Flotation Tanks and Restricted Environmental Stimulation (Float Therapy): What Studies Show and Cautions
What float tanks (flotation-REST) are, what small studies found for stress, anxiety and pain, the limits of that evidence, and the hygiene, mental-health and medical cautions to know first.
Content last updated . This page has not been medically reviewed.
Check Before You Float
Float therapy is a relaxation practice, not a proven treatment for any condition. Government of Western Australia health advice says floatation is not recommended if you have claustrophobia, epilepsy, kidney disease, low blood pressure, any contagious disease (including diarrhoea or gastroenteritis, and for 14 days after), open wounds or skin ulcers. [1] It advises checking with a health practitioner first if you are pregnant or concerned about heart conditions, asthma, sensitivity to chlorine, bromine, sulfate or magnesium, severe skin conditions such as psoriasis and eczema, or psychosis. [1] The same page says not to use a tank under the influence of drugs or alcohol. [1] See alcohol, drugs and hydrotherapy. In the US, call 911 in an emergency. If you are in a mental health crisis, call or text 988.What a Float Tank Is
The Western Australian Department of Health describes a float tank as a lightless, soundproof tank partially filled with salty water. [1] The water is a solution of water and Epsom salts, extremely buoyant, usually around 300 millimetres deep, and heated to about outer skin temperature, approximately 35°C. [1] That is a description of how tanks are run, not advice for any person. You float on your back. [1] Names include float tank, isolation tank, sensory deprivation tank and Restricted Environmental Stimulation Therapy (REST) tank. [1] For the ingredient itself, see Epsom salt. In the research literature the tank method is called flotation-REST, meaning an enclosed tank of buoyant saltwater used to promote relaxation. [2]Why People Say It Works (Proposed, Not Established)
The explanation is that cutting sound, light, touch and gravity cues creates relaxation. The health department states that it is believed floating without external stimulation can create a feeling of relaxation. [1] A 2026 scoping review states that physiological and biomarker effects remain unclear. [3] Treat mechanisms as ideas, not findings.What Studies Show
Float research is small.| Question | What the source found | Label |
|---|---|---|
| Overall literature | A 2025 review found 63 studies (1,838 participants); positive effects on pain, stress, mental well-being and clinical anxiety; limited to no effect on sleep disorders and smoking cessation. The authors say the small number of studies limits generalizing. [2] | Promising but limited |
| Chronic pain | A 2026 scoping review found eight studies (six randomized, 401 participants) and called flotation-REST promising for pain and well-being; designs were too varied to pool. [3] | Promising but limited |
| Anxiety and depression, single session | A 2018 open-label study of 50 people with anxiety-related disorders reported lower state anxiety after a 1-hour float; the authors said it needs replication in larger controlled trials. [4] | Insufficient evidence (no control group) |
| Repeated sessions | A 2024 single-blind trial randomized 75 people (from 1,715 screened) to six sessions in different formats and reported no serious adverse events. The trial was about feasibility and safety, and larger trials of clinical efficacy are warranted. [5] | Feasibility only |
| Sleep | Mixed: limited to no effect on sleep disorders in the 2025 review. [2] | Mixed |
One author of the 2024 trial lists a Float Research Collective affiliation. [5] Float trials also cannot be fully blinded, since people know when they are in a tank, so expectation can shape self-reported relaxation. A 2026 survey of 61 users found users more often reported depression, daily anxiety and sleep disturbance than a national benchmark, but the authors say this reflects current status rather than changes due to flotation. [6] It tells us who uses floats, not whether floats help.
Claims we did not find supported in the sources we read: that floating treats PTSD, detoxifies the body, or cures addiction. Proper evidence not found (searched: PubMed for flotation-REST reviews and trials, 2026-10-22).
Hygiene and Infection
The ME Association says concerns have been raised about waterborne infection spread if the water is not changed as regularly as it should be. [8] In Western Australia, commercial float centres must follow a code of practice. The health department says users should shower first, the whole solution must be filtered three times between sessions, and tanks are disinfected with ultraviolet light plus bromine or chlorine depending on design. [1] It also says households with private tanks are not subject to the same conditions as commercial facilities. [1] Rules in other states and countries are not described in the sources we read, so ask a facility how it cleans and when it last checked its water. See how to check a pool, spa or clinic.Drowning, Claustrophobia and Getting Out
The same health page says drowning is possible but extremely unlikely, that you stay afloat if you fall asleep, that tanks have an internal call alarm and light, and that you can get out at any time. [1] It adds that salt water in the eyes can cause discomfort and that senses may feel heightened after a session. [1] If you have epilepsy, see epilepsy, seizures and water safety. Do not practise breath-holding or over-breathing in a tank or any water; see breath-holding risks.Frequently asked questions
Is float therapy proven to treat anxiety?
No. Small studies, including one without a control group, reported less anxiety after floating, and reviewers call for larger controlled trials. [4][5]
Who should not use a float tank?
Western Australian health advice lists claustrophobia, epilepsy, kidney disease, low blood pressure, contagious illness and open wounds, and says to check first with pregnancy, heart conditions or psychosis. [1]
Can floating cause hallucinations?
Occasional reports of psychotic-like hallucinations exist, and sensory deprivation in general is linked to hallucinations in some settings. [8][7]
Can you drown in a float tank?
The health department says it is possible but extremely unlikely, and that you stay afloat if you fall asleep. [1]
Are float tanks clean?
It depends on the operator. The ME Association raises infection concerns where water is not changed often enough, and Western Australia requires filtration and disinfection in commercial centres. [8][1]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Mental Health Cautions
Cost, Access and Regulation
References
- Government of Western Australia, Department of Health. Floatation tanks (Healthy WA). Read 2026-10-22.
- Lashgari E, et al. A systematic review of flotation-restricted environmental stimulation therapy (REST). BMC Complement Med Ther 2025. Read 2026-10-22.
- Stuart SJ, et al. A scoping review of flotation-REST for chronic pain and associated comorbidities. J Pain Res 2026. Read 2026-10-22.
- Feinstein JS, et al. Examining the short-term anxiolytic and antidepressant effect of Floatation-REST. PLoS One 2018. Read 2026-10-22.
- Garland MM, et al. A randomized controlled safety and feasibility trial of floatation-REST in anxious and depressed individuals. PLoS One 2024. Read 2026-10-22.
- Adamji T, et al. Characterizing the profile of individuals who undergo flotation-REST: a cross-sectional survey. Am J Lifestyle Med 2026. Read 2026-10-22.
- Marazziti D, et al. Sensory deprivation and the brain: neurobiological mechanisms, psychological effects, and clinical implications. Brain Sci 2026. Read 2026-10-22.
- The ME Association (UK). Alternative treatments: Flotation tank. Read 2026-10-22.