Float Therapy: What the Research Actually Shows

Almost everything we call rest still asks something of us. A quiet evening still has a screen in it. A holiday still has a schedule. Even meditation, for most people, is a practice you have to work at — a thing you do rather than a thing you receive.

Floating is unusual in that it asks for nothing at all.

You lie back in shallow water so dense with Epsom salt that you cannot sink. The water is held at skin temperature, so the line where your body ends and the water begins gradually stops being obvious. The lid closes, or the light goes out, and the ordinary work of being a person in a room — holding yourself upright, tracking sounds, adjusting to light, feeling the weight of your own limbs — simply stops being necessary.

What's left is remarkably little. And that, it turns out, is the point.

Researchers call it Floatation-REST — Reduced Environmental Stimulation Therapy — and unlike most things in the wellness category, it began in a laboratory rather than a spa. Over the past decade, clinical psychologists and neuroscientists have run it as a genuine intervention: in people with severe anxiety, in patients hospitalised with anorexia nervosa, in people living with chronic pain.

The findings are more interesting than the marketing. They're also more limited than the marketing. At Aureline Wellness, we'd rather give you both. Every study referenced below is linked to its listing on PubMed, the U.S. National Library of Medicine's index of biomedical literature, so you can read the source yourself.

Research Snapshot

Research suggests floating may support several aspects of wellbeing, though the strength of the evidence varies considerably by outcome — and one popular claim doesn't survive contact with the evidence at all.

What Floating Actually Is

A floatation tank holds about 25–30 cm of water carrying several hundred kilograms of dissolved Epsom salt (magnesium sulfate). That density makes the water far more buoyant than the sea — you float on the surface without any effort, without treading, without thinking about it.

The water and air are held near skin temperature, around 34–35°C. Sound is largely removed. Light can be removed entirely. As the researchers who study it describe the setup, the float experience is calibrated so that signals from the visual, auditory, olfactory, thermal, tactile, vestibular, gravitational and proprioceptive channels are all minimised at once (PubMed).

That's the whole intervention. Not adding something — subtracting nearly everything.

Anxiety: The Strongest Finding, and It's a Big One

The landmark study came out of the Laureate Institute for Brain Research in Tulsa. Feinstein and colleagues, publishing in PLoS One in 2018, recruited 50 participants across a spectrum of anxiety and stress-related disorders — post-traumatic stress, generalised anxiety, panic, agoraphobia, social anxiety — and 46 of them also had comorbid depression (PubMed).

After a single one-hour float, state anxiety fell with an estimated Cohen's d greater than 2. For context, that is a very large effect by the conventions of psychology research, where 0.8 is already considered large. Participants also reported significant reductions in stress, muscle tension, pain, depression and negative affect, alongside increases in serenity, relaxation and happiness (p < 0.0001 across the board).

The most striking detail: the most severely anxious participants reported the largest effects, and their post-float scores approached those of non-anxious controls.

Now the caveats, which the authors state plainly. This was an open-label study — no control condition, participants knew what they were getting. It measured a single session. And the effect was described as transient. The authors' own conclusion is that floating "may be a promising technique for transiently reducing the suffering in those with anxiety and depression," and that the findings "need to be replicated in larger controlled trials."

A companion study did add a control. Feinstein and colleagues, writing in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, ran a within-subject crossover design in which 31 people with high anxiety sensitivity underwent either a 90-minute float or a comparison condition (PubMed). Against the comparison, floating produced significant reductions in state anxiety and muscle tension and increases in relaxation and serenity (p < 0.001). They also measured blood pressure throughout, and found reductions during the session averaging more than 12 mmHg at the diastolic low point.

Anorexia Nervosa: The Best-Designed Trial in the Field

The most rigorous float study to date is also the most unexpected. Choquette and colleagues published a randomised clinical efficacy trial in EClinicalMedicine in 2023, testing floatation-REST in women and girls hospitalised for anorexia nervosa — a condition with one of the highest mortality rates in psychiatry (PubMed).

