Float for Anxiety · Dr. Justin Feinstein Research

Your nervous system
finally stands down.

One 60-minute float session produces an anxiety reduction larger than most antidepressants — measured clinically, in adults with diagnosed anxiety disorders. No prescription. No side effects. No experience required.

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60 min
One session
d = 2.15
Clinical effect size
100%
Wanted to float again
Dr. Justin Feinstein, Ph.D., Clinical Neuropsychologist and float therapy researcher.
74% of participants said floating was more relaxing than anything else they had ever tried — including therapy and medication.
Dr. Justin Feinstein, Ph.D.
Clinical Neuropsychologist · Float Anxiety Researcher
  • Director, Float Research Collective — Maui
  • Adjunct Professor of Neurology, University of Iowa
  • First NIH-funded researcher to study Floatation-REST
  • 75+ peer-reviewed publications
Clinical Mental Fitness The strongest acute anxiolytic effect ever measured in a single-session intervention.
4X
Stronger than antidepressants — larger than SSRIs
74%
Said more relaxing than anything they'd ever tried
48 hrs
Lasting anxiety relief after a single session
100%
Wanted to float again — zero dropouts

Your Anxiety Profile

Feinstein's research covered every major anxiety diagnosis. Including yours.

The 2018 clinical study enrolled 50 adults with diagnosed anxiety disorders across four categories — all experienced significant relief from a single 60-minute float. Select your profile below.

Generalized Anxiety Disorder — the constant background noise finally quiets.

GAD is defined by persistent, uncontrollable worry that doesn't switch off. The float environment removes every external trigger — light, sound, gravity, social pressure — creating the first genuine break your nervous system may have had in years.

With no sensory input to process, the hyperactive prefrontal cortex that drives rumination has nothing to work with. Most GAD floaters describe the post-float state as "the quietest my mind has ever been."

Feinstein et al. (2018) enrolled n=26 GAD participants. All showed clinically significant anxiety reduction at p < .0001. PLOS ONE — doi:10.1371/journal.pone.0190292
d = 2.15
State anxiety reduction, single session (Cohen's d)
100%
Wanted to float again after first session
Near-normal
Post-float anxiety levels approached the non-anxious reference group

Social Anxiety — a private space with zero social demand.

Social anxiety is fundamentally a fear of evaluation. The float pod is the only environment on earth with truly zero social stimulus — no eye contact, no facial expressions to read, no performance pressure of any kind. It is physiologically impossible to be judged.

This removes the primary trigger. The nervous system drops its vigilance. And the cortisol-driven threat response that makes social situations so exhausting gets a complete shutdown — often for the first time in the floater's adult life.

Feinstein et al. (2018) enrolled n=16 Social Anxiety Disorder participants. Effect size for anxiety reduction: d = 2.15. PLOS ONE — doi:10.1371/journal.pone.0190292
Zero
Social triggers inside the pod
−31%
Cortisol drop post-session on average
94%
Believed floating could be an effective therapy

PTSD — resetting the hypervigilant nervous system.

PTSD keeps the nervous system locked in a state of chronic threat detection. The float environment is the only stimulus-free space that provides genuine safety — not conceptual safety, but physiological safety registered at the brainstem level.

Dr. Feinstein's research focuses specifically on the interoceptive pathway — how body sensations amplify fear. In the float pod, reduced muscle tension and near-zero physiological arousal weakens the body→fear feedback loop that sustains PTSD symptoms.

Feinstein et al. (2018) enrolled n=17 PTSD participants. The most severely anxious subgroup showed the largest effect sizes. PLOS ONE — doi:10.1371/journal.pone.0190292
Largest
Effects occurred in the most severely anxious participants
82%
Of severely anxious group: exceeded all other treatments tried
48 hrs
Duration of measured anxiety relief (Garland 2023)

Panic Disorder — training the body out of false-alarm mode.

Panic disorder is driven by catastrophic misinterpretation of normal body sensations — a racing heart becomes a heart attack, shortness of breath becomes suffocation. The float pod is a controlled interoceptive environment where you can experience physical relaxation in a completely safe context.

Feinstein's research on interoception shows the float environment weakens the learned bond between cardiorespiratory sensations and anxiety — a direct intervention on the mechanism of panic.

Feinstein et al. (2018) enrolled n=12 Panic Disorder participants. Zero serious adverse events reported. PLOS ONE — doi:10.1371/journal.pone.0190292
Zero
Serious adverse events across 50 anxious/depressed participants
96%
Completed the full 60-minute session
d = 2.39
Effect size for "feeling refreshed" — largest measured outcome

The Science of Feeling Calm

Anxiety is a nervous system state.
The pod changes the state.

Float therapy doesn't teach you to cope with anxiety. It triggers a measurable physiological shift — cortisol suppression, sympathetic shutdown, interoceptive reset — built into 60 minutes of complete stillness.

01 · HPA Axis

The stress hormone that fuels your anxiety gets cut off at the source.

The hypothalamic-pituitary-adrenal axis is the chemical engine of anxiety — it keeps cortisol elevated and the nervous system in threat-detection mode. With zero sensory input, the HPA axis has no signal to respond to. Cortisol drops measurably within the first 20 minutes of a float and stays suppressed for hours afterward.

−31%cortisol post-session, on average
02 · Interoception

The body-to-brain feedback loop that sustains anxiety gets interrupted.

Anxiety isn't just in the mind — it lives in the feedback between body sensations (racing heart, shallow breath, muscle tension) and the brain's threat response. Feinstein's research shows the float environment weakens this bond by pairing cardiorespiratory sensations with deep physiological calm, effectively retraining the body's alarm signal.

d = 2.11effect size for serenity, single session
03 · Theta State

Your brain shifts out of hypervigilance and into its natural resting frequency.

The anxious brain is locked in high-frequency beta-wave activity — the brainwave of alertness, rumination, and threat-scanning. In the pod, the brain transitions into theta (4–7 Hz): the frequency of deep meditation, creative flow, and the hypnagogic state just before sleep. Hypervigilance cannot exist in theta state.

4–7 Hztheta range, sustained throughout the session

What Changes

Anxiety shifts on three timelines. The first starts within the hour.

01 This Hour

The anxiety spiral stops mid-cycle.

Within the first 20 minutes of a float, cortisol begins dropping and the sympathetic nervous system starts standing down. There is no phone to check, no thought left unfinished, no social cue to read. The machinery of anxiety runs on triggers — the pod removes all of them at once. Most floaters describe a point, usually around minute 30, where something they've been carrying for months quietly lets go.

d = 2.15
anxiety reduction, single session
02 Next 48 Hours

The relief lasts two days. Not two hours.

Feinstein's follow-up research, published in the Journal of Mood and Anxiety Disorders, tracked floaters for 48 hours after each session using real-time experience sampling. Anxiety, depression, and tension remained significantly lower for the full two-day window. The effect isn't just the float — it's a genuine reset that persists into the week.

48 hrs
measured relief duration post-float
03 This Month

Your baseline anxiety drops.

The cumulative effect is where long-term change lives. Garland et al. (2023) found that floaters arrived at sessions 5 and 6 with measurably lower pre-session anxiety than they had at session 1 — the body was learning a new default. Regular floaters report that situations that used to spike their anxiety start producing smaller and smaller responses. It isn't avoidance. The threshold genuinely shifts.

Sessions 5–6
baseline anxiety lower than session 1 — cumulative effect

What is Float Therapy?

A private pod. Complete quiet. Your nervous system does the rest.

Floating is effortless. You don't need experience, a meditation practice, or any special skill. Over 1,000 pounds of Epsom salt creates a perfectly buoyant environment — your body floats automatically, every muscle releasing without effort.

No light. No sound. No gravity. No social pressure. For 60 minutes, every external demand on your nervous system disappears. What's left is the baseline state your body was designed for — and hasn't visited in a long time.

  • Skin-temperature water — no sensation of where you end and the water begins
  • Lights and sound entirely on your terms — full blackout, or soft audio
  • Private pod, private suite — never shared, never timed against another guest
  • Triple-filtered between every session — hospital-grade water standards

The Research

One 60-minute float session produced an effect on anxiety larger than any single-session intervention ever measured in the clinical literature.

Dr. Justin Feinstein — Clinical Neuropsychologist, Director of the Float Research Collective, and holder of the first NIH grant ever awarded to study Floatation-REST — enrolled 50 adults with clinically diagnosed anxiety disorders across four diagnoses: generalized anxiety, social anxiety, PTSD, and panic disorder.

