RecruitingNCT07325851EPOOzo-2Updated Sep 23, 2026

Patients Referred to the Chronic Pain Unit for Palliative Treatment With Ozone Therapy Between 2026 and 2029.

An observational study in Chemotherapy-Induced Peripheral Neuropathy, Radiation Toxicity and Chronic Pain, sponsored by Bernardino Clavo, MD, PhD. Recruiting at 1 site in Spain. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-23.

Sponsored by Bernardino Clavo, MD, PhD · Observational

From the registry’s dates

Started Jan 2026; still recruiting 9 months later.

Study type: Observational
Model: Case-only
Time perspective: Prospective
Enrollment: 120
Ages: 18 Years and older
Sex: All

Study summary

The main objective of this study is to analyze the impact on the health-related quality of life of patients with refractory symptoms who have been referred to the Dr. Negrín University Hospital Chronic Pain Unit for adjuvant palliative treatment with ozone therapy between January 2026 and December 2029. Additionally, the study aims to evaluate several specific symptoms, hyperspectral and thermal images, non-invasive clinical parameters related to the Autonomic Nervous System (such as heart rate variability, electrochemical skin conductance, and vibration perception thresholds), oxidative stress and inflammatory parameters, and gut microbiota composition.

Read the detailed description

Patients are referred to the Chronic Pain Unit in the absence or failure of standard treatment, or when the standard treatment is associated with high morbidity or high risk. Frequently, these patients present alterations in self-perceived health-related quality of life (HRQoL), anxiety, depression, and other symptoms such as radiation-induced pelvic toxicity or chemotherapy-induced peripheral neuropathy (CIPN).

This prospective observational study (EPOOzo-2) aims to evaluate the effect of adjuvant symptomatic/palliative ozone therapy on HRQoL and potential changes from baseline. Specifically, it incorporates new non-invasive technologies to objectively assess microcirculation, neuropathy and autonomic regulation.

Main Objectives:

1. Analyze the impact on HRQoL of patients with refractory symptoms treated with ozone.

Secondary Objectives: Depending on the clinical case, analyze the impact of ozone treatment on: 2. Anxiety and depression. 3. Treated symptoms (e.g., pain, paresthesia). 4. Fatigue. 5. Toxicity grade (in cancer patients). 6. Non-invasive clinical parameters related to the Autonomic Nervous System (central and peripheral) and somatosensory function. 7. Biochemical parameters and gut microbiome analysis (in patients with systemic/rectal ozone).

Methodology: Prospective and observational study of patients referred for symptomatic/palliative ozone therapy between January 2026 and December 2029.

Assessments at weeks: 0 (baseline), 16 (end of O3/O2 treatment), 28 (12 weeks after the end of ozone), and 40 (24 weeks after the end of ozone).

Conditions studied

Chemotherapy-Induced Peripheral Neuropathy
Radiation Toxicity
Chronic Pain
Delayed Wound Healing
Refractory Symptoms

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Keywords

Ozone Therapy
Health-related quality of life
Chemotherapy-induced Peripheral Neuropathy
Radiation-induced toxicity
Hyperspectral imaging
Infrared imaging
Heart Rate Variability
Sudoscan
Vibrometry
Oxidative stress
Gut Microbiota
Anxiety and Depression

In context

Radiation Injuries

328 studies on the registry are indexed under Radiation Injuries; 96 are open to participants now.

This study's planned enrollment of 120 is close to the median of 130 across 96 observational studies indexed under Radiation Injuries.

Browse Radiation Injuries studies →

Lead sponsor

Bernardino Clavo, MD, PhD is the lead sponsor of 10 studies on the registry; 6 are open to participants now.

Counted across the registry records on this site, refreshed daily.

Who can participate

Ages eligible: 18 Years and older
Sexes eligible: All
Accepts healthy volunteers: No
Sampling method: Non-probability sample

Study population

Patients submitted to the Chronic Pain Unit of the Hospital Universitario de Gran Canaria Dr. Negrín, between January 2026 and December 2029, for symptomatic/palliative treatment with ozone therapy because standard treatment does not exist, it has been unsuccessful, or it is associated with high risk or high morbidity.