Sixty-eight inpatients were randomised to eight twice-weekly 60-minute float sessions plus usual care, or usual care alone. The float group showed significant acute reductions in body dissatisfaction (p = 0.00026) and in state anxiety (p < 0.0001, Cohen's d = 1.52). The care-as-usual group showed no significant change.

We include this not because we think anyone should buy a float tank to treat an eating disorder — you shouldn't, and this was inpatient care in a hospital — but because it tells you something about the seriousness of the research. This is a preregistered, randomised, intention-to-treat trial in a severely ill clinical population. That's a long way from spa marketing.

Chronic Pain and Stress: Consistent, Small, Encouraging

Stuart and colleagues published a scoping review in the Journal of Pain Research in 2026, gathering every study of flotation-REST for chronic pain: eight studies, of which six were randomised controlled trials, totalling 401 participants (PubMed).

Their summary: studies consistently reported improvements in pain intensity and frequency, fewer pain locations, and greater pain tolerance. Anxiety and depression were substantially reduced in most studies. Stress consistently declined and optimism increased. Sleep improved in some studies and not others. Physiological and biomarker findings were variable — though they did note a post-treatment reduction in MHPG, a norepinephrine metabolite, consistent with reduced sympathetic arousal.

Their verdict is worth quoting: floating "appears promising for reducing chronic pain and enhancing psychological well-being," while "high-quality randomized trials with standardized interventions and longitudinal follow-up are needed to confirm efficacy." They couldn't even run a meta-analysis, because the studies varied too much to pool.

Two older Swedish trials fill in the picture. Kjellgren and Westman randomised 65 healthy participants to twelve float sessions over seven weeks or a wait-list, publishing in BMC Complementary and Alternative Medicine in 2014: stress, depression, anxiety and worst pain all fell significantly in the float group, while optimism and sleep quality rose. The control group showed no significant change (PubMed). And Bood and colleagues, in Pain Research & Management in 2009, found that 88 patients with chronic stress-related muscle tension pain improved on stress, anxiety, depression, sleep quality and pain — and measurably increased their tolerance of experimentally induced pain (PubMed).

That 2014 trial matters most for readers of this page, because it's the one that studied people who weren't ill.

Generalised Anxiety Disorder

Jonsson and Kjellgren ran a randomised controlled pilot trial in BMC Complementary and Alternative Medicine in 2016, allocating 46 people with generalised anxiety disorder to twelve float sessions or a waiting list (PubMed).

GAD symptoms fell significantly in the treatment group, and 37% reached full remission by the end of treatment. Benefits were also seen for sleep difficulties, emotional regulation and depression, and most gains held at six-month follow-up. No negative effects were found. The treatment had ambiguous or no effect on pathological worry.

The authors are careful, and so are we: participants were self-diagnosed via self-report measures, the control was a waiting list rather than an active comparison, and they position floating as "a complementary treatment alongside existing treatment," not a replacement for it.

Sleep: Genuinely Thin

If you're buying a float tank to fix your sleep, you should know exactly what the evidence is.

The only study to look at flotation-REST specifically as an insomnia treatment, by Norell-Clarke and colleagues in Sleep Science in 2022, had six participants (PubMed). Three improved on their main insomnia symptom. Two improved on sleep efficiency. Two didn't improve on any sleep measure at all. Total sleep time didn't change for anyone. The authors describe the results as "mixed" and suggest floating "may be beneficial for young adults with sleep-onset insomnia" — noting the two who benefited most were students in their twenties.

Six people is a case series, not evidence of efficacy. Sleep improvements do show up as a secondary outcome in several of the larger trials above, which is encouraging. But nobody has yet demonstrated that floating reliably fixes sleep.

The Magnesium Claim Doesn't Hold Up

This one deserves its own section, because you will read it on almost every float website in the world: that floating delivers magnesium into your body through the skin, from all that dissolved Epsom salt.

In 2026, researchers at the University of Copenhagen tested it directly. Camili and colleagues, publishing in the European Journal of Pharmaceutics and Biopharmaceutics, measured magnesium permeation from a saturated magnesium sulfate solution across skin using mass spectrometry (PubMed).

Across intact skin, permeation was minimal — and crucially, there was no significant difference between the magnesium-treated samples and the untreated controls. Their conclusion: "transdermal magnesium delivery from simple aqueous solutions is unlikely under normal physiological conditions."

Permeation rose by orders of magnitude when the skin barrier was deliberately stripped away — which tells you the stratum corneum is doing its job, and is not an argument for floating.

So the salt in a float tank is there to make you buoyant. That's a genuinely important job, and it's the entire reason the experience works. It just isn't a mineral supplement, and we're not going to pretend otherwise.

What the Evidence Does Not Support

To be direct about the claims we won't make:

• Magnesium absorption. Directly measured, and not meaningfully occurring through intact skin.
• Detoxification. No good evidence supports it. Your liver and kidneys do that work.
• Guaranteed better sleep. The one dedicated insomnia study had six participants and mixed results.
• Lasting relief from a single session. The large anxiety effects measured so far are explicitly described as transient.
• Proven long-term clinical efficacy. The largest recent trial tested whether repeated floating is feasible and safe — not whether it works over time. The authors call for larger efficacy trials, and those haven't been run yet.
• A replacement for treatment. Every research group in this field positions floating as complementary to care, never as a substitute for it.

How Good Is the Evidence Overall?

Honestly? Small, young, and better designed than you'd expect.

The largest recent trial — Garland and colleagues in PLoS One, 2024 — randomised 75 anxious and depressed individuals to six float sessions in various formats or an active comparator (a zero-gravity chair) (PubMed). Adherence ran 85–89% for floating, there were no serious adverse events, and positive experiences were reported more often, and more intensely, than negative ones.

But read the title carefully: it's a safety and feasibility trial. It was designed to establish that people will actually do this and won't come to harm — not to prove it treats anything. The authors say so: "Larger randomized controlled trials evaluating markers of clinical efficacy are warranted."

That sentence is the honest summary of this entire field. Floating is consistently safe, consistently pleasant, and produces large short-term reductions in anxiety that have now been measured by several independent groups. Whether those effects accumulate into lasting change is a question the research has not yet answered. A great deal of the work also comes from two research groups — one in Tulsa, one in Sweden — which is a real limitation.

Compare that with sauna research, where a 2018 review found only 13 of 40 studies were randomised trials. The float literature is much smaller, but proportionally better controlled. It's early, not flimsy.

What a Float Actually Feels Like

Most first-timers expect boredom or claustrophobia. What the research finds is closer to the opposite.

The first ten minutes are usually the fidgety part — finding a position for your arms, noticing every small sound, wondering whether you're doing it right. Then the water stops registering as water. Because the temperature matches your skin and the salt removes the effort of staying afloat, your nervous system gradually loses track of where you end.

The Feinstein crossover study found something specific here: as external sensation dropped away, participants became more aware of internal sensation — heartbeat, breath — and their attention to those signals increased significantly. The researchers connect this to why floating calms people who are ordinarily frightened by their own bodily sensations: in the absence of everything else, attention settles on the breath, and the feared signals turn out to be survivable.

It's a strange thing to read in a journal and recognise from experience. The tank isn't doing anything to you. It's removing everything that was doing something to you.

You can also leave the lid open, keep a light on, or step out at any moment. The door doesn't lock. That reassurance matters more to most people than any study.