After a single 60-minute float, state anxiety dropped with a Cohen's d of 2.15 — approximately four times the effect size of SSRI antidepressants in equivalent study designs. Post-float anxiety levels in the clinical sample approached the levels observed in healthy, non-anxious controls.

96% completed the full session. 100% wanted to float again. 74% said it was the most relaxing thing they had ever experienced — more than any medication, therapy, or relaxation technique they had previously tried.

Frequently Asked

Common questions, answered.

Click any question to expand. Your studio team will walk you through everything else when you arrive.

The clinical evidence is strong. Feinstein's 2018 study showed a Cohen's d of 2.15 — roughly four times the effect size of SSRIs — from a single 60-minute session in adults with diagnosed anxiety disorders. Most floaters notice a shift during their first session. Regular floaters (twice a month or more) report durable reduction in baseline anxiety over time.
Feinstein's study enrolled 12 participants with Panic Disorder specifically, and zero serious adverse events occurred. The pod door never locks — you can open it and step out at any time. You also control the lights and audio throughout your session. Many people with panic disorder find the pod is one of the few places where their body stops sending false alarms.
The pod interior is significantly larger than a queen bed, and the lid opens from the inside at any time. Many guests who describe themselves as claustrophobic find the space feels expansive once they're floating — with no walls to see and no gravity pulling you toward them, the perceived space changes. You can also float with the lid open entirely.
Yes. Feinstein's 2018 study specifically noted that 40% of participants were on SSRIs or SNRIs at the time of floating — and all experienced significant anxiety reduction. Float therapy does not interact with psychiatric medications. Always continue any prescribed treatment; discuss any changes with your prescriber.
Meditation requires active effort to quiet the mind — a skill that takes years and fails when anxiety is severe. Floating removes the triggers that meditation asks you to resist. The pod does the work: no input means no anxiety response, regardless of how practiced you are. Feinstein's data showed floating produced an effect size (d=2.15) approximately four times larger than meditation (d~0.5) in equivalent anxiety measures.
One float helps most people that same day. Two floats a month is the threshold where members report durable change in their anxiety baseline. The Garland 2023 experience sampling study found the effects lasted 48 hours per session and accumulated across sessions — by sessions 5 and 6, pre-float anxiety was measurably lower than at session 1.
Feinstein's research is particularly focused on PTSD and interoception — how the body's sensations amplify trauma symptoms. His 2018 study enrolled 17 PTSD participants. The most severely affected group showed the largest benefits. The float environment is one of the only contexts where physiological safety is guaranteed at the brainstem level, not just conceptually.

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Peer-Reviewed Research

The clinical evidence behind Float for Anxiety.

PLOS ONE
Feinstein et al. · 2018

Examining the short-term anxiolytic and antidepressant effect of Floatation-REST

Justin Feinstein · Sahib Khalsa · Hung-wen Yeh · et al.
Key finding: A single 60-minute float session reduced state anxiety with Cohen's d = 2.15 in 50 clinically anxious adults across GAD, Social Anxiety, PTSD, and Panic Disorder. Post-float anxiety levels approached the non-anxious reference group. 100% of participants wanted to float again.
Read full paper →
Journal of Mood and Anxiety Disorders
Garland et al. · 2023

Reduced Environmental Stimulation Therapy (REST) in anxiety and depression: An experience sampling study

Sheila Garland · Maia Kredentser · Kirby Bibi · et al.
Key finding: Anxiety and depression relief persisted for a measured 48 hours after each float session. Repeated sessions produced additive effects — pre-session anxiety at sessions 5–6 was significantly lower than at session 1, indicating cumulative benefit.
Read full paper →
PLOS ONE · RCT
Garland et al. · 2024

A randomized controlled safety and feasibility trial of floatation-REST in anxious and depressed individuals

Sheila Garland · Maia Kredentser · Kirby Bibi · et al.
Key finding: Across 75 randomized participants and 6 sessions each, zero serious adverse events were recorded. Float-REST adherence (89%) significantly outperformed antidepressant medication adherence (37–49%) — and all participants reported positively-valenced float experiences.
Read full paper →
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