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

1. Adults ≥ 18 years old.
2. Patients referred to the Chronic Pain Unit of the Dr. Negrín University Hospital for symptomatic/palliative treatment with ozone therapy because conventional treatment does not exist, has failed, has offered insufficient results, or is associated with high risk/morbidity.
3. After evaluation of symptoms and patients, it exists a potential benefit of adding ozone treatment to the current treatment.
4. Patients have no for ozone treatment.
5. Patients must sign the specific for this study and for the ozone treatment.

Exclusion criteria

Exclusion Criteria:

1. Age \< 18 years old.
2. Psychiatric illness or social situations that would limit compliance with study requirements.

or disability to attend scheduled treatments.

3. Contraindication or disability to attend scheduled treatments.
4. Uncontrolled clinical conditions (e.g., severe heart failure, massive hemorrhage, status epilepticus).
5. \< 6 months.
6. Known allergy to ozone.
7. Hemochromatosis (for systemic ozone treatment).
8. Pregnancy (for systemic ozone treatment).
9. Significant Glucose-6-Phosphate Dehydrogenase deficiency (Favism) (for systemic ozone treatment).
10. Patients who do not meet the inclusion criteria.

Terms in these criteria, in plain language(3)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Contraindication

A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Life expectancy

The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.

Study design

Observational model: Case-only
Time perspective: Prospective
Enrollment: 120 participants (estimated)
Target follow-up: 40 Weeks
Patient registry: Yes
Biospecimen retention: Samples with dna

Groups and cohorts

Ozone Group
Patients with refractory symptoms referred for palliative treatment with ozone therapy between 2026 and 2029.
Procedure: Ozone Therapy

Interventions

ProcedureOzone Therapy
Systemic (rectal, autohemotherapy) and/or local ozone administration (cutaneous, intravaginal, intravesical). Dosage, frequency, and duration will depend on the symptoms treated and clinical evolution. Usually planned 40 sessions over 4 months.
Also known as: Ozone Treatment

What researchers measure

Primary outcomes

Change from Baseline in Health-Related Quality of Life by the "EQ-5D-5L" Questionnaire (at the end of ozone therapy).
Self-reported evaluation of 5 physical and emotional items scored in five levels, plus a Visual Analog Scale (EQ-VAS) from 0 (worst health) to 100 (best health).
Time frame: At the end of ozone therapy (approx. week 16).

