Pain, AcuteNCT06971315
Impact of Vitamin C on Pain Detection and Tolerance Threshold
A study testing Vitamin C in people with Pain, Acute, run by Centre Integre Universitaire de Sante et Services Sociaux du Nord de l'ile de Montreal at 1 site in Canada.
Trial summary
Non-opioid treatments are increasingly sought after for managing acute pain. Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) (e.g., Advil, Motrin, Naproxen) combined with acetaminophen (e.g., Tylenol) have become an alternative for relieving acute pain. Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Pain, Acute
- What is being tested?
- Vitamin C
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 38 participants
- Where
- 1 siteCanada
- Study dates
- 18 Jul 2025to 19 Dec 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Age ≥ 18 to 65 years old;
- No acute or chronic pain;
- No pain medication;
- French or English-speaking
Who cannot join
- Currently using vitamin C supplements;
- Pain in the last week or active cancer;
- Unavailable for follow-up;
- Allergy to milk (lactose in the placebo), or vitamin C,
- Treated with cyclosporine or warfarin (interaction with vitamin C);
- Pre-existing oxalate nephropathy, liver cirrhosis or hemochromatosis;
- Evidence of joint or overlying skin infection in the areas of testing.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Impact of Vitamin C on Pain Detection and Tolerance Threshold: a Double-blind Randomized Controlled Trial
Non-opioid treatments are increasingly sought after for managing acute pain. Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) (e.g., Advil, Motrin, Naproxen) combined with acetaminophen (e.g., Tylenol) have become an alternative for relieving acute pain. However, many patients cannot tolerate or have contraindications to NSAIDs and acetaminophen.
There is therefore an urgent need for studies evaluating the analgesic effects of vitamin C in the context of acute pain. Our study is conducted with healthy volunteer participants receiving either vitamin C or a placebo to assess the analgesic effect of vitamin C by comparing pain detection and tolerance thresholds.
Read the detailed description
Opioid-free treatments are increasingly sought for acute pain and NSAIDs have become an alternative to treat acute MSK pain and are often administered in addition to acetaminophen. However, NSAIDs can produce important adverse events and are contraindicated in many patients with comorbidities (e.g., heart disease, renal failure). Similarly, acetaminophen is contraindicated in patients with active liver disease or severe hepatic impairment.
Vitamin C has shown opioid sparing and anti-inflammatory effects mostly in postoperative contexts. Vitamin C has also demonstrated very low toxicity and rare contraindications at the dosage used in this study. Demonstrating that vitamin C increases pain detection and tolerance thresholds, thereby exhibiting an analgesic effect, could offer a valuable alternative or adjunct for patients who cannot tolerate or have contraindications to NSAIDs or acetaminophen, helping to reduce opioid use. With an aging population, the number of affected patients is expected to rise significantly.
The primary outcome is the pressure pain detection threshold (PPDT) measured with an algometer one to three hours after the last dose of the study drug (24 hours after the first dose of vitamin C or placebo).
Secondary outcomes are PPDT one to three hours after the first study drug dose, PPTT one to three hours after the initial dose and last dose of the study drug, and adverse events from the algometer or the vitamin C.
- Conditions
- Pain, Acute
- Being tested
- Vitamin C, Placebo
- Keywords
- Vitamin C, Algometer, Pain detection, Pain threshold
- Medical subject headings
- Acute Pain
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Vitamin CDietary supplement
Three doses of 900 mg vitamin C taken orally (baseline, 12 hours and 24 hours)
PlaceboOther
Three doses of 900 mg placebo taken orally (baseline, 12 hours and 24 hours)
| Study group | Role | What they receive |
|---|---|---|
| Vitamin C | Experimental | Three doses of 900 mg of vitamin C taken orally every 12 hours for 24 hours (baseline, 12 hours and 24 hours) Receives: Dietary Supplement: Vitamin C |
| Placebo | Placebo comparator | Three doses of 900 mg of placebo taken orally every 12 hours for 24 hours (baseline, 12 hours and 24 hours) Receives: Other: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Pressure pain detection threshold (PPDT)
Pressure pain detection threshold (PPDT) measured with an algometer one to three hours after the last dose of the study drug (24 hours after the first dose of vitamin C or placebo).
Measured: 24 hours
Secondary outcomes (3)
Pressure pain detection threshold one to three hours after the first study drug dose
Pressure pain detection threshold (PPDT) measured with an algometer one to three hours after the first dose of the study drug
Measured: 1 hours
Pressure pain tolerance threshold (PPTT) one to three hours after the last dose of the study drug
Pressure pain tolerance threshold (PPTT) measured with an algometer one to three hours after the last dose of the study drug
Measured: 24 hours
Pressure pain tolerance threshold (PPTT) one to three hours after the first dose of the study drug
Pressure pain tolerance threshold (PPTT) measured with an algometer one to three hours after the first dose of the study drug
Measured: 1 hour
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 May 2025
- Study start18 Jul 2025
- Primary completion6 Aug 2025
- Study completion19 Dec 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Pain, AcuteStudies of the same condition, open and under way.
