TendinopathyPhase 1NCT06100822
Managing Chronic Tendon Pain by Metformin
A Phase 1 study testing Metformin in people with Tendinopathy and Chronic Pain, run by James Wang at 1 site in United States.
Trial summary
The purpose of the current exploratory clinical trial is to determine the effect of oral ingestion of metformin (OIM) in non-diabetic patients with chronic Achilles tendon pain. The trial has two aims; 1) to assess the effects of OIM treatment on tendon pain, and 2) to determine the effects of OIM capsules on tendon… Read more about this study
- Who is it for?
- Ages 18 to 50 years
- Conditions the study is for
- Tendinopathy, Chronic Pain, Achilles Tendinopathy
- What is being tested?
- Metformin
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 21 participants
- Where
- 1 siteUnited States
- Study dates
- 24 May 2024to 24 Aug 2026
- Phase
- Phase 1
- 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 50 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Willing and able to provide informed consent for participation
- Clinical diagnosis of Achilles tendinopathy
- Pain disability index score of between 20 - 70 points (0-100 scale VISA-A)
- Sonopalpation tenderness with tendon thickening and/or loss of fibrillary architecture.
- Ability to read, speak, and understand English
Who cannot join
- Any intervention (corticosteroids or other orthobiologic intervention as injection) to targeted tissue within the last 6 months.
- Previous Achilles tendon surgery.
- Known platelet abnormality or hematological disorder.
- Presence of other conditions that might affect the functional scale of the indexed limb.
- Unwillingness to be randomized.
- Body Mass Index (BMI) greater than 30.
Show all 20Show fewer
- Occult tear in the indexed tendon.
- Systemic inflammatory disease.
- Use of fluoroquinolone in the past 6 months.
- Subjects must not be pregnant or breastfeeding, or planning to become pregnant or breastfeed during the course of the trial
- Chronic kidney disease (eGFR <60)
- Diagnosis of diabetes mellitus or elevated HbA1c at screening (> 6.5)
- Unable to take an oral medication in a non crushable pill form
- Taking metformin presently or within the last 6 months
- History of allergy to metformin
- History of lactic acidosis or elevated lactate at screening (> 2.2)
- Severe Hepatic dysfunction
- Currently taking a diabetic medication such as sitagliptin, saxagliptin, linagliptin, alogliptin, sitagliptin with metformin
- Currently taking a Carbonic anhydrase inhibitor such as topiramate, zonisamide, acetazolamide, dichlorphenamide, methazolamide
- Currently taking cimetidine
Trial locations and contacts
1 site in 1 country.
United States1 site
University of Pittsburgh
Pittsburgh, Pennsylvania, 15213
About this study
Official title: Managing Chronic Tendon Pain by Repurposing Metformin
The purpose of the current exploratory clinical trial is to determine the effect of oral ingestion of metformin (OIM) in non-diabetic patients with chronic Achilles tendon pain. The trial has two aims; 1) to assess the effects of OIM treatment on tendon pain, and 2) to determine the effects of OIM capsules on tendon healing and repair. Twenty participants will be treated with metformin capsules for 16 weeks combined with a home exercise program. A comparison group of 20 participants will be treated with placebo tablets along with home exercise program.
Read the detailed description
This is a blinded and randomized controlled trial that focuses on the treatment effects of metformin (Met) on chronic tendon pain, healing, and repair in midportion Achilles tendinopathy. We will include a total 40 patients randomly divided into two equal groups:
Group 1: Home Exercise Program + Placebo as a control group
Group 2: Home Exercise Program + Oral Ingestion of Metformin
Patients in group 1 will receive placebo capsules,1 capsule (500 mg) daily for week one, 2 capsules (1,000 mg) daily for week two, 3 capsules daily for week 3 (1,500 mg), and 4 capsules daily (2,000 mg) for weeks 4-16. Patients in group 2 will receive metformin capsules,1 capsule (500 mg) daily for week one, 2 capsules (1,000 mg) daily for week two, 3 capsules daily for week 3 (1,500 mg), and 4 capsules daily (2,000 mg) for weeks 4-16. All patients will participate in a home exercise program through MedBridge, a HIPAA-compliant participant portal currently used by physical therapists at University of Pittsburgh Medical Center. There are 3 visits for this study. Visits include a Screening/Baseline visit, week 4 and week 16 visit. During each visit, participants will answer questions, complete functional testing, and undergo an ultrasound of the Achilles Tendon.
- Conditions
- Tendinopathy, Chronic Pain, Achilles Tendinopathy
- Being tested
- Metformin, Placebo
- Keywords
- Achilles Tendon, Metformin, Achilles Tendinopathy, Chronic Pain
- Medical subject headings
- Tendinopathy, Chronic Pain
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
MetforminDrug
Also called Glucophage, Glucophage XR, Metformin Extended Release, Metformin ER
500 mg capsules of Metformin Extended Release
PlaceboDrug
500 mg capsules of placebo pills
| Study group | Role | What they receive |
|---|---|---|
| Placebo Group, Placebo Capsules | Placebo comparator | Placebo Group (n=20) Week 1: One placebo capsule (500 mg) daily Week 2: Two placebo capsules (1,000 mg) daily Week 3: Three placebo capsules (1,500 mg) daily Week 4-16: Four placebo capsules (2,000 mg) daily Receives: Drug: Placebo |
| Treatment Group, Metformin Capsules | Experimental | Treatment Group (n=20) Week 1: One metformin ER capsule (500 mg) daily Week 2: Two metformin (ER) capsules (1,000 mg) daily Week 3: Three metformin (ER) capsules (1,500 mg) daily Week 4-16: Four metformin (ER) capsules (2,000 mg) daily Receives: Drug: Metformin |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Victorian Institute of Sport Assessment - Achilles (VISA-A) Score
The VISA-A is a self-administered questionnaire that asks about Achilles tendon pain, function, and activity. Scores range from 0 to 100 with a low score indicating more severe pain.
Measured: baseline, 4 weeks, 16 weeks
Secondary outcomes (11)
Change in VAS score
The VAS is a self-administered questionnaire that asks about pain. Scores range from 0 to 10 with a high score indicating more severe pain.
Measured: baseline, 4 weeks, 16 weeks
Change in tendon thickness
Images of the Achilles tendon in long axis will be acquired using B-mode ultrasound imaging. Maximum Achilles tendon thickness (mm) will be measured by a blinded investigator.
Measured: baseline, 4 weeks, 16 weeks
Change in tendon cross-sectional area
Images of the Achilles tendon in short axis will be acquired using B-mode ultrasound imaging. Maximum Achilles tendon cross-sectional area (mm^2) will be measured by a blinded investigator.
Measured: baseline, 4 weeks, 16 weeks
Change in tendon neovascularization
Achilles tendon neovascularization will be evaluated using the 5-point modified Ohberg scale:
0 - no vessels visible
- one vessel, mostly anterior to the tendon
- one or two vessels throughout the tendon
- three vessels throughout the tendon
- more than three vessels throughout the tendon
Measured: baseline, 4 weeks, 16 weeks
Change in tendon hypoechogenicity
Hypoechogenicity is indicative of disruption of the normal fibrillar structure of the Achilles tendon. Achilles tendon hypoechogenicity will be evaluated using a semi-quantitative 3-point scale:
0 - no hypoechogenicity
- - Heterogeneous echotexture with diffuse hypoechogenicity between fibrillar echoes and/or foci of discontinuity in collagen fibrillar echoes
- - Heterogeneous echotexture with discrete hypoechoic area/s of >1mm and/or presence of intrasubstance tears
Measured: baseline, 4 weeks, 16 weeks
Change in maximum number of heel raises
The subject will stand barefoot on a 10° incline board and perform heel raises at a rate of 30 Hz (2 seconds per repetition, pace provided by audible metronome), while keeping their knee straight. Subjects will be allowed to have 2 fingertips per hand at shoulder height against the wall for balance. Participants will stop when they are unable to perform any additional repetitions, or if they fail to maintain proper form. Number of repetitions will be recorded.
Measured: baseline, 4 weeks, 16 weeks
Change in heel raise height
The subject will stand barefoot on a 10° incline board and perform heel raises at a rate of 30 Hz (2 seconds per repetition, pace provided by audible metronome), while keeping their knee straight. Subjects will be allowed to have 2 fingertips per hand at shoulder height against the wall for balance. Participants will stop when they are unable to perform any additional repetitions, or if they fail to maintain proper form. Maximum height of heel rise achieved during repetitions will be measured using the Calf Raise App.
Measured: baseline, 4 weeks, 16 weeks
Change in heel raise work
The subject will stand barefoot on a 10° incline board and perform heel raises at a rate of 30 Hz (2 seconds per repetition, pace provided by audible metronome), while keeping their knee straight. Subjects will be allowed to have 2 fingertips per hand at shoulder height against the wall for balance. Participants will stop when they are unable to perform any additional repetitions, or if they fail to maintain proper form. Total work (body weight x total distance) will be measured using the Calf Raise App.
Measured: baseline, 4 weeks, 16 weeks
Change in counter movement jump height
Subjects will stand on a single leg with their hands behind their back, bend their knee as much as desired, and jump as high as possible from flat ground. Three trials will be performed. Jump height will be determined using the My Jump2 App and the highest jump height will be utilized in further analysis.
Measured: baseline, 4 weeks, 16 weeks
Change in drop counter movement jump height
Subjects will stand on a single leg on top of an 8" plyometric box, with their hands behind their back. They will be asked to "fall" down to the floor and then immediately jump as high as possible from flat ground. Three trials will be performed. Jump height will be analyzed using the My Jump2 App and the highest jump height will be utilized in further analysis.
Measured: baseline, 4 weeks, 16 weeks
Change in VAS score during hopping
Subjects will be asked to complete two 2 trials of 25 single leg hops at a natural cadence similar to jumping rope (~2 jumps/second). Subjects will be asked to rate their pain during the exercise using VAS (0-10).
Measured: baseline, 4 weeks, 16 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Oct 2023
- Study start24 May 2024
- Primary completion24 Aug 2026
- Study completion24 Aug 2026
Why it stopped: The study funding has ended.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for TendinopathyStudies 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 1
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 21 participants (actual)
Sponsor and investigators
- Lead sponsor
- James Wang
- Sponsor type
- University, hospital or other
- Collaborators
- United States Department of Defense
- Responsible party
- Sponsor-investigator, James Wang, University of Pittsburgh
- Investigators
- James H Wang, PhD, Principal investigator, University of Pittsburgh
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06100822
- Sponsor's protocol ID
- STUDY23040151
- Other IDs
- HT9425-23-1-0712
- Status last verified
- Aug 2026
- First submitted
- 9 Oct 2023
- Last updated
- 27 Aug 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: Data obtained through this study may be provided to qualified researchers. Data or samples shared will be coded, with no PHI included. Approval of the request and execution of all applicable agreements (i.e. a material transfer agreement) are prerequisites to the sharing of data with the requesting party.
Study at a glance
From the registry record, last updated by the sponsor on 27 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Managing Chronic Tendon Pain by Repurposing Metformin
- ClinicalTrials.gov ID
- NCT06100822
- Acronym / sponsor ID
- STUDY23040151
- Conditions
- Tendinopathy, Chronic Pain, Achilles Tendinopathy
- Keywords
- Achilles Tendon, Metformin, Achilles Tendinopathy, Chronic Pain
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: The study funding has ended.
- Enrolment
- 21 participants (actual)
- Lead sponsor
- James WangUniversity, hospital or other
- Collaborators
- United States Department of Defense
- Study start
- 24 May 2024 (actual)
- Primary completion
- 24 Aug 2026 (actual)
- Study completion
- 24 Aug 2026 (actual)
- First posted
- 25 Oct 2023 (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.
The purpose of the current exploratory clinical trial is to determine the effect of oral ingestion of metformin (OIM) in non-diabetic patients with chronic Achilles tendon pain. The trial has two aims; 1) to assess the effects of OIM treatment on tendon pain, and 2) to determine the effects of OIM capsules on tendon healing and repair. Twenty participants will be treated with metformin capsules for 16 weeks combined with a home exercise program. A comparison group of 20 participants will be treated with placebo tablets along with home exercise program.
Detailed description
This is a blinded and randomized controlled trial that focuses on the treatment effects of metformin (Met) on chronic tendon pain, healing, and repair in midportion Achilles tendinopathy. We will include a total 40 patients randomly divided into two equal groups:
Group 1: Home Exercise Program + Placebo as a control group
Group 2: Home Exercise Program + Oral Ingestion of Metformin
Patients in group 1 will receive placebo capsules,1 capsule (500 mg) daily for week one, 2 capsules (1,000 mg) daily for week two, 3 capsules daily for week 3 (1,500 mg), and 4 capsules daily (2,000 mg) for weeks 4-16. Patients in group 2 will receive metformin capsules,1 capsule (500 mg) daily for week one, 2 capsules (1,000 mg) daily for week two, 3 capsules daily for week 3 (1,500 mg), and 4 capsules daily (2,000 mg) for weeks 4-16. All patients will participate in a home exercise program through MedBridge, a HIPAA-compliant participant portal currently used by physical therapists at University of Pittsburgh Medical Center. There are 3 visits for this study. Visits include a Screening/Baseline visit, week 4 and week 16 visit. During each visit, participants will answer questions, complete functional testing, and undergo an ultrasound of the Achilles Tendon.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Placebo Group, Placebo Capsules | Placebo comparator | Drug: PlaceboPlacebo Group (n=20) Week 1: One placebo capsule (500 mg) daily Week 2: Two placebo capsules (1,000 mg) daily Week 3: Three placebo capsules (1,500 mg) daily Week 4-16: Four placebo capsules (2,000 mg) daily |
| Treatment Group, Metformin Capsules | Experimental | Drug: MetforminTreatment Group (n=20) Week 1: One metformin ER capsule (500 mg) daily Week 2: Two metformin (ER) capsules (1,000 mg) daily Week 3: Three metformin (ER) capsules (1,500 mg) daily Week 4-16: Four metformin (ER) capsules (2,000 mg) daily |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Willing and able to provide informed consent for participation
- Clinical diagnosis of Achilles tendinopathy
- Pain disability index score of between 20 - 70 points (0-100 scale VISA-A)
- Sonopalpation tenderness with tendon thickening and/or loss of fibrillary architecture.
- Ability to read, speak, and understand English
Key exclusion criteria (20 listed)
- Any intervention (corticosteroids or other orthobiologic intervention as injection) to targeted tissue within the last 6 months.
- Previous Achilles tendon surgery.
- Known platelet abnormality or hematological disorder.
- Presence of other conditions that might affect the functional scale of the indexed limb.
- Unwillingness to be randomized.
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 |
|---|---|---|
| MetforminAlso: Glucophage, Glucophage XR, Metformin Extended Release, Metformin ER500 mg capsules of Metformin Extended Release | Drug | Treatment Group, Metformin Capsules |
| Placebo500 mg capsules of placebo pills | Drug | Placebo Group, Placebo Capsules |
Primary outcome
Change in Victorian Institute of Sport Assessment - Achilles (VISA-A) Score
Time frame: baseline, 4 weeks, 16 weeks
The VISA-A is a self-administered questionnaire that asks about Achilles tendon pain, function, and activity. Scores range from 0 to 100 with a low score indicating more severe pain.
11 secondary outcomes
Change in VAS score
Time frame: baseline, 4 weeks, 16 weeks
Change in tendon thickness
Time frame: baseline, 4 weeks, 16 weeks
Change in tendon cross-sectional area
Time frame: baseline, 4 weeks, 16 weeks
Change in tendon neovascularization
Time frame: baseline, 4 weeks, 16 weeks
Change in tendon hypoechogenicity
Time frame: