the system without passing through the digestive tract. This concept is particularly attractive to those who might have digestive issues or poor nutrient absorption from oral supplements.

Magnesium: An Essential Mineral

Magnesium is far from a low-profile mineral; it is vital for good health and well-being, playing a critical role in numerous bodily functions. It is the second-most abundant element in human cells and the fourth-most important positively charged ion in the body. This mineral is involved in more than 300 biochemical reactions. These reactions are fundamental to supporting muscle and nerve function, regulating blood pressure, aiding in protein synthesis, and even helping with energy production and the elimination of harmful toxins. Magnesium helps to regulate the activity of more than 325 enzymes, underscoring its widespread importance throughout the body.

Addressing Magnesium Deficiency

Modern lifestyles, characterized by chronic stress, consumption of processed foods, and even soil depletion, have made magnesium deficiency a common issue. When magnesium levels are low, individuals can experience a range of symptoms, including muscle cramps, fatigue, insomnia, headaches, and anxiety. The appeal of replenishing magnesium levels by soaking in an Epsom salt float is therefore very strong. It proposes a way to bypass the digestive system and, as the claim goes, deliver magnesium directly through the skin to the muscles and cells that need it. This potential for direct, gentle, and natural support for the body's magnesium levels is a significant reason why many people are drawn to float therapy. The wellness trend of float therapy, driven in part by these perceived benefits, has seen the global market expand into a multi-billion dollar industry as individuals seek natural relief from various ailments.

How Does Transdermal Magnesium Absorption Work?

The concept of absorbing nutrients through the skin, known as transdermal absorption, is a fascinating and appealing idea for many. This method suggests that certain substances can pass directly through the skin barrier and enter the bloodstream or target tissues, completely bypassing the digestive system. For minerals like magnesium, this route is particularly attractive because it could avoid the potential gastrointestinal issues that sometimes accompany oral supplements, such as stomach upset or laxative effects. The skin, while a protective barrier, is not entirely impermeable. It is considered semi-permeable, meaning it allows certain substances to cross it. We see this principle at work with medical patches that deliver nicotine, hormones, or other medications directly through the skin.

The Science of Skin Permeability

The skin's structure, with its multiple layers, presents a complex challenge for nutrient absorption. The outermost layer, the stratum corneum, acts as the primary barrier, designed to keep harmful substances out and essential moisture in. For a substance to be absorbed transdermally, it must be able to penetrate this protective layer. The effectiveness of transdermal absorption depends on several factors, including the size of the molecule, its lipid (fat) solubility, the concentration of the substance, the duration of exposure, and the condition of the skin itself. When it comes to minerals like magnesium, the data on how effectively they pass through the skin is more complex and has been the subject of ongoing research.

Direct Delivery and Steady Uptake

Proponents of transdermal magnesium absorption highlight several potential advantages. One key benefit is the idea of "direct delivery." This means magnesium could be delivered directly to the cells and muscles that need it most, without having to be processed by the liver or interact with other digestive enzymes. This direct pathway is especially appealing for people with gut issues or those who experience poor nutrient absorption when taking supplements orally. Another suggested benefit is "steady uptake." Skin absorption is thought to result in a more controlled and steady uptake of magnesium into the body. This could potentially reduce the risk of the rapid spikes and subsequent drops in magnesium levels that can sometimes occur with oral supplements. A steady uptake could lead to more consistent therapeutic effects and fewer side effects.

Research Insights into Transdermal Absorption

While the concept is appealing, the scientific evidence for significant transdermal magnesium absorption, especially from Epsom salt baths or floats, is still developing. However, some research insights suggest that the idea holds promise. Studies indicate enhanced bioavailability of magnesium when absorbed through the skin. This means that when magnesium is absorbed this way, it might be more readily available for the body to use compared to some oral forms. The warm, buoyant environment of a float tank is thought to facilitate this absorption. The warmth of the water can open pores and increase blood flow to the skin, potentially making it more receptive to mineral uptake. The extended period of immersion in a highly concentrated magnesium sulfate solution is also considered an optimal environment for absorption. While the exact mechanisms and quantities absorbed are still being investigated, the potential for transdermal magnesium absorption remains a key selling point for float therapy. The unique environment of a float tank is designed to maximize this potential, offering a different route for the body to access this essential mineral.

What Does the Research Say About Magnesium Absorption in Float Tanks?

The question of whether magnesium truly absorbs through the skin in meaningful amounts during a float session is central to understanding the full benefits of float therapy. While anecdotal evidence from float spa enthusiasts is abundant, scientific research aims to provide concrete answers. We look to peer-reviewed studies, expert opinions, and float industry perspectives to get a clearer picture.

Early Studies and Their Limitations

A few small studies have suggested that magnesium levels in the body can rise after soaking in Epsom salts. One frequently cited pilot study was conducted in 2006 at the University of Birmingham (UK). This study claimed that serum magnesium levels increased after a week of daily Epsom salt baths. The findings were interesting, indicating a potential for transdermal absorption. However, it is crucial to understand the limitations of this particular study. It lacked a control group, which is a standard component of robust scientific research designed to compare outcomes between a treatment group and a group that does not receive the treatment. Without a control group, it is difficult to definitively attribute any observed changes solely to the Epsom salt baths. Furthermore, this pilot study was never peer-reviewed. Peer review is a critical process in scientific publishing where other experts in the field evaluate the methodology, results, and conclusions of a study to ensure its rigor and validity. Because of these limitations, the findings of the 2006 University of Birmingham study, while intriguing, are far from definitive. They serve as a starting point for further investigation rather than conclusive proof.

Emerging Evidence and Muscle Relaxation

Despite the early limitations, the idea of transdermal magnesium absorption continues to attract scientific interest. Other studies indicate that transdermal magnesium application can reduce muscle stiffness. This specific benefit is often highlighted by those who use float tanks for muscle recovery and tension relief. Magnesium plays a role in muscle relaxation, so the idea that applying it directly to the skin could help alleviate muscle tension and soreness is consistent with its known physiological functions. While these studies might not always focus specifically on float tanks, they contribute to the broader understanding of how magnesium can interact with the body through the skin. The warm, buoyant environment of a float tank, with its high concentration of magnesium sulfate, is considered an optimal setting for this potential absorption. The Remarkable Health Benefits of Transdermal Magnesium Absorption in Sensory Deprivation Float Tanks highlights how the warm environment facilitates magnesium absorption.

Comparing Absorption Methods

When considering magnesium absorption, it is important to compare float tanks to other methods, such as oral supplements or magnesium "oil" sprays. Oral supplementation is a common route, but it can be associated with gastrointestinal issues for some individuals. Transdermal methods, including float therapy, are appealing because they bypass the digestive system entirely. However, the exact amount of magnesium absorbed through the skin, and whether it is sufficient to correct a significant deficiency, remains a topic requiring more comprehensive, peer-reviewed research. The appeal of float therapy extends beyond just magnesium absorption. It is also valued for its profound calming effects on the nervous system, which can contribute to stress reduction and improved sleep, regardless of the amount of magnesium absorbed. The sensory deprivation aspect itself is a powerful tool for relaxation. While the science of transdermal magnesium absorption in float tanks is still evolving, the existing research suggests a plausible, albeit not fully quantified, benefit. The 2006 pilot study from the University of Birmingham (UK) is an example of research that opened the door to further inquiry, even with its methodological limitations. Our analysis of the available data suggests that while the definitive "medicine" verdict requires more robust studies, the "myth" aspect is steadily being challenged by ongoing exploration into the science of skin and magnesium.

Why Are Epsom Salts Used in Float Tanks?