Safety and Practicalities

Across all the trials above, including one in a severely ill inpatient population, no serious adverse events were reported. Floating is about as low-risk as an intervention gets. A few sensible notes:

• Cuts sting. Salt-saturated water finds every shaving nick. Cover small cuts with petroleum jelly, or shave another day.
• Keep the salt out of your eyes. It's unpleasant rather than dangerous. Keep a fresh-water spray bottle and a towel within reach.
• Don't float on a full stomach, or a rumbling empty one. A light meal an hour or two before is the usual advice.
• Skip alcohol beforehand — the same rule that applies to sauna and cold plunge applies here.
• Water care is not optional. A home tank means filtration, sanitiser and regular testing. It's the least glamorous part of ownership and the part that determines whether you use it in year three.
• Talk to your doctor first if you are pregnant, have epilepsy, kidney disease, open wounds or a skin infection, low blood pressure, or a psychotic disorder. The blood-pressure drop measured during floating averaged over 12 mmHg diastolic, which is worth knowing if yours already runs low.

How to Use One, Based on the Studies

The protocols that produced results are consistent enough to copy:

• Session length. 60 minutes in most trials; 90 in the crossover study; 45 in the insomnia work. An hour is the standard for good reason.
• Frequency. The Swedish trials used twelve sessions over about seven weeks. The anorexia trial used eight sessions over four weeks. Roughly twice a week.
• Course length. Four to seven weeks before judging it. Single sessions produce real but transient effects; the durable outcomes in these studies came from repeated floats.
• Expect the first one to be the worst one. Learning to stop steering takes a session or two.
• Consistency over duration. As with every modality we sell, the research rewards showing up, not heroics.

Choosing a Float Tank

Floating is the most demanding home wellness purchase in terms of space, water care and commitment — and the one with the least competition for your attention once you're inside it. Across our Dreampod range:

• Dreampod Home Float Pro — the most accessible way into home floating, built for one.
• Dreampod Home Float Plus — the Home Float with upgraded filtration and finish.
• Dreampod Sport — built with recovery-focused users in mind.
• Dreampod V2 Flagship — the full commercial-grade sensory isolation experience.
• Dreampod VMAX — the largest pod in the range, for the most complete isolation.

Browse the full float therapy collection to compare sizes, filtration and footprints. Our buying guides cover the practical questions — room requirements, humidity, drainage and power — that decide whether a tank fits your home before it fits your routine.

If floating appeals but the commitment doesn't yet, the same nervous-system logic sits behind our saunas and cold plunges — and our evidence review of infrared saunas takes the same honest look at that literature.

Frequently Asked Questions

Does floating actually reduce anxiety?

The short-term evidence is the strongest in this field. A 2018 study in PLoS One found a single one-hour float substantially reduced state anxiety across 50 people with anxiety and stress-related disorders, with a very large effect size, and the most anxious participants improved most. A controlled crossover study found the same effect against a comparison condition. The important caveat is that these effects are described as transient, and long-term efficacy hasn't been established.

Do you absorb magnesium from the Epsom salt?

No — this is the most common float claim and the evidence doesn't support it. A 2026 study in the European Journal of Pharmaceutics and Biopharmaceutics measured magnesium permeation across intact skin directly and found no significant difference from untreated controls, concluding transdermal magnesium delivery from aqueous solutions is unlikely under normal conditions. The salt is there to make you float, which is reason enough.

Will floating help me sleep?

Possibly, but it isn't demonstrated. The only dedicated insomnia study had six participants, and results were mixed — three improved on their main symptom, two improved on none. Sleep does improve as a secondary outcome in several larger trials, so the signal isn't absent; it just hasn't been properly tested.

How often should I float?

The trials that produced lasting improvements used roughly two sessions a week over four to seven weeks — typically twelve sessions in the Swedish studies, eight in the anorexia trial. Sessions were usually 60 minutes. A single float produces real effects, but the research suggests they fade.

Is floating safe?

Very. Across every trial reviewed here — including a randomised trial in hospitalised patients and a 75-person feasibility trial — no serious adverse events were reported. Take normal precautions: cover cuts, keep salt out of your eyes, avoid alcohol beforehand, and talk to your doctor first if you're pregnant or have epilepsy, kidney disease, low blood pressure, skin infections, or a psychotic disorder.

