Treatment & Procedure
Infrared-A (wIRA)
Equipment
Water-filtered infrared A is heat that goes deep into the tissue without burning the skin. Unlike many heat treatments, there are genuine randomized studies for it, mainly on wound healing. That does not apply to the promises from the wellness and biohacking world.
In short
Water-filtered infrared A, wIRA for short, is thermal radiation in which a water filter removes the components that mainly heat the skin surface. This lets more heat penetrate into deeper tissue. It is well supported that wIRA raises tissue temperature and tissue oxygen pressure and, in several randomized studies, speeds up wound healing and relieves wound pain. For chronic pain there are smaller positive studies; for recovery in healthy people or rejuvenation there are none. The catch: the studies come predominantly from one network of researchers, and in the largest study the main finding was not significant in the strictest analysis.
What wIRA is
Infrared radiation is divided into three ranges. Infrared A is the short-wave part; it penetrates the deepest. Ordinary heat lamps also emit a lot of infrared B and C, which is absorbed mainly in the uppermost layers of the skin and quickly burns there. With wIRA, the light passes through a water cuvette that largely filters out these components, similar to the way water vapor in the atmosphere filters sunlight.
The result is heat that feels pleasant and warms the tissue at a depth of a few centimeters. Measurements in studies show a temperature 2.7 degrees higher and an oxygen partial pressure 32 percent higher at a depth of 2 centimeters. wIRA is used locally on wounds or painful areas of the body and as a heat source for mild whole-body hyperthermia.
How to recognize a reputable offer
A good offer names a specific goal, such as a poorly healing wound or a painful region, instead of promising rejuvenation in general. It pays attention to distance, duration and how the skin feels, and protects the eyes. For wounds, wIRA is part of normal wound care, not a replacement for it. Be cautious with promises about mitochondria, detoxification or cellular rejuvenation; there are no studies for these.
What is well supported
For wounds, the data are unusually good for a physical procedure. A 2016 review found 7 prospective studies, 6 of them randomized, in which standard care plus wIRA was always compared with standard care alone. In children with severe burns, the wound area shrank by 89.2 versus 49.5 percent after 9 days, chronic venous leg ulcers closed after 14 instead of 42 days, and after abdominal surgery the wounds healed better and were less painful.
There are also signals for pain. In a sham-controlled study with 41 people with fibromyalgia, 6 sessions of mild whole-body hyperthermia with wIRA over 3 weeks reduced pain, and the effect was still measurable in week 30. In axial spondyloarthritis in a rheumatology clinic and in severe Raynaud’s syndrome, as a complement to standard therapy, smaller short-term improvements were seen.
What the studies show
Wound healing after abdominal surgery, 2006
Hartel and colleagues irradiated the surgical wound of 111 patients twice daily with wIRA plus visible light or with visible light only. Wound healing was rated at 88.6 versus 78.5 on a scale of up to 100, the oxygen pressure under the skin was 41.6 versus 30.2 mmHg, and pain fell by 13.4 points during irradiation, while it did not fall at all in the control group.
Wound infections after a single irradiation, 2013
Künzli and colleagues irradiated 400 patients once for 20 minutes with wIRA or a sham before abdominal surgery; patients and assessors did not know the allocation. In the analysis of patients with complete data, wound infections occurred in 5.1 versus 12.1 percent. In the stricter analysis of all randomized patients, the figures were 16 versus 20 percent, and this difference was not significant.
Fibromyalgia, sham-controlled, 2023
Langhorst and colleagues randomized 41 people with fibromyalgia to mild whole-body hyperthermia with wIRA or a sham treatment in which an insulating foil largely blocked the radiation. After 4 weeks, pain was significantly lower in the active group, and likewise after 30 weeks.
Where the data stop
The good wound data have two limitations. First, the studies come predominantly from one network of researchers. The first author of the large review works for a foundation that funds wIRA research, and the review argues that the studies, if anything, underestimate the benefit. Second, not every finding withstands the strictest test: in the largest study, with 400 patients, the difference in wound infections was not significant in the analysis of all randomized patients, and in a blinded study on leg ulcers the primary variable missed significance, even though other values were better.
Above all, however, these studies answer a different question from the one asked in biohacking. They show a benefit for wounds and for certain pain conditions. No studies were found on recovery in healthy people, mitochondrial function or rejuvenation. The pain studies are small and short, and only the fibromyalgia study had a sham treatment.
Status, approval and legal
wIRA is a physical procedure used in hospitals for wounds, in rheumatology and as a heat source for hyperthermia. In outpatient use outside these indications, it is usually a self-pay service. Unlike solariums, wIRA contains no UV radiation.
Safety
Hardly any adverse effects occurred in the studies; the Raynaud study reported none. Skin aging is debated: according to a 2008 review, more than 65 percent of infrared A radiation reaches the dermis and, as part of sunlight, contributes to skin aging. A cell culture study, by contrast, found that wIRA does not trigger the collagen breakdown marker typical of this, unlike UV-A. There are no long-term data in humans. Anyone with impaired heat perception, for example due to nerve damage, circulatory disorders or acute inflammation, should consult a physician beforehand; for whole-body hyperthermia this also applies to cardiovascular disease and pregnancy. The eyes should not be irradiated directly.