Epsom salts are fundamental to the float therapy experience, serving multiple critical functions that make the practice both effective and unique. Their use is not arbitrary but rooted in their chemical composition and long history of medicinal application. Understanding why these specific salts are chosen helps clarify the science behind float tanks.

The Chemical Composition of Epsom Salt

Epsom salt is chemically known as magnesium sulfate, with the formula MgSO4·7H2O. This compound is made up of three key elements: magnesium, sulfur, and oxygen. Each of these components contributes to the properties that make Epsom salt ideal for float tanks. Magnesium, as we have discussed, is a vital mineral for numerous bodily functions. Sulfur and oxygen, while often less emphasized in the context of float therapy benefits, are also important elements. The specific crystalline structure of magnesium sulfate heptahydrate (MgSO4·7H2O) allows it to dissolve readily in water, creating the highly concentrated solution necessary for buoyancy. This chemical makeup is what gives Epsom salt its distinctive characteristics, differentiating it from common table salt (sodium chloride). Why floatation tanks use Epsom salts explains this chemical composition in detail.

Providing Buoyancy: The Primary Role

The primary reason Epsom salts are used in float tanks is to create extreme buoyancy. A typical float tank contains a super-saturated mixture of Epsom salts and water. This means the water holds much more dissolved salt than it normally would, significantly increasing its density. When a person lies in this dense solution, they float effortlessly on top of the skin-temperature water. This sensation of weightlessness is crucial to the float therapy experience. It removes the constant gravitational pressure on the body, allowing muscles to fully relax and the spine to decompress. This reduction in gravity is a key factor in achieving deep physical and mental relaxation, making float tanks an excellent way of combating stress, alleviating muscular aches and pains, and for reaching Zen-like states of relaxation. Without the immense buoyancy provided by Epsom salts, the experience would be more akin to a regular bath, lacking the unique sensory deprivation and weightless aspects that define float therapy.

Historical and Medicinal Qualities

Epsom salt has a long history of use for its medicinal qualities, dating back centuries. It was traditionally used in baths for various ailments, including muscle soreness, skin conditions, and detoxification. This historical context informs its continued use in wellness practices like float therapy. The belief in its therapeutic properties has been passed down through generations, and modern science is now exploring the mechanisms behind these traditional claims. While some traditional uses may lack rigorous scientific validation, the sustained popularity of Epsom salt suggests a perceived benefit by users.

Magnesium: The Core Mineral

Beyond buoyancy, the magnesium content of Epsom salt is a significant selling point for float therapy. Magnesium is the second-most abundant element in human cells and the fourth-most important positively charged ion in the body. It is involved in over 300 biochemical reactions, from muscle control and electrical impulses to energy production and the elimination of harmful toxins. This low-profile mineral is vital to good health and well-being. Magnesium helps to regulate the activity of more than 325 enzymes, highlighting its widespread importance. The idea that soaking in an Epsom salt solution could allow the body to absorb this essential mineral through the skin is a major draw. It offers a potential pathway to replenish magnesium stores, which many people find appealing given the widespread issue of magnesium deficiency in modern society. The combination of incredible buoyancy and the potential for magnesium absorption makes Epsom salts indispensable to the float tank experience.

Beyond Magnesium: Other Benefits of Float Therapy

While the potential for transdermal magnesium absorption is a significant aspect of float therapy, the benefits extend far beyond just mineral replenishment. The unique environment of a sensory deprivation tank itself offers a powerful array of advantages for both physical and mental well-being. Float therapy creates conditions that promote profound relaxation, stress reduction, and physical recovery, making it a holistic wellness tool.

Calming the Nervous System

One of the most widely recognized benefits of float therapy is its calming effect on the nervous system. As you rest weightlessly in the warm, quiet, and dark environment of a float tank, your body enters a state of deep relaxation. This sensory deprivation, or Restricted Environmental Stimulation Therapy (REST), minimizes external stimuli such as light, sound, and touch. This reduction in sensory input allows the brain to slow down, shifting from an active, alert state to a more meditative or theta-wave state. This shift can lead to a decrease in stress hormones like cortisol and an increase in beneficial neurochemicals. The profound quiet and darkness allow the mind to disengage from the constant barrage of information it typically processes, fostering a sense of peace and tranquility. Many individuals report feeling a deep sense of calm and mental clarity after a float session, describing it as a reset for their nervous system.

Alleviating Muscle Tension and Soreness

The physical benefits of float therapy are also substantial, particularly for muscular relaxation. The highly buoyant Epsom salt solution allows the body to float effortlessly, effectively eliminating the effects of gravity on joints and muscles. This weightless state provides a unique opportunity for the muscles to fully release tension that they might unconsciously hold throughout the day. Without the need to constantly fight gravity, the spine elongates, and compressed joints can decompress. This physical release, combined with the warmth of the water, helps to alleviate muscle tension and soreness. Athletes often use float therapy for faster recovery after intense workouts, noting a reduction in muscle stiffness. Even for individuals experiencing chronic pain or general muscle tightness, the float tank offers a gentle yet powerful way to find relief. The magnesium in the Epsom salt, whether absorbed transdermally or not, is known to play a role in muscle relaxation, further contributing to this benefit.

Stimulating Lymph Drainage

Soaking in Epsom salts has been found to stimulate lymph drainage. The lymphatic system is a crucial part of the body's immune system, responsible for removing waste products, toxins, and excess fluid from tissues. Lymph drainage is essential for maintaining fluid balance and supporting immune function. While the exact mechanism by which Epsom salt baths stimulate this process is still being explored, the warm water and the mineral content may contribute to improved circulation and detoxification. This can lead to a feeling of lightness and reduced bloating after a float session, as the body works more efficiently to clear out metabolic waste.

Stress Reduction and Mental Well-being

Float tanks are an excellent way of combating stress and for reaching Zen-like states of relaxation. The combination of sensory deprivation and physical weightlessness creates an environment conducive to deep meditative states. In this state, individuals often experience reduced anxiety, improved mood, and enhanced mental clarity. Many users report feeling more centered, calm, and resilient to daily stressors after regular float sessions. The ability to disconnect from external distractions and turn inwards can also foster introspection and self-awareness, contributing to overall mental well-being. For those seeking natural relief from the pressures of modern life, float therapy offers a powerful sanctuary. It is a space where the mind can quiet, the body can heal, and a profound sense of peace can be cultivated. Magnesium Absorption in Float Tanks: Myth or Medicine? touches on the broader benefits beyond just magnesium uptake.

Who Invented the Float Tank?

The invention of the float tank, originally known as the isolation tank, is credited to a remarkable individual whose career spanned diverse scientific and philosophical fields. His work pushed boundaries and challenged conventional thinking about the mind and consciousness.

John C. Lilly: The Pioneer

The isolation tank was developed by John C. Lilly, an American physician, scientist, psychonaut, and philosopher. Born on January 6, 1915, and passing away on September 30, 2001, Lilly dedicated his life to exploring what he believed was the limitless potential of the mind. His career was characterized by a relentless curiosity and a willingness to venture into unconventional areas of research. He was a neuroscientist, psychoanalyst, writer, and inventor, often praised as a pioneer by the scientific and medical community, but at times also ostracized as an eccentric due to his more controversial explorations.

Development of the Isolation Tank

Lilly's initial work on the isolation tank began in the mid-1950s. His goal was to understand the origins of consciousness and the brain's activity in the absence of external stimuli. He wanted to create an environment where the brain could be completely cut off from all sensory input, allowing him to study its intrinsic activity. This led to the development of the first isolation tank, a dark, soundproof chamber filled with salt water, designed to create a state of complete sensory deprivation. Lilly himself frequently used the tank, experiencing profound shifts in consciousness and perception. His early experiments laid the groundwork for what would eventually become modern float therapy.

