StressNCT07475858
Photobiomodulation, Heart Rate Variability, and Acute Stress
A study testing Vielight Vagus in people with Stress, run by Brigham and Women's Hospital.
Trial summary
Photobiomodulation (PBM) is a form of light therapy that uses red or near-infrared light to influence biological processes. In prior studies, PBM has been shown to improve various physiological functions, including tissue repair, inflammation, and cognitive performance. Read more about this study
- Who is it for?
- Ages 18 to 64 yearsHealthy volunteers can take part
- Conditions the study is for
- Stress
- What is being tested?
- Vielight Vagus
- Type of treatment
- Medical device
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 40 participants
- Where
- No sites listed yet
- Study dates
- 1 Nov 2026to 31 Aug 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 64 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy adults, aged 18-64 years
- Ability to read and understand English
- Willing to comply with the study procedures and attend all scheduled sessions
Who cannot join
- Taking medications that could significantly influence autonomic function
- Presence or history of any serious cardiovascular, inflammatory, and pain conditions as well as neurological disorders or other conditions that affect the central nervous system
- Pregnant
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: The Effect of Photobiomodulation on Heart Rate Variability in Healthy Adults Subjected to the Maastricht Acute Stress Test (MAST): A Sham-controlled, Within-subject Study
Photobiomodulation (PBM) is a form of light therapy that uses red or near-infrared light to influence biological processes. In prior studies, PBM has been shown to improve various physiological functions, including tissue repair, inflammation, and cognitive performance. However, little is known about its impact on autonomic nervous system regulation. Thus, the goal of this study is to evaluate the effects of PBM on vagal activity, as measured by heart rate variability (HRV), in healthy adults undergoing experimental stress.
Read the detailed description
Photobiomodulation (PBM) is a non-invasive therapeutic technique that uses low-level light, typically in the red or near-infrared spectrum, to stimulate biological tissues. This approach has been increasingly studied for its beneficial effects on wound healing, mood, and sleep quality. Recent research has also highlighted PBM's potential in enhancing brain function, neuroplasticity, and cognitive performance. For example, prior studies have demonstrated that transcranial PBM (i.e., PBM delivered to the head) can help modulate neuronal activity, improve cerebral blood flow, and promote neuroprotective effects for traumatic brain injury and stroke. Given these findings, PBM may also have potential for influencing autonomic function and stress physiology. However, to date, little is known about the effects of PBM on the autonomic nervous system, particularly its influence on vagal activity and heart rate variability (HRV).
This study aims to fill this gap by investigating the effects of transcutaneous cervical plus intranasal PBM on HRV in healthy individuals subjected to experimental stress. Specifically, the Maastricht Acute Stress Test (MAST) will be used, which is a validated stress protocol that has been shown to strongly and reliably induce acute autonomic stress responses. A within-subject design will be employed with four repeated visits per participant to examine the effects of both PBM and sham intervention applied before and after stress induction on vagal activity, as measured by HRV. As the first study to examine PBM's impact on HRV, this research will provide valuable insights into the potential of PBM as a novel, non-invasive approach to modulating autonomic regulation, particularly in the context of stress.
- Conditions
- Stress
- Being tested
- Vielight Vagus, Sham Vielight Vagus
- Keywords
- Photobiomodulation, Heart rate variability, Vagus nerve, Stress
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Vielight VagusDevice
In this study, PBM will be administered using a transcutaneous cervical plus intranasal PBM device (Vielight Vagus, Ontario, Canada). The transcutaneous component of the device is designed to be placed bilaterally over the lateral aspect of the neck and delivers an irradiance of 810nm at 50mW/cm2, while the intranasal component is designed to be inserted into the nasal cavity and provides an irradiance of 810nm at 25mW/cm2. The pulse frequency will be set to 100 Hz and 50% duty cycle.
Sham Vielight VagusOther
For sham intervention, the same PBM device will be placed on the participants in the same manner, but without emitting light to ensure blinding of the intervention.