BK-Score Supported, with caveats
| Human evidence | 6 | |
|---|---|---|
| Mechanism | 7 | |
| Safety data | 7 | |
| Hype gap | 4 | |
| Track record of use | 6 |
For a clearly defined indication there are genuine controlled data. A 2016 review summarizes 7 prospective studies on wound healing, 6 of them randomized, each comparing standard care plus wIRA with standard care alone. Reported results include a reduction in wound area of 89.2 versus 49.5 percent in children with burns after 9 days and ulcer closure after 14 instead of 42 days. Measured in humans are higher tissue temperature and a higher oxygen partial pressure in the tissue (41.6 versus 30.2 mmHg after abdominal surgery). The limitations: the studies come predominantly from one network of researchers, the first author of the review works for a foundation that funds this research, and the review argues that the studies underestimate the benefit. In the largest study, with 400 patients, wound infections fell from 12.1 to 5.1 percent in the analysis of patients with complete data, but in the analysis of all randomized patients (16 versus 20 percent) the difference was not significant. For pain there is one small sham-controlled study in fibromyalgia with a positive result and smaller studies without sham control. Above all: these data concern wound healing and certain pain conditions. For the goals advertised in biohacking – recovery, mitochondria, rejuvenation – they are not evidence but a different question.
The score rates the state of knowledge, not the substance. “Safety data 9” means well studied – not harmless. “Track record of use 9” means used long and widely – that is not proof of efficacy.
Subjective assessment by Biohacking Kompakt based on published scoring rules – not a scientific rating and not a medical recommendation. Rules and all ratings (German)
Frequently asked questions about Infrared-A (wIRA)
What is water-filtered infrared A?
Thermal radiation in which a water filter removes the components that mainly heat the skin surface. As a result, the heat penetrates deeper into the tissue and is better tolerated. The principle resembles the filtering of sunlight by water vapor in the atmosphere.
What is wIRA supported for?
Best of all for wound healing, with several randomized studies in surgical wounds, burns and chronic leg ulcers. In fibromyalgia, mild whole-body hyperthermia with wIRA reduced pain in a sham-controlled study.
Does infrared A help with back pain?
There are few data on this. In axial spondyloarthritis, pain decreased in the short term as a complement to treatment in a rheumatology clinic; there was no sham treatment there. No dedicated studies were found for non-specific back pain.
Is wIRA the same as an infrared cabin?
Not necessarily. Depending on the emitter, infrared cabins work with different proportions of infrared A, B and C, with B and C mainly warming the skin. wIRA filters these components out and warms more deeply. The study results apply to wIRA, not automatically to every cabin.
Does infrared A age the skin?
This is debated. According to one review, infrared A from sunlight contributes to skin aging; a cell culture study, by contrast, found no typical collagen breakdown from wIRA. Long-term data in humans are lacking.
Does wIRA promote recovery and mitochondria?
There are no studies on this. What has been measured is higher tissue temperature and more oxygen in the tissue, and this is where the benefit for wounds comes from. Claims about recovery in healthy people or cellular rejuvenation have not been studied.
The podcast episode (in German)
Episode 73
Whole-body hyperthermia & infrared: heat therapy fact-checked
The podcast by Paul Höser (Episode 73) · with Paul & Paula. Sauna, infrared cabin and medical whole-body hyperthermia compared – and why water-filtered infrared A (wIRA) is today the method of choice when core temperature is to be raised in a controlled way. Information only, no usage recommendation.
Related
- Same categoryIHHT – hypoxia training
- Same categoryVNS analysis (HRV)
- Same categoryBioadaptive impulse treatment
- Related topicWhole-body hyperthermia
- Related topicRed light / photobiomodulation (PBM)
- Related topicCryotherapy (whole-body cold chamber)
- Related topicSpinal regeneration
- Related topiceSpineBot
- Related topicFloating (isolation tank)
Sources
- Hoffmann G, Hartel M, Mercer JB, Ger Med Sci 2016 — wIRA for wound healing, review
- Hartel M et al., Br J Surg 2006 — wIRA after abdominal surgery, RCT
- Künzli BM et al., Ann Surg 2013 — preoperative wIRA irradiation and wound infections, RCT
- Schumann H et al., Br J Dermatol 2011 — wIRA in chronic venous leg ulcers, RCT
- Langhorst J et al., J Clin Med 2023 — mild wIRA whole-body hyperthermia in fibromyalgia, sham-controlled RCT
- Klemm P, Aykara I, Lange U, 2022 — wIRA in axial spondyloarthritis
- Schulz N et al., Int J Hyperthermia 2026 — wIRA in systemic sclerosis and Raynaud’s syndrome, RCT
- Schroeder P, Haendeler J, Krutmann J, Exp Gerontol 2008 — infrared A and skin aging
- Gebbers N et al., Ger Med Sci 2007 — wIRA and MMP-1 in skin fibroblasts
Open in the database – with search, filters and comparison (German app)
Information only, not medical advice and not a usage or dosage recommendation. Prescription-only and unapproved substances belong in the hands of a physician. Last updated: 2026-09-30.