Exploration of Human Consciousness

Lilly's work with the isolation tank was part of his broader exploration of human consciousness. He was deeply interested in the nature of the mind and its capabilities when freed from external distractions. He believed that by removing sensory input, individuals could access deeper states of awareness and unlock hidden potentials of the brain. His research in this area was groundbreaking, offering new insights into the effects of sensory deprivation on the human psyche. Beyond the float tank, Lilly also explored other avenues for expanding consciousness, including his controversial experiments with psychedelics and interspecies communication. He was known for his work attempting to communicate with dolphins, which further highlighted his unconventional approach to science and his belief in the interconnectedness of all life. His adventures with dolphins, drugs, and aliens further illustrate his unique path in science. John C. Lilly provides an overview of his diverse career.

A Legacy of Innovation

John C. Lilly's legacy is complex and multifaceted. He was a brilliant scientist who made significant contributions to neuroscience and biophysics, yet he also embraced ideas that were often considered outside the mainstream. His development of the isolation tank, however, remains one of his most enduring and widely accepted contributions. The float tanks used in wellness centers today are direct descendants of his original invention. They continue to provide a unique environment for relaxation, introspection, and the exploration of consciousness, fulfilling some of Lilly's original intentions. His life, spanning from January 6, 1915, until September 30, 2001, was a testament to intellectual courage and an unyielding quest for understanding the mind's capabilities. John C. Lilly: The pioneer of floating details his pioneering role in floatation.

Frequently Asked Questions

Is magnesium absorption through the skin in a float tank a proven fact?

The direct absorption of magnesium through the skin in float tanks is a topic of ongoing scientific discussion. While some small studies, such as a 2006 pilot study from the University of Birmingham (UK), have suggested that serum magnesium levels can increase after Epsom salt baths, this particular study lacked a control group and was not peer-reviewed, meaning its findings are not definitive. Other research indicates that transdermal magnesium application can help reduce muscle stiffness. The concept is appealing, but more robust, peer-reviewed studies are needed to fully prove and quantify the extent of magnesium absorption in float tanks.

How much Epsom salt is typically used in a float tank?

Float tanks are designed to create a highly buoyant environment, which requires a significant amount of Epsom salt. A commercial float tank often contains around 1,000 pounds of Epsom salt (magnesium sulfate). This high concentration of salt increases the density of the water, allowing individuals to float effortlessly on the surface. This super-saturated solution is what makes the weightless experience of float therapy possible.

What are the main health benefits of magnesium?

Magnesium is an essential mineral that plays a crucial role in maintaining overall health. It is involved in over 300 biochemical reactions in the body. Key benefits include supporting muscle and nerve function, regulating blood pressure, aiding in protein synthesis, and contributing to energy production. Magnesium also helps to regulate the activity of more than 325 enzymes. Deficiencies can lead to issues like muscle cramps, fatigue, insomnia, and anxiety.

Can float therapy help with muscle recovery?

Yes, float therapy is widely used for muscle recovery and tension relief. The weightless environment created by the high concentration of Epsom salt in the water allows muscles to fully relax and decompress, free from the constant pull of gravity. This helps alleviate muscle tension and soreness. The magnesium itself, whether absorbed through the skin or not, is known to be involved in muscle relaxation, further contributing to this benefit. Many athletes find float therapy beneficial for reducing stiffness and speeding up post-workout recovery.

Who was John C. Lilly and what was his role in float tank development?

John C. Lilly was an American physician, neuroscientist, psychonaut, and philosopher who invented the isolation tank in the mid-1950s. His primary goal was to study the brain's activity in the complete absence of external sensory input, exploring the origins of consciousness. Lilly's work laid the foundation for modern float therapy. He lived from January 6, 1915, to September 30, 2001, and was known for his groundbreaking, sometimes controversial, research into human consciousness and interspecies communication.