Peloids and Mud Therapy: What the Sources Say and Safety
Peloids are therapeutic muds used as warm packs and baths in spas. See what trials show for knee osteoarthritis, what is unproven for skin and detox, and the safety points.
Content last updated . This page has not been medically reviewed.
What is Peloids and Mud Therapy good for?
What the body uses it for, and how strong the evidence is. A normal job in the body is not proof that extra supplements add benefit; each card says which.
Mud packs and baths for knee osteoarthritis (warm mud, spa or clinic)
Preliminary or mixedA 2026 meta-analysis of 28 trials found less pain and better function with mud therapy, strongest in knee osteoarthritis; a 2020 analysis of 11 trials agreed for the short term; a 2016 analysis found no significant difference at the earlier follow-up.
Supplements: Promising but limited; see it as an add-on to usual care.
Spa therapy that includes mud, for knee osteoarthritis
Preliminary or mixedA 2018 review of 12 comparative trials found less pain, less painkiller use and better function, but methods differed, no meta-analysis was done and publication bias is possible.
Supplements: Applies to whole programs.
Heat delivery: why peloids are used warm
Lab or animal research onlyIn a lab study, spa peloids released heat up to four times more slowly than the same amount of water, which helps explain their use as warm packs.
Supplements: Does not show mud works better than any warm pack.
Marine and Dead Sea climate programs
Preliminary or mixedA 2026 review of nine studies (465 people) found short-term improvements in pain and function, but the pooled pain result was inconclusive and the authors say limits prevent firm conclusions.
Supplements: Mixed.
Face and body masks for acne, eczema or 'glow'
Not enough evidenceProper evidence not found in the sources we read. A 2025 review of mud for skin treatment discusses ideas and future research.
Supplements: Insufficient evidence.
Detox and mineral-absorption claims: claim check
Not enough evidenceNCCIH reports a 2015 review that found no compelling research that detox programs remove toxins. We found no study showing mud removes toxins or delivers minerals to the body.
Supplements: No good evidence of benefit.
Pregnancy, babies, heart or blood pressure problems, medicines
Not enough evidenceThe sources we read give no separate information for these groups, and the NHS list of osteoarthritis treatments does not mention mud or spa treatment.
Supplements: Ask a clinician first.
Connected topics
Open a group to see how each topic connects and how strong the evidence is.
Health goals (2)
- Joint SupportPreliminary or mixed
Warm mud packs and baths have reduced knee osteoarthritis pain in several analyses; quality varies.
- Mobility SupportPreliminary or mixed
Meta-analyses report better physical function in knee osteoarthritis; add-on only.
Body systems (3)
- Bones, Joints & MusclesPreliminary or mixed
Used mainly for joint and muscle problems; trial support strongest for knee osteoarthritis.
- Integumentary SystemDocumented risk
Skin redness is a documented effect.
- Pain & InflammationPreliminary or mixed
Pain scores fell in several analyses; mixed quality.
Body parts (2)
Functional actions (2)
- Joint SupportPreliminary or mixed
Better joint function in knee osteoarthritis analyses.
- Pain ReliefPreliminary or mixed
Less pain in several analyses; add-on to usual care.
Conditions & symptoms (1)
- Osteoarthritis, KneePreliminary or mixed
Most studied use; 2026 and 2020 analyses found less pain, a 2016 analysis was not significant early on.
Documented risks and interactions (3)
- Side effects: skin redness and tiredness. In the 2026 meta-analysis the most common events were skin redness (6.5%) and brief tiredness (4.8%); serious events were not more common than in comparison groups. Safety reporting across trials is inconsistent.
- Contamination and site-to-site variation. A study of peloids from 13 Serbian spas found pH, salt and elements varied widely; radioactivity was within ranges commonly reported and a skin-exposure screening found no significant non-cancer risk, but the authors stress testing each source.
- Swallowing mud. The sources we read do not describe swallowing therapeutic mud. If someone swallowed a mud product and is unwell, call Poison Help (US 1-800-222-1222) or your local emergency number.
The short answer: mud packs and mud baths have the best support for knee osteoarthritis pain, but the research is mixed in quality, and there is no good evidence for "detox". A 2026 review of 28 randomized trials found less pain and better function with mud therapy, with serious side effects not more common. [3] Earlier pooled analyses disagree in places, and reviewers keep asking for better trials. [4][6][8] Mud therapy is for the outside of the body. We found nothing supporting swallowing it.
A peloid is a mud used for treatment or beauty, mostly in spas and clinics. This page separates spa and trial findings from seller claims, and it keeps packs on a joint apart from face masks and from swallowing.
What peloids are
A peloid is a mud-based preparation made of a liquid part (often mineral or sea water) and a solid part (clay or other fine material, sometimes with organic matter). The solid part helps the mixture stay stable and easy to handle. [1] Peloids are used warm: spa peloids released heat up to four times more slowly than the same amount of water in one lab study. [1] That is one reason they are used as hot packs. Spa centers use peloids mainly for muscle and joint problems, above all knee osteoarthritis, and less for back pain and psoriatic arthritis. [1] They are also used in skin care. [10]Peloids differ by place, mix and processing. A study of peloids from 13 spas in Serbia found acidity (pH 6.59 to 9.52), salt content and elements varied widely from site to site. [2] A trial result for one spa mud is therefore not a promise for another mud or a cosmetic product. Examples: Dead Sea mud, and clay types in Clay types at a glance.
Claims and what the sources found
| Claim or use | What the best source found | Evidence label | Route, product and who was studied |
|---|---|---|---|
| Mud packs or baths for knee osteoarthritis | 2026 meta-analysis of 28 randomized trials (musculoskeletal disorders): pain lower right after treatment and still lower at 3 and 6 months; largest effect in knee osteoarthritis. [3] A 2020 analysis of 11 trials (1,106 people) found less pain and better function in the short term. [7] A 2016 analysis of 10 trials (1,010 people) found no significant difference at the end of follow-up under 4 months, with very mixed results. [6] | Promising but limited | Warm mud packs or baths in spa or clinic settings; adults with knee osteoarthritis |
| Mud as one part of a plan for osteoarthritis | A 2024 review of 19 studies concluded mud therapy is a promising part of an integrated plan alongside drugs or physiotherapy. [8] A 2013 review of 20 studies rated risk of bias as moderate and asked for stronger methods. [4] | Promising but limited | Mostly mud baths and packs for the knee, one hand study |
| Spa therapy (mud plus bathing) for knee osteoarthritis | 2018 review of 12 comparative trials: lower pain, less painkiller use and better function, but widely different methods, no meta-analysis, possible publication bias. [5] | Promising but limited | Whole spa programs; effect of the mud alone is not separated |
| Marine or Dead Sea climate programs for muscle and joint disorders | 2026 review of nine studies (465 people): short-term improvement, but only two studies could be pooled for pain, the result was inconclusive, and the authors say limits prevent firm conclusions. [9] | Mixed | Climate and seawater programs, mud is one element |
| Face or body masks for acne, eczema or "glow" | Proper evidence not found. A 2025 review of mud for skin treatment mostly discusses ideas and future research. [10] | Insufficient evidence | Cosmetic mud on skin |
| "Detox", "pulls toxins out through the skin", "mineral absorption" | NCCIH reports a 2015 review that found no compelling research that detox programs remove toxins. [13] We found no study that shows mud removes toxins or delivers minerals to the body. | No good evidence of benefit | Seller claim |
| Swallowing mud or "peloid" supplements | Proper evidence not found in the sources we read. | Insufficient evidence | Not advised |
Limits: you can feel and see a warm mud pack, so people know which treatment they got, and pain is self-reported. Heat itself may explain part of the effect, because the studies compare mud with no treatment or usual care more often than with warm, plain packs. We did not find a source that separates these. Spa stays also bring rest, exercise and a change of place. Several reviews say trial quality varies. [4][5][6]
Safety by group
- Swallowing and poisoning. The sources we read do not describe swallowing therapeutic mud. If someone swallowed a mud product and is unwell, call Poison Help (US 1-800-222-1222) or your local emergency number; call 911 for collapse, seizure or trouble breathing. [12] See Poisoning: urgent help.
- Side effects in trials. In the 2026 meta-analysis, the most common side effects were skin redness (6.5%) and passing tiredness (4.8%); serious side effects were not more common than in comparison groups. [3] Safety reporting varies between trials. [9]
- Contamination. The Serbian study found radioactivity within ranges commonly reported for therapeutic muds, and a screening for skin exposure to potentially toxic elements found no significant non-cancer risk, yet it stresses testing each source. [2] That study is about 13 sites, not every product. See Heavy metals in natural ingredients.
- Skin. Redness is documented. [3] Burns from packs that are too hot, and allergy to a particular mud: the sources we read do not describe them in detail. See Clay face masks: safety and patch testing.
- Heart, blood pressure, fainting. The mud trials we read give no separate figures for heart or blood pressure problems. For hot water in general see fainting after hot water and balneotherapy.
- Pregnancy, babies and children. The sources we read do not describe mud therapy in pregnancy or for babies. Ask a clinician; see Pregnancy and breastfeeding.
- Medicines. Not described for skin use in the sources we read; see medication interactions.
- Standard care. The NHS lists exercise, weight loss, pain medicines and hot or cold packs for osteoarthritis and does not mention mud or spa treatment. [11]
How it is used and what to look for on a label
- In spas: a warm pack or bath of mud, usually for the knee or back, sometimes as a course of visits. A clinic should explain temperature, time and who should not use it.
- At home: "peloid" or mud masks and wraps. These are cosmetic products; the trial results above are for spa-grade programs and do not carry over to them.
- Look for the mud's source and whether metals are tested; a label cannot tell you what is in the jar. See product quality and contamination.
- Red flags: "detoxifies", "removes heavy metals", "safe to eat".
Related pages
Frequently asked questions
Does mud therapy work for osteoarthritis?
It may help knee pain and function for a while. A 2026 meta-analysis of 28 trials and a 2020 analysis of 11 trials found benefit, while a 2016 analysis did not at the earlier follow-up, and reviewers ask for better trials. [3][7][6]
Does mud detox the body?
We found no evidence it does. NCCIH reports a 2015 review that found no compelling research that detox programs remove toxins. [13]
Is it safe to swallow mud or clay from a spa?
We found nothing showing it is safe. If someone swallowed it and is unwell, call Poison Help at 1-800-222-1222 or your local emergency number. [12]
What side effects were reported?
Skin redness and brief tiredness were the most common in a 2026 meta-analysis, and serious side effects were not more common than in comparison groups. [3]
Is it safe in pregnancy or for children?
The sources we read do not say. Ask a clinician before using a warm mud pack, especially if you are pregnant, have heart or blood pressure problems, or are treating a child.
References
- Maraver F, et al. Peloids as thermotherapeutic agents. Int J Environ Res Public Health. 2021;18(4):1965. PubMed 33670514 (abstract read via Europe PMC). Laboratory study with clinical background. Read 2026-10-24.
- Mutić T, et al. Chemical and radiological characterization of Serbian peloids: implications for therapeutic safety. Toxics. 2026;14(5):355. PubMed 42198481 (abstract read). Laboratory study. Read 2026-10-24.
- Balakrishna S, et al. Effectiveness and safety of mud therapy (pelotherapy) for musculoskeletal disorders: a systematic review and meta-analysis. J Lifestyle Med. 2026;16(2):39-48. PubMed 42719543 (abstract read). Read 2026-10-24.
- Espejo-Antúnez L, et al. Clinical effectiveness of mud pack therapy in knee osteoarthritis. Rheumatology (Oxford). 2013;52(4):659-668. PubMed 23236190 (abstract read via Europe PMC). Read 2026-10-24.
- Fraioli A, et al. Efficacy of spa therapy, mud-pack therapy, balneotherapy, and mud-bath therapy in the management of knee osteoarthritis: a systematic review. Biomed Res Int. 2018;2018:1042576. PMC6036842. Read 2026-10-24.
- Xiang J, Wu D, Li J. Clinical efficacy of mudpack therapy in treating knee osteoarthritis: a meta-analysis of randomized controlled studies. Am J Phys Med Rehabil. 2016;95(2):121-131. PubMed 26203645 (abstract read). Read 2026-10-24.
- Hou C, et al. The short-term efficacy of mud therapy for knee osteoarthritis: a meta-analysis. Medicine (Baltimore). 2020;99(17):e19761. PubMed 32332614 (abstract read). Read 2026-10-24.
- Maier GS, et al. Effectiveness of mud-pack therapy and mud-bath therapy in osteoarthritis: a systematic review. Complement Med Res. 2024;31(1):30-39. PubMed 38008065 (abstract read). Read 2026-10-24.
- Müller TL, et al. Climatotherapy in marine and Dead Sea environments for musculoskeletal and rheumatologic conditions: a systematic review of effectiveness and safety. Int J Biometeorol. 2026;70(8). PubMed 42489765 (abstract read). Read 2026-10-24.
- Almeida L, Rocha F, Candeias C. Pelotherapy, thalassotherapy, and electrotherapy for skin treatment: current insights and future perspectives on electropelotherapy. Int J Biometeorol. 2025;69(9):2157-2169. PubMed 40531339 (abstract read). Review. Read 2026-10-24.
- NHS. Osteoarthritis: treatment. Read 2026-10-24.
- Poison Control (America's Poison Centers / National Capital Poison Center). Poison Control home page. Read 2026-10-24.
- National Center for Complementary and Integrative Health (NIH). “Detoxes” and “Cleanses”: What You Need To Know. Last updated March 2025. Read 2026-10-24.