Is it claustrophobic?

It's the most common worry and the least common experience. You control the lid and the lights, you can leave whenever you want, and nothing is closed or locked. Many people float with the lid open, at least at first. In the 2024 feasibility trial, adherence to repeated floating ran 85–89%, and participants reported positive experiences more often and more intensely than negative ones.

How is floating different from meditation?

Meditation asks you to direct your attention. Floating removes most of what your attention would otherwise be doing. Interestingly, research found that as external sensation dropped away, participants became significantly more aware of internal sensations like heartbeat and breath — which may be part of why it calms people who usually find their own bodily sensations distressing.

References

1. Feinstein JS, Khalsa SS, Yeh HW, et al. Examining the short-term anxiolytic and antidepressant effect of Floatation-REST. PLoS One. 2018;13(2):e0190292. PubMed
2. Feinstein JS, Khalsa SS, Yeh H, et al. The Elicitation of Relaxation and Interoceptive Awareness Using Floatation Therapy in Individuals With High Anxiety Sensitivity. Biological Psychiatry: Cognitive Neuroscience and Neuroimaging. 2018;3(6):555–562. PubMed
3. Choquette EM, Flux MC, Moseman SE, et al. The impact of floatation therapy on body image and anxiety in anorexia nervosa: a randomised clinical efficacy trial. EClinicalMedicine. 2023;64:102173. PubMed
4. Garland MM, Wilson R, Thompson WK, et al. A randomized controlled safety and feasibility trial of floatation-REST in anxious and depressed individuals. PLoS One. 2024;19(6):e0286899. PubMed
5. Stuart SJ, Achury LK, Kline M, Bair MJ. A Scoping Review of Flotation-REST (Restricted Environmental Stimulation Therapy) for Chronic Pain and Associated Comorbidities. Journal of Pain Research. 2026;19:565238. PubMed
6. Jonsson K, Kjellgren A. Promising effects of treatment with flotation-REST as an intervention for generalized anxiety disorder (GAD): a randomized controlled pilot trial. BMC Complementary and Alternative Medicine. 2016;16:108. PubMed
7. Kjellgren A, Westman J. Beneficial effects of treatment with sensory isolation in flotation-tank as a preventive health-care intervention – a randomized controlled pilot trial. BMC Complementary and Alternative Medicine. 2014;14:417. PubMed
8. Bood SA, Kjellgren A, Norlander T. Treating stress-related pain with the flotation restricted environmental stimulation technique: are there differences between women and men? Pain Research & Management. 2009;14(4):293–298. PubMed
9. Norell-Clarke A, Jonsson K, Blomquist A, Ahlzén R, Kjellgren A. A study of flotation-REST as an insomnia treatment. Sleep Science. 2022;15(Spec 2):361–368. PubMed
10. Camili V, Stürup S, Heinz A. Does magnesium permeate the skin? An ex vivo investigation of magnesium ion delivery through intact and barrier-disrupted skin. European Journal of Pharmaceutics and Biopharmaceutics. 2026;226:115173. PubMed
11. Flux MC, Fine TH, Poplin T, et al. Exploring the acute cardiovascular effects of Floatation-REST. Frontiers in Neuroscience. 2022;16:995594. PubMed
12. Hussain J, Cohen M. Clinical Effects of Regular Dry Sauna Bathing: A Systematic Review. Evidence-Based Complementary and Alternative Medicine. 2018;2018:1857413. PubMed

This article is for general educational purposes and is not medical advice. It summarises published research, including its limitations, and should not be used to diagnose or treat any condition. Floatation-REST has been studied as a complement to clinical care, never as a replacement for it. If you are living with anxiety, depression, an eating disorder, or chronic pain, please speak to your physician — and talk to them before floating if you are pregnant or have epilepsy, kidney disease, low blood pressure, or a skin infection.

Related reading: Infrared Sauna Benefits: What the Research Shows · Why Recovery Is the New Luxury · Shop Float Therapy