| Study group | Role | What they receive |
|---|---|---|
| Real PBM before stress induction | Active comparator | After a 5-minute baseline measurement, participants will receive 20 minutes of real PBM. They will then complete the 15-minute MAST protocol (stress induction) and be monitored for additional 10 minutes to assess recovery from stress. Receives: Device: Vielight Vagus |
| Sham PBM before stress induction | Sham comparator | After a 5-minute baseline measurement, participants will receive 20 minutes of sham PBM. They will then complete the 15-minute MAST protocol (stress induction) and be monitored for additional 10 minutes to assess recovery from stress. Receives: Other: Sham Vielight Vagus |
| Real PBM after stress induction | Active comparator | After a 5-minute baseline measurement, participants will undergo the 15-minute MAST protocol (stress induction), followed by 20 minutes of real PBM and 10 minutes of post-intervention period. Receives: Device: Vielight Vagus |
| Sham PBM after stress induction | Sham comparator | After a 5-minute baseline measurement, participants will undergo the 15-minute MAST protocol (stress induction), followed by 20 minutes of sham PBM and 10 minutes of post-intervention period. Receives: Other: Sham Vielight Vagus |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in HRV, as measured by RMSSD
Root mean square of successive differences (RMSSD) is a commonly used time-domain measure of HRV. It is commonly used to assess autonomic regulation, with higher RMSSD indicating greater parasympathetic activity and vagal tone. In this study, RMSSD will be calculated for every 5-minute segments of HRV data from baseline to post-phase. The area under the curve (AUC) will be computed to assess changes in RMSSD values with respect to baseline. This approach will allow for a comprehensive evaluation of changes in parasympathetic activity, in both magnitude and variability over time under different experimental conditions. Paired t-tests will then be used to compare AUCs between PBM and sham interventions, separately for before and after stress induction.
Measured: 50 minutes
Secondary outcomes (3)
Change in electrodermal activity (EDA)
Similar to ECG/HRV, EDA data will be measured continuously from baseline to post-phase for 50 minutes, to provide a more comprehensive assessment of the autonomic responses.
Measured: 50 minutes
Change in blood pressure (BP)
BP will be assessed every 5 minutes during each visit's study procedures.
Measured: 50 minutes
Change in state anxiety
Participants will be asked to complete the state anxiety subscale of the State-Trait Anxiety Inventory (STAI) two times for each visit, initially before baseline and then during the post-phase period.
Measured: 50 minutes
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Mar 2026
- Study start1 Nov 2026 (estimated)
- Primary completion31 May 2027 (estimated)
- Study completion31 Aug 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for StressStudies of the same condition, open and under way.
- More trials run by Brigham and Women's HospitalThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- This study will employ a within-subject, counterbalanced design to assess the effects of PBM on HRV. All participants will complete four testing visits. Each visit will involve the use of the MAST protocol to induce acute autonomic stress response under different conditions of PBM administration. The four conditions will be: 1) Real PBM before MAST; 2) Sham PBM before MAST; 3) Real PBM after MAST; and 4) Sham PBM after MAST. Participants will be randomly assigned to a counterbalanced order of these four conditions to control for order effects, and the visits will be spaced at least one week apart to minimize carryover effects between conditions.
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 40 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Brigham and Women's Hospital
- Sponsor type
- University, hospital or other
- Collaborators
- Vielight Inc.
- Responsible party
- Principal investigator, Peter M. Wayne, Ph.D., Brigham and Women's Hospital
- Investigators
- Peter Wayne, Principal investigator, Brigham and Women's Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07475858
- Sponsor's protocol ID
- 2026P000281
- Status last verified
- Sep 2026
- First submitted
- 13 Mar 2026
- Last updated
- 24 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 24 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect of Photobiomodulation on Heart Rate Variability in Healthy Adults Subjected to the Maastricht Acute Stress Test (MAST): A Sham-controlled, Within-subject Study
- ClinicalTrials.gov ID
- NCT07475858
- Acronym / sponsor ID
- 2026P000281
- Conditions
- Stress
- Keywords
- Photobiomodulation, Heart rate variability, Vagus nerve, Stress
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- Brigham and Women's HospitalUniversity, hospital or other
- Collaborators
- Vielight Inc.
- Study start
- 1 Nov 2026 (estimated)
- Primary completion
- 31 May 2027 (estimated)
- Study completion
- 31 Aug 2027 (estimated)
- First posted
- 17 Mar 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Photobiomodulation (PBM) is a form of light therapy that uses red or near-infrared light to influence biological processes. In prior studies, PBM has been shown to improve various physiological functions, including tissue repair, inflammation, and cognitive performance. However, little is known about its impact on autonomic nervous system regulation. Thus, the goal of this study is to evaluate the effects of PBM on vagal activity, as measured by heart rate variability (HRV), in healthy adults undergoing experimental stress.
Detailed description
Photobiomodulation (PBM) is a non-invasive therapeutic technique that uses low-level light, typically in the red or near-infrared spectrum, to stimulate biological tissues. This approach has been increasingly studied for its beneficial effects on wound healing, mood, and sleep quality. Recent research has also highlighted PBM's potential in enhancing brain function, neuroplasticity, and cognitive performance. For example, prior studies have demonstrated that transcranial PBM (i.e., PBM delivered to the head) can help modulate neuronal activity, improve cerebral blood flow, and promote neuroprotective effects for traumatic brain injury and stroke. Given these findings, PBM may also have potential for influencing autonomic function and stress physiology. However, to date, little is known about the effects of PBM on the autonomic nervous system, particularly its influence on vagal activity and heart rate variability (HRV).
