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Some physicians and scientists suggest that administering chemotherapy, immunotherapy, or radiotherapy at a specific time of day can improve response to treatment. 

How can hyperbaric oxygen therapy help you? What the research says

We summarize the clinical evidence for each medical benefit here. We begin with our assessment of the strength of evidence within each category, followed by a brief summary of individual studies or reviews of several studies. In assessing the strength of evidence, we consider the study design, number of participants, and the size of the treatment effect (how much outcomes changed with treatment).

To see more details, click the plus sign to the right of any section.

Improving treatment outcomes

Is hyperbaric oxygen therapy linked to improved survival? Is it linked to less cancer growth or metastasis? Does it enhance the anticancer action of other treatments or therapies? We present the evidence.

Bladder cancer

No evidenceoverall, one or more studies did not demonstrate that a treatment or intervention led to an expected outcome; this does not always mean that there is no effect in clinical practice, but that the studies may have been underpowered (too few participants) or poorly designed. Larger, well-designed studies provide more confidence in making assessments.: People with bladder cancer receiving HBOT during radiation showed no evidence of an effect on metastasis or survival, but did show an increased risk of radiation injury.
Breast cancer

No evidence: People receiving HBOT during chemotherapy showed no evidence of an effect on progression or survival in one study.
Gynecologic cancer

No evidence: People with cervical cancer receiving HBOT during radiation showed no evidence of an effect on metastasis or survival, but did show an increased risk of radiation injury.
Head and neck cancer

Good evidencesignificant effects in one large or several mid-sized and well-designed clinical studies (randomized controlled trials (RCTs) with an appropriate placebo or other strong comparison control or observational studies that control for confounds) (this is the CancerChoices definition; other researchers and studies may define this differently): People with head and neck cancer who received HBOT during radiation showed better response to treatment and better survival across several studies. People with laryngeal cancer who received HBOT during radiation had a higher rate of survival without laryngectomy (surgery to remove the voicebox) in one study
(preliminary evidencesignificant effects in small or poorly designed clinical studies OR conflicting results in adequate studies but a preponderance of evidence of an effect (this is the CancerChoices definition; other researchers and studies may define this differently)). However, there is also evidence of radiation injury and neurological damage among people receiving HBOT during radiation.
Liver cancer

Weak evidenceone or more case studies, supported by animal evidence OR small treatment effects of limited clinical significance OR studies with no controls OR weak trends of effects (this is the CancerChoices definition; other researchers and studies may define this differently): People who received HBOT at the end of surgery to remove liver cancer showed weak evidence of longer survival and less hyperbilirubinemia (jaundice) in one small study, and markers suggesting less liver injury in another small study.
Pancreatic cancer

Preliminary evidencesignificant effects in small or poorly designed clinical studies OR conflicting results in adequate studies but a preponderance of evidence of an effect (this is the CancerChoices definition; other researchers and studies may define this differently): People with pancreatic cancer who received HBOT before a pancreatoduodenectomy (Whipple procedure) had fewer lung-related complications from surgery in one small study.

Managing side effects and promoting wellness

Is hyperbaric oxygen therapy linked to fewer or less severe side effects or symptoms? Is it linked to less toxicity from cancer treatment? Does it support your quality of life or promote general well-being? We present the evidence.

Cognitive difficulties

Modest evidencesignificant effects in at least three small but well-designed randomized controlled trials (RCTs), or one or more well-designed, mid-sized clinical studies of reasonably good quality (RCTs or observational studies), or several small studies aggregated into a meta-analysis (this is the CancerChoices definition; other researchers and studies may define this differently): People with cerebral edema (fluid in the brain) after surgery to remove a meningioma who were treated with HBOT showed less edema and better overall function in one mid-sized study, though another, smaller study did not find a statistically significant effect on cognitive impairment.
Gastrointestinal side effects

Insufficient (mixed) evidencepreclinical evidence only OR clinical studies with such poor or unclear methodology that no conclusion can be drawn OR conflicting findings across clinical studies with no preponderance of evidence in one direction; conflicting evidence occurs when studies find conflicting effects (positive effect vs no effect or negative effect) with the same treatment and the same general study population (same cancer type, for example) (this is the CancerChoices definition; other researchers and studies may define this differently): People with proctitis (inflammation of the rectal lining) after pelvic radiation who received HBOT showed a higher cure rate in one combined analysis of studies, but insufficient evidence in another.
Lymphedema

No evidenceoverall, one or more studies did not demonstrate that a treatment or intervention led to an expected outcome; this does not always mean that there is no effect in clinical practice, but that the studies may have been underpowered (too few participants) or poorly designed. Larger, well-designed studies provide more confidence in making assessments.: People with lymphedema following breast cancer treatment who received HBOT showed improved quality of life in one study. However, another study did not show any difference in quality of life.
Neuropathy and other neurological symptoms

Radiation optic neuropathy

Good evidencesignificant effects in one large or several mid-sized and well-designed clinical studies (randomized controlled trials (RCTs) with an appropriate placebo or other strong comparison control or observational studies that control for confounds) (this is the CancerChoices definition; other researchers and studies may define this differently): People who had received radiation to the visual axis, which can cause radiation optic neuropathy (vision loss), and who received HBOT were more likely to have improved or stable vision in a combined analysis of 14 studies.

Brachial plexopathy

Weak evidenceone or more case studies, supported by animal evidence OR small treatment effects of limited clinical significance OR studies with no controls OR weak trends of effects (this is the CancerChoices definition; other researchers and studies may define this differently): People with brachial plexopathy after radiation treatment who received HBOT showed a weak trend toward better temperature sensation but no evidence of an effect on pain or paralysis.
Oral symptoms

Osteoradionecrosis and dental implant failure

Insufficient (conflicting) evidence: While some studies have found that people who received radiation to the head or neck and had to have tooth extractions were less likely to develop osteoradionecrosis (death of bone, in this case in the jaw) with HBOT, the majority of HBOT studies do not find this effect. A recent combined analysis found that while people who received HBOT did have a slightly lower risk of osteoradionecrosis after radiation and tooth extraction, the effect was smaller than that of conventional treatments, such as antibiotics.

Other oral symptoms

Preliminary evidencesignificant effects in small or poorly designed clinical studies OR conflicting results in adequate studies but a preponderance of evidence of an effect (this is the CancerChoices definition; other researchers and studies may define this differently): People who had had head and neck radiation while receiving HBOT showed less dry mouth across two studies (though not as much of an improvement as with other treatments) and a trend toward less pain in one.
Skin and tissue side effects

No evidence: People with radiation-induced dermatitis (skin inflammation) who received HBOT showed no evidence of an effect on the severity of the dermatitis in a small, low-quality study.
Urinary symptoms

Insufficient (mixed) evidence: People with cystitis (bladder inflammation) caused by pelvic radiation who received HBOT showed improved urinary symptoms in one small study but no evidence of an effect in another small study.
Side effects not specific to cancer

Oral symptoms

Preliminary evidence: People with jaw cysts receiving HBOT showed better surgical outcomes in one study, and people with osteonecrosis of the jaw from bisphosphonates who received HBOT showed faster healing in another study.
Hyperbaric oxygen combined with other therapies

HBOT combined with massage: People who received HBOT and massage after pharyngeal an or laryngeal surgery showed faster wound healing in one study.

Keep reading about timing of therapies

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See all our reviews of complementary therapies

Author

Sophie Kakarala

Research Assistant
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Sophie received her Bachelor of Arts from the University of Cambridge, where she studied Middle Eastern languages and the philosophy of science. She then completed a premedical post-baccalaureate at the City University of New York. Before joining CancerChoices, she worked for several years at the Cornell Center for Research on End-of-Life Care, where she helped to conduct research on terminal illness and grief. Working in end-of-life research filled her with the conviction that all patients deserve free, accessible, and scientifically accurate information about the therapies available to them. While taking classes in anthropology, she also became curious about traditional medical knowledge and philosophies. These interests led her to CancerChoices. She is delighted to be part of CancerChoices’s work creating rigorous, evidence-based treatment guides for patients and physicians.

Sophie Kakarala Research Assistant

Nancy Hepp, MS

past Lead Researcher
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Ms. Hepp is a researcher and communicator who has been writing and editing educational content on varied health topics for more than 20 years. She serves as lead researcher and writer for CancerChoices and also served as the first program manager. Her graduate work in research and cognitive psychology, her master’s degree in instructional design, and her certificate in web design have all guided her in writing and presenting information for a wide variety of audiences and uses. Nancy’s service as faculty development coordinator in the Department of Family Medicine at Wright State University also provided experience in medical research, plus insights into medical education and medical care from the professional’s perspective.

Nancy Hepp, MS past Lead Researcher

Reviewer

Last update: December 19, 2025

Last full literature review: March 2025

CancerChoices provides information about integrative in cancer care, a patient-centered approach combining the best of conventional care, self care and evidence-informed complementary care in an integrated plan cancer care. We review complementaryin cancer care, complementary care involves the use of therapies intended to enhance or add to standard conventional treatments; examples include supplements, mind-body approaches such as yoga or psychosocial therapy, and acupuncture therapies and self-care lifestyle actions and behaviors that may impact cancer outcomes; examples include eating health-promoting foods, limiting alcohol, increasing physical activity, and managing stress practices to help patients and professionals explore and integrate the best combination of conventionalthe cancer care offered by conventionally trained physicians and most hospitals; examples are chemotherapy, surgery, and radiotherapy and complementary therapies and practices for each person.

Our staff have no financial conflicts of interest to declare. We receive no funds from any manufacturers or retailers gaining financial profit by promoting or discouraging therapies mentioned on this site.

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