- 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
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Double-blind randomized placebo-controlled trial
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Investigator
- Enrolment
- 38 participants (actual)
Sponsor and investigators
- Lead sponsor
- Centre Integre Universitaire de Sante et Services Sociaux du Nord de l'ile de Montreal
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Raoul Daoust, Centre Integre Universitaire de Sante et Services Sociaux du Nord de l'ile de Montreal
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06971315
- Sponsor's protocol ID
- 2025-2991
- Status last verified
- Mar 2026
- First submitted
- 6 May 2025
- Last updated
- 31 Mar 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 31 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Impact of Vitamin C on Pain Detection and Tolerance Threshold: a Double-blind Randomized Controlled Trial
- ClinicalTrials.gov ID
- NCT06971315
- Acronym / sponsor ID
- 2025-2991
- Conditions
- Pain, Acute
- Keywords
- Vitamin C, Algometer, Pain detection, Pain threshold
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 38 participants (actual)
- Lead sponsor
- Centre Integre Universitaire de Sante et Services Sociaux du Nord de l'ile de MontrealUniversity, hospital or other
- Study start
- 18 Jul 2025 (actual)
- Primary completion
- 6 Aug 2025 (actual)
- Study completion
- 19 Dec 2025 (actual)
- First posted
- 14 May 2025 (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.
Non-opioid treatments are increasingly sought after for managing acute pain. Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) (e.g., Advil, Motrin, Naproxen) combined with acetaminophen (e.g., Tylenol) have become an alternative for relieving acute pain. However, many patients cannot tolerate or have contraindications to NSAIDs and acetaminophen.
There is therefore an urgent need for studies evaluating the analgesic effects of vitamin C in the context of acute pain. Our study is conducted with healthy volunteer participants receiving either vitamin C or a placebo to assess the analgesic effect of vitamin C by comparing pain detection and tolerance thresholds.
Detailed description
Opioid-free treatments are increasingly sought for acute pain and NSAIDs have become an alternative to treat acute MSK pain and are often administered in addition to acetaminophen. However, NSAIDs can produce important adverse events and are contraindicated in many patients with comorbidities (e.g., heart disease, renal failure). Similarly, acetaminophen is contraindicated in patients with active liver disease or severe hepatic impairment.
Vitamin C has shown opioid sparing and anti-inflammatory effects mostly in postoperative contexts. Vitamin C has also demonstrated very low toxicity and rare contraindications at the dosage used in this study. Demonstrating that vitamin C increases pain detection and tolerance thresholds, thereby exhibiting an analgesic effect, could offer a valuable alternative or adjunct for patients who cannot tolerate or have contraindications to NSAIDs or acetaminophen, helping to reduce opioid use. With an aging population, the number of affected patients is expected to rise significantly.
The primary outcome is the pressure pain detection threshold (PPDT) measured with an algometer one to three hours after the last dose of the study drug (24 hours after the first dose of vitamin C or placebo).
Secondary outcomes are PPDT one to three hours after the first study drug dose, PPTT one to three hours after the initial dose and last dose of the study drug, and adverse events from the algometer or the vitamin C.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, care provider, investigator)
- Number of arms
- 2
- Model description
- Double-blind randomized placebo-controlled trial
| Arm | Type | Receives |
|---|---|---|
| Vitamin C | Experimental | Dietary Supplement: Vitamin CThree doses of 900 mg of vitamin C taken orally every 12 hours for 24 hours (baseline, 12 hours and 24 hours) |
| Placebo | Placebo comparator | Other: PlaceboThree doses of 900 mg of placebo taken orally every 12 hours for 24 hours (baseline, 12 hours and 24 hours) |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Age ≥ 18 to 65 years old;
- No acute or chronic pain;
- No pain medication;
- French or English-speaking
Key exclusion criteria (7 listed)
- Currently using vitamin C supplements;
- Pain in the last week or active cancer;
- Unavailable for follow-up;
- Allergy to milk (lactose in the placebo), or vitamin C,
- Treated with cyclosporine or warfarin (interaction with vitamin C);
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 |
|---|---|---|
| Vitamin CThree doses of 900 mg vitamin C taken orally (baseline, 12 hours and 24 hours) | Dietary supplement | Vitamin C |
| PlaceboThree doses of 900 mg placebo taken orally (baseline, 12 hours and 24 hours) | Other | Placebo |
Primary outcome
Pressure pain detection threshold (PPDT)
Time frame: 24 hours
Pressure pain detection threshold (PPDT) measured with an algometer one to three hours after the last dose of the study drug (24 hours after the first dose of vitamin C or placebo).
3 secondary outcomes
Pressure pain detection threshold one to three hours after the first study drug dose
Time frame: 1 hours
Pressure pain tolerance threshold (PPTT) one to three hours after the last dose of the study drug
Time frame: 24 hours
Pressure pain tolerance threshold (PPTT) one to three hours after the first dose of the study drug
Time frame: 1 hour
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 31 Mar 2026.
Related trials for Pain, Acute
Not yet recruiting
Human Experimental Models of Pain (HEMP)
Acute Pain
RecruitingPhase 2
REctus Sheath Trial
Acute Pain, Postoperative Pain, Acute
Not yet recruitingPhase 2
A Clinical Trial of MK-6916 in Participants With Pain After Bunion Removal Surgery (MK-6916-007)
Pain Management
Not yet recruitingPhase 2
Investigating the Analgesic Potential of (2R,6R)-HNK in Acute Pain in Healthy Volunteers
Healthy Volunteers
Not yet recruiting
Post-operative Pain and Clinical Outcome After Single-cone Obturation With a Calcium Silicate-based Versus Epoxy Resin Sealer
Post Operative Pain, Acute, Irreversible Pulpitis (Toothache)
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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Vitamin C in people with Pain, Acute, run by Centre Integre Universitaire de Sante et Services Sociaux du Nord de l'ile de Montreal at 1 site in Canada.
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 4 inclusion and 7 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: finished, as of the sponsor's last update on 31 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Pressure pain detection threshold (PPDT) (time frame: 24 hours). 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 31 Mar 2026; AzTrials last refreshed its copy on 7 Nov 2026.