Secondary outcomes

Change from Baseline in Health-Related Quality of Life by the "EQ-5D-5L" Questionnaire (at 12 weeks after the end of ozone therapy).
Self-reported evaluation of 5 physical and emotional items scored in five levels, plus a Visual Analog Scale (EQ-VAS) from 0 (worst health) to 100 (best health).
Time frame: At 12 weeks after the end of ozone therapy (approx. week 28).
Change from Baseline in Health-Related Quality of Life by the "EQ-5D-5L" Questionnaire (at 24 weeks after the end of ozone therapy).
Self-reported evaluation of 5 physical and emotional items scored in five levels, plus a Visual Analog Scale (EQ-VAS) from 0 (worst health) to 100 (best health).
Time frame: At 24 weeks after the end of ozone therapy (approx. week 40).
Change from Baseline in Anxiety and Depression Levels (HAD Scale) (at the end of ozone therapy).
Hospital Anxiety and Depression Scale (HADS). Scores range from 0 to 21 for each subscale, where higher scores indicate worse anxiety or depression.
Time frame: At the end of ozone therapy (approx. week 16).
Change from Baseline in Anxiety and Depression Levels (HAD Scale) (at 12 weeks after the end of ozone therapy).
Hospital Anxiety and Depression Scale (HADS). Scores range from 0 to 21 for each subscale, where higher scores indicate worse anxiety or depression.
Time frame: At 12 week after the end of ozone therapy (approx. week 28).
Change from Baseline in Anxiety and Depression Levels (HAD Scale) (at 24 weeks after the end of ozone therapy).
Hospital Anxiety and Depression Scale (HADS). Scores range from 0 to 21 for each subscale, where higher scores indicate worse anxiety or depression.
Time frame: At 24 week after the end of ozone therapy (approx. week 40).
Change from Baseline in Health-Related Quality of Life by the "QLQ-C30" Questionnaire (only in cancer patients). (At the end of ozone therapy).
The EORTC QLQ-C30 is a 30-item questionnaire that includes five functional scales (physical, role, emotional, cognitive, and social), three symptom scales (fatigue, nausea and vomiting, and pain), a global health status scale, and several single items. Scores are transformed to a 0-100 scale. For functional and global health scales, higher scores represent better functioning or quality of life. For symptom scales/items, higher scores indicate greater symptomatology or problems
Time frame: At the end of ozone therapy (approx. week 16).
Change from Baseline in Health-Related Quality of Life by the "QLQ-C30" Questionnaire (only in cancer patients). (At 12 weeks after the end of ozone therapy).
The EORTC QLQ-C30 is a 30-item questionnaire that includes five functional scales (physical, role, emotional, cognitive, and social), three symptom scales (fatigue, nausea and vomiting, and pain), a global health status scale, and several single items. Scores are transformed to a 0-100 scale. For functional and global health scales, higher scores represent better functioning or quality of life. For symptom scales/items, higher scores indicate greater symptomatology or problems
Time frame: At 12 weeks after the end of ozone therapy (approx. week 28).
Change from Baseline in Health-Related Quality of Life by the "QLQ-C30" Questionnaire (only in cancer patients). (At 24 weeks after the end of ozone therapy).
The EORTC QLQ-C30 is a 30-item questionnaire that includes five functional scales (physical, role, emotional, cognitive, and social), three symptom scales (fatigue, nausea and vomiting, and pain), a global health status scale, and several single items. Scores are transformed to a 0-100 scale. For functional and global health scales, higher scores represent better functioning or quality of life. For symptom scales/items, higher scores indicate greater symptomatology or problems
Time frame: At 24 weeks after the end of ozone therapy (approx. week 40).
Change from Baseline in Fatigue (Chalder Fatigue Scale and/or EORTC QLQ-FA12 for cancer patients) (at the end of ozone therapy).
Assessed using the Chalder Fatigue Scale (CFQ-11) and/or EORTC QLQ-FA12 for cancer patients. Higher scores indicate greater fatigue
Time frame: At the end of ozone therapy (approx. week 16).
Change from Baseline in Fatigue (Chalder Fatigue Scale and/or EORTC QLQ-FA12 for cancer patients) (at 12 weeks after the end of ozone therapy).
Assessed using the Chalder Fatigue Scale (CFQ-11) and/or EORTC QLQ-FA12 for cancer patients. Higher scores indicate greater fatigue
Time frame: At 12 weeks after the end of ozone therapy (approx. week 28).
Change from Baseline in Fatigue (Chalder Fatigue Scale and/or EORTC QLQ-FA12 for cancer patients) (at 24 weeks after the end of ozone therapy).
Assessed using the Chalder Fatigue Scale (CFQ-11) and/or EORTC QLQ-FA12 for cancer patients. Higher scores indicate greater fatigue
Time frame: At 24 weeks after the end of ozone therapy (approx. week 40).
Change from Baseline in Pain Score (Visual Analog Scale), (at the end of ozone therapy).
Self-reported evaluation of pain severity using a Visual Analog Scale (VAS), scored from 0 ("No pain") to 10 ("Pain as bad as you can imagine").
Time frame: At the end of ozone therapy (approx. week 16).
Change from Baseline in Pain Score (Visual Analog Scale), (at 12 weeks after the end of ozone therapy).
Self-reported evaluation of pain severity using a Visual Analog Scale (VAS), scored from 0 ("No pain") to 10 ("Pain as bad as you can imagine").
Time frame: At 12 weeks after the end of ozone therapy (approx. week 28).
Change from Baseline in Pain Score (Visual Analog Scale), (at 24 weeks after the end of ozone therapy).
Self-reported evaluation of pain severity using a Visual Analog Scale (VAS), scored from 0 ("No pain") to 10 ("Pain as bad as you can imagine").
Time frame: At 24 weeks after the end of ozone therapy (approx. week 40).
Change from Baseline in the grade of toxicity secondary to cancer-treatment (if applicable) according to the CTCAE v5.0 scale, (at the end of ozone therapy).
Grade of toxicity secondary to cancer-treatment according to the CTCAE v5.0 (Common Terminology Criteria for Adverse Events from the National Cancer Institute) scale. Each toxicity is usually scored from 0 (asymptomatic or mild symptoms) to 5 (death).
Time frame: At the end of ozone therapy (approx. week 16).
Change from Baseline in the grade of toxicity secondary to cancer-treatment (if applicable) according to the CTCAE v5.0 scale, (at 12 weeks after the end of ozone therapy).
Grade of toxicity secondary to cancer-treatment according to the CTCAE v5.0 (Common Terminology Criteria for Adverse Events from the National Cancer Institute) scale. Each toxicity is usually scored from 0 (asymptomatic or mild symptoms) to 5 (death).
Time frame: At 12 weeks after the end of ozone therapy (approx. week 28).
Change from Baseline in the grade of toxicity secondary to cancer-treatment (if applicable) according to the CTCAE v5.0 scale, (at 24 weeks after the end of ozone therapy).
Grade of toxicity secondary to cancer-treatment according to the CTCAE v5.0 (Common Terminology Criteria for Adverse Events from the National Cancer Institute) scale. Each toxicity is usually scored from 0 (asymptomatic or mild symptoms) to 5 (death).
Time frame: At 24 weeks after the end of ozone therapy (approx. week 40).
Change from Baseline in Electrochemical Skin Conductance (Sudoscan), (at the end of ozone therapy).
Non-invasive evaluation of sudomotor function (small fiber neuropathy assessment). Measured in microsiemens (µS) on hands and feet using SUDOSCAN technology.
Time frame: At the end of ozone therapy (approx. week 16).
Change from Baseline in Electrochemical Skin Conductance (Sudoscan), (at 12 weeks after the end of ozone therapy).
Non-invasive evaluation of sudomotor function (small fiber neuropathy assessment). Measured in microsiemens (µS) on hands and feet using SUDOSCAN technology.
Time frame: At 12 weeks after the end of ozone therapy (approx. week 28).
Change from Baseline in Vibration Perception Thresholds (Multifrequency Vibrometry), (at the end of ozone therapy).
Assessment of large fiber nerve function using the VibroSense Meter II. Measures perception thresholds at different frequencies (e.g., 4Hz to 500Hz).
Time frame: At the end of ozone therapy (approx. week 16).
Change from Baseline in Vibration Perception Thresholds (Multifrequency Vibrometry), (at 12 weeks after the end of ozone therapy).
Assessment of large fiber nerve function using the VibroSense Meter II. Measures perception thresholds at different frequencies (e.g., 4Hz to 500Hz).
Time frame: At 12 weeks after the end of ozone therapy (approx. week 28).
Change from Baseline in Postural Stability (Equilibrium Platform), (at the end of ozone therapy).
Functional assessment of balance and Center of Pressure (CoP) displacement using specific force platforms.
Time frame: At the end of ozone therapy (approx. week 16).
Change from Baseline in Postural Stability (Equilibrium Platform), (at 12 weeks after the end of ozone therapy).
Functional assessment of balance and Center of Pressure (CoP) displacement using specific force platforms.
Time frame: At 12 weeks after the end of ozone therapy (approx. week 28).
Change from Baseline in Heart Rate Variability (HRV), (at the end of ozone therapy).
Non-invasive assessment of the Autonomic Nervous System (vagal tone) by analyzing time intervals between heartbeats (RR intervals).
Time frame: At the end of ozone therapy (approx. week 16).
Change from Baseline in Heart Rate Variability (HRV), (at 12 weeks after the end of ozone therapy).
Non-invasive assessment of the Autonomic Nervous System (vagal tone) by analyzing time intervals between heartbeats (RR intervals).
Time frame: At 12 weeks after the end of ozone therapy (approx. week 28).
Changes from baseline in Hyperspectral signatures and Infrared images obtained from hands and feet at the end of follow-up, (at the end of ozone therapy).
Assessment of the percentage of reflectance for each wavelength of the hyperspectral and infrared images obtained with specific devices.
Time frame: At the end of ozone therapy (approx. week 16).
Changes from baseline in Hyperspectral signatures and Infrared images obtained from hands and feet at the end of follow-up, (at 12 weeks after the end of ozone therapy).
Assessment of the percentage of reflectance for each wavelength of the hyperspectral and infrared images obtained with specific devices.
Time frame: At 12 weeks after the end of ozone therapy (approx. week 28).
Changes from baseline in biochemical parameters of oxidative stress and inflammation (at the end of ozone therapy).
Changes in serum levels of oxidative stress parameters (superoxide dismutase, glutathione, glutathione peroxidase, and free radicals) and proinflammatory cytokines.
Time frame: At the end of ozone therapy (approx. week 16).
Changes from baseline in biochemical parameters of oxidative stress and inflammation (at 12 weeks after the end of ozone therapy).
Changes in serum levels of oxidative stress parameters (superoxide dismutase, glutathione, glutathione peroxidase, and free radicals) and proinflammatory cytokines.
Time frame: At 12 weeks after the end of ozone therapy (approx. week 28).
Change from Baseline in Gut Microbiota Composition (at the end of ozone therapy).
Analysis of stool samples to evaluate changes in the intestinal microbiome (in patients treated with rectal ozone).
Time frame: At the end of ozone therapy (approx. week 16).
Change from Baseline in Gut Microbiota Composition (at 12 weeks after the end of ozone therapy).
Analysis of stool samples to evaluate changes in the intestinal microbiome (in patients treated with rectal ozone).
Time frame: At 12 weeks after the end of ozone therapy (approx. week 28).