This study aims to fill this gap by investigating the effects of transcutaneous cervical plus intranasal PBM on HRV in healthy individuals subjected to experimental stress. Specifically, the Maastricht Acute Stress Test (MAST) will be used, which is a validated stress protocol that has been shown to strongly and reliably induce acute autonomic stress responses. A within-subject design will be employed with four repeated visits per participant to examine the effects of both PBM and sham intervention applied before and after stress induction on vagal activity, as measured by HRV. As the first study to examine PBM's impact on HRV, this research will provide valuable insights into the potential of PBM as a novel, non-invasive approach to modulating autonomic regulation, particularly in the context of stress.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (participant)
- Number of arms
- 4
- Model description
- This study will employ a within-subject, counterbalanced design to assess the effects of PBM on HRV. All participants will complete four testing visits. Each visit will involve the use of the MAST protocol to induce acute autonomic stress response under different conditions of PBM administration. The four conditions will be: 1) Real PBM before MAST; 2) Sham PBM before MAST; 3) Real PBM after MAST; and 4) Sham PBM after MAST. Participants will be randomly assigned to a counterbalanced order of these four conditions to control for order effects, and the visits will be spaced at least one week apart to minimize carryover effects between conditions.
| Arm | Type | Receives |
|---|---|---|
| Real PBM before stress induction | Active comparator | Device: Vielight VagusAfter a 5-minute baseline measurement, participants will receive 20 minutes of real PBM. They will then complete the 15-minute MAST protocol (stress induction) and be monitored for additional 10 minutes to assess recovery from stress. |
| Sham PBM before stress induction | Sham comparator | Other: Sham Vielight VagusAfter a 5-minute baseline measurement, participants will receive 20 minutes of sham PBM. They will then complete the 15-minute MAST protocol (stress induction) and be monitored for additional 10 minutes to assess recovery from stress. |
| Real PBM after stress induction | Active comparator | Device: Vielight VagusAfter a 5-minute baseline measurement, participants will undergo the 15-minute MAST protocol (stress induction), followed by 20 minutes of real PBM and 10 minutes of post-intervention period. |
| Sham PBM after stress induction | Sham comparator | Other: Sham Vielight VagusAfter a 5-minute baseline measurement, participants will undergo the 15-minute MAST protocol (stress induction), followed by 20 minutes of sham PBM and 10 minutes of post-intervention period. |
Who may qualify
- Ages
- 18 to 64 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- Healthy adults, aged 18-64 years
- Ability to read and understand English
- Willing to comply with the study procedures and attend all scheduled sessions
Key exclusion criteria (3 listed)
- Taking medications that could significantly influence autonomic function
- Presence or history of any serious cardiovascular, inflammatory, and pain conditions as well as neurological disorders or other conditions that affect the central nervous system
- Pregnant
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Vielight VagusIn this study, PBM will be administered using a transcutaneous cervical plus intranasal PBM device (Vielight Vagus, Ontario, Canada). The transcutaneous component of the device is designed to be placed bilaterally over the lateral aspect of the neck and delivers an irradiance of 810nm at 50mW/cm2, while the intranasal component is designed to be inserted into the nasal cavity and provides an irradiance of 810nm at 25mW/cm2. The pulse frequency will be set to 100 Hz and 50% duty cycle. | Device | Real PBM after stress induction, Real PBM before stress induction |
| Sham Vielight VagusFor sham intervention, the same PBM device will be placed on the participants in the same manner, but without emitting light to ensure blinding of the intervention. | Other | Sham PBM after stress induction, Sham PBM before stress induction |
Primary outcome
Change in HRV, as measured by RMSSD
Time frame: 50 minutes
Root mean square of successive differences (RMSSD) is a commonly used time-domain measure of HRV. It is commonly used to assess autonomic regulation, with higher RMSSD indicating greater parasympathetic activity and vagal tone. In this study, RMSSD will be calculated for every 5-minute segments of HRV data from baseline to post-phase. The area under the curve (AUC) will be computed to assess changes in RMSSD values with respect to baseline. This approach will allow for a comprehensive evaluation of changes in parasympathetic activity, in both magnitude and variability over time under different experimental conditions. Paired t-tests will then be used to compare AUCs between PBM and sham interventions, separately for before and after stress induction.
3 secondary outcomes
Change in electrodermal activity (EDA)
Time frame: 50 minutes
Change in blood pressure (BP)
Time frame: 50 minutes
Change in state anxiety
Time frame: 50 minutes
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 24 Sep 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Peter Wayne principal investigator
Brigham and Women's Hospital
Questions about this trial
What is this clinical trial studying?
A study testing Vielight Vagus in people with Stress, run by Brigham and Women's Hospital.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 24 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Peter Wayne, PhD (617-732-6271, pwyane@bwh.harvard.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in HRV, as measured by RMSSD (time frame: 50 minutes). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 24 Sep 2026; AzTrials last refreshed its copy on 6 Nov 2026.