Study locations

1 of 1 sites recruiting

Dr. Negrín University Hospital
Las Palmas de Gran Canaria, Las Palmas 35019, Spain
Recruiting
- Bernardino Clavo, MD, PhD · Contact · bernardinoclavo@gmail.com · +34 928449278
- Francisco Rodríguez-Esparragón, BSc, PhyD · Contact · afrodesp@gmail.com · +34 928449288
Recruiting

References and documents

Publications

Clavo B, Cordoba-Lanus E, Martinez-Sanchez G, Federico M, Canovas-Molina A, Pinero JE, Vargas-Prado AM, Ramchandani A, Zajac M, Ribeiro I, Navarro M, Jorge IJ, Gonzalez-Martin JM, Martin-Alfaro R, Fernandez-Tagarro M, Diaz-Garrido JA, Lorenzo-Morales J, Rodriguez-Esparragon F. Modulating the Gut Microbiota via Rectal Ozone Insufflation in Gynecological Cancer Patients with Radiotherapy/Chemotherapy-Induced Pelvic Toxicity: A Proposed Clinical Study Protocol. J Clin Med. 2025 Nov 12;14(22):8015. doi: 10.3390/jcm14228015. PubMed 41303051 ↗
Clavo B, Canovas-Molina A, Federico M, Martinez-Sanchez G, Benitez G, Galvan S, Ramallo-Farina Y, Fabelo H, Cazorla-Rivero S, Lago-Moreno E, Antonilli C, Diaz-Garrido JA, Jorge IJ, Marrero-Callico G, Rodriguez-Abreu D, Rodriguez-Esparragon F. Ozone Treatment in the Management of Chemotherapy-Induced Peripheral Neuropathy: A Review of Rationale and Research Directions. Cancers (Basel). 2025 Jul 8;17(14):2278. doi: 10.3390/cancers17142278. PubMed 40723162 ↗
Bisshopp S, Linertova R, Carames MA, Szolna A, Jorge IJ, Navarro M, Melchiorsen B, Rodriguez-Diaz B, Gonzalez-Martin JM, Clavo B. Pain Relief, Disability, and Hospital Costs After Intradiscal Ozone Treatment or Microdiscectomy for Lumbar Disc Herniation: A 24-Month Real-World Prospective Study. J Clin Med. 2025 Jun 26;14(13):4534. doi: 10.3390/jcm14134534. PubMed 40648907 ↗
Clavo B, Canovas-Molina A, Garcia-Lourve C, Cazorla-Rivero S, Federico M, Rodriguez-Esparragon F. Effects of ozone treatment on chemotherapy-induced peripheral neuropathy: a promising research area. Med Gas Res. 2025 Jun 1;15(2):195-197. doi: 10.4103/mgr.MEDGASRES-D-24-00074. Epub 2025 Jan 18. No abstract available. PubMed 40070187 ↗
Clavo B, Rodriguez-Abreu D, Galvan-Ruiz S, Federico M, Canovas-Molina A, Ramallo-Farina Y, Antonilli C, Benitez G, Fabelo H, Garcia-Lourve C, Gonzalez-Beltran D, Jorge IJ, Rodriguez-Esparragon F, Callico GM. Long-Term Effects of Ozone Treatment in Patients with Persistent Numbness and Tingling Secondary to Chemotherapy-Induced Peripheral Neuropathy. A Retrospective Study. Integr Cancer Ther. 2025 Jan-Dec;24:15347354241307038. doi: 10.1177/15347354241307038. PubMed 39797612 ↗
Clavo B, Canovas-Molina A, Diaz-Garrido JA, Canas S, Ramallo-Farina Y, Laffite H, Federico M, Rodriguez-Abreu D, Galvan S, Garcia-Lourve C, Gonzalez-Beltran D, Carames MA, Hernandez-Fleta JL, Serrano-Aguilar P, Rodriguez-Esparragon F. Effects of ozone therapy on anxiety and depression in patients with refractory symptoms of severe diseases: a pilot study. Front Psychol. 2023 Aug 4;14:1176204. doi: 10.3389/fpsyg.2023.1176204. eCollection 2023. PubMed 37599784 ↗
Clavo B, Rodriguez-Abreu D, Galvan S, Federico M, Martinez-Sanchez G, Ramallo-Farina Y, Antonelli C, Benitez G, Rey-Baltar D, Jorge IJ, Rodriguez-Esparragon F, Serrano-Aguilar P. Long-term improvement by ozone treatment in chronic pain secondary to chemotherapy-induced peripheral neuropathy: A preliminary report. Front Physiol. 2022 Aug 30;13:935269. doi: 10.3389/fphys.2022.935269. eCollection 2022. PubMed 36111149 ↗
Clavo B, Canovas-Molina A, Ramallo-Farina Y, Federico M, Rodriguez-Abreu D, Galvan S, Ribeiro I, Marques da Silva SC, Navarro M, Gonzalez-Beltran D, Diaz-Garrido JA, Cazorla-Rivero S, Rodriguez-Esparragon F, Serrano-Aguilar P. Effects of Ozone Treatment on Health-Related Quality of Life and Toxicity Induced by Radiotherapy and Chemotherapy in Symptomatic Cancer Survivors. Int J Environ Res Public Health. 2023 Jan 13;20(2):1479. doi: 10.3390/ijerph20021479. PubMed 36674232 ↗
Clavo B, Gutierrez D, Martin D, Suarez G, Hernandez MA, Robaina F. Intravesical ozone therapy for progressive radiation-induced hematuria. J Altern Complement Med. 2005 Jun;11(3):539-41. doi: 10.1089/acm.2005.11.539. PubMed 15992242 ↗
Clavo B, Suarez G, Aguilar Y, Gutierrez D, Ponce P, Cubero A, Robaina F, Carreras JL. Brain ischemia and hypometabolism treated by ozone therapy. Forsch Komplementmed. 2011;18(5):283-7. doi: 10.1159/000333795. Epub 2011 Oct 13. PubMed 22105041 ↗
Clavo B, Ceballos D, Gutierrez D, Rovira G, Suarez G, Lopez L, Pinar B, Cabezon A, Morales V, Oliva E, Fiuza D, Santana-Rodriguez N. Long-term control of refractory hemorrhagic radiation proctitis with ozone therapy. J Pain Symptom Manage. 2013 Jul;46(1):106-12. doi: 10.1016/j.jpainsymman.2012.06.017. Epub 2012 Oct 26. PubMed 23102757 ↗
Clavo B, Santana-Rodriguez N, Gutierrez D, Lopez JC, Suarez G, Lopez L, Robaina F, Bocci V. Long-term improvement in refractory headache following ozone therapy. J Altern Complement Med. 2013 May;19(5):453-8. doi: 10.1089/acm.2012.0273. Epub 2012 Dec 7. PubMed 23215625 ↗
Clavo B, Santana-Rodriguez N, Llontop P, Gutierrez D, Ceballos D, Mendez C, Rovira G, Suarez G, Rey-Baltar D, Garcia-Cabrera L, Martinez-Sanchez G, Fiuza D. Ozone Therapy in the Management of Persistent Radiation-Induced Rectal Bleeding in Prostate Cancer Patients. Evid Based Complement Alternat Med. 2015;2015:480369. doi: 10.1155/2015/480369. Epub 2015 Aug 18. PubMed 26357522 ↗
Clavo B, Santana-Rodriguez N, Llontop P, Gutierrez D, Suarez G, Lopez L, Rovira G, Martinez-Sanchez G, Gonzalez E, Jorge IJ, Perera C, Blanco J, Rodriguez-Esparragon F. Ozone Therapy as Adjuvant for Cancer Treatment: Is Further Research Warranted? Evid Based Complement Alternat Med. 2018 Sep 9;2018:7931849. doi: 10.1155/2018/7931849. eCollection 2018. PubMed 30271455 ↗
Clavo B, Rodriguez-Esparragon F, Rodriguez-Abreu D, Martinez-Sanchez G, Llontop P, Aguiar-Bujanda D, Fernandez-Perez L, Santana-Rodriguez N. Modulation of Oxidative Stress by Ozone Therapy in the Prevention and Treatment of Chemotherapy-Induced Toxicity: Review and Prospects. Antioxidants (Basel). 2019 Nov 26;8(12):588. doi: 10.3390/antiox8120588. PubMed 31779159 ↗
Clavo B, Navarro M, Federico M, Borrelli E, Jorge IJ, Ribeiro I, Rodriguez-Melcon JI, Carames MA, Santana-Rodriguez N, Rodriguez-Esparragon F. Ozone Therapy in Refractory Pelvic Pain Syndromes Secondary to Cancer Treatment: A New Approach Warranting Exploration. J Palliat Med. 2021 Jan;24(1):97-102. doi: 10.1089/jpm.2019.0597. Epub 2020 May 5. PubMed 32379556 ↗
Clavo B, Navarro M, Federico M, Borrelli E, Jorge IJ, Ribeiro I, Rodriguez-Melcon JI, Carames MA, Santana-Rodriguez N, Rodriguez-Esparragon F. Long-Term Results with Adjuvant Ozone Therapy in the Management of Chronic Pelvic Pain Secondary to Cancer Treatment. Pain Med. 2021 Sep 8;22(9):2138-2141. doi: 10.1093/pm/pnaa459. No abstract available. PubMed 33738491 ↗
Clavo B, Martinez-Sanchez G, Rodriguez-Esparragon F, Rodriguez-Abreu D, Galvan S, Aguiar-Bujanda D, Diaz-Garrido JA, Canas S, Torres-Mata LB, Fabelo H, Tellez T, Santana-Rodriguez N, Fernandez-Perez L, Marrero-Callico G. Modulation by Ozone Therapy of Oxidative Stress in Chemotherapy-Induced Peripheral Neuropathy: The Background for a Randomized Clinical Trial. Int J Mol Sci. 2021 Mar 10;22(6):2802. doi: 10.3390/ijms22062802. PubMed 33802143 ↗

Individual participant data

Plan to share: Yes — It will be available (after request): Individual participant data (IPD) that underlie the results reported in further articles, after deidentification Data will be available after publication, ending 36 months following the article publication. They will be available for investigators whose proposed use of the data has been approved by an independent review committee identified for this purpose

Supporting information: Study protocol, Informed consent form

Time frame: Data will be available after publication, ending 36 months following article publication.

Access criteria: They will be available for investigators whose proposed use of the data has been approved by an independent review committee identified for this purpose.

Updates

Tracking since Sep 25, 2026

No changes since tracking began. The registry record was last updated on Sep 23, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗

Registry details

Key details

Study ID: NCT07325851
Lead sponsor: Bernardino Clavo, MD, PhD
Collaborators: Hospital Universitario de Gran Canaria Doctor Negrín, Fundación Canaria Instituto de Investigación Sanitaria de Canarias, Complejo Hospitalario Universitario Insular Materno Infantil, University of Las Palmas de Gran Canaria, Council of Gran Canaria
Responsible party: Bernardino Clavo, MD, PhD (Principal Investigator, Research Unit Director, Hospital Universitario de Gran Canaria Doctor Negrín) — Sponsor-investigator
First posted: Jan 8, 2026
Start date: Jan 14, 2026
Primary completion: Dec 31, 2029 (estimated)
Completion: Jun 30, 2030 (estimated)
Last update: Sep 23, 2026

Study contacts

Bernardino Clavo, MD, PhD.

Contact

bernardinoclavo@gmail.com

+34 928449278

Francisco Rodríguez-Esparragón, BSc, PhyD

Contact

afrodesp@gmail.com

+34 928449288

Bernardino Clavo, MD, PhD

study chair · Dr. Negrín University Hospital, Las Palmas, Spain

Francisco Rodríguez-Esparragón, BSc, PhyD

principal investigator · Dr. Negrín University Hospital, Las Palmas, Spain

Ángeles Cánovas-Molina, RN

principal investigator · Dr. Negrín University Hospital, Las Palmas, Spain

Oversight

Data monitoring committee: No
FDA-regulated drug: No
FDA-regulated device: No

View the source record on ClinicalTrials.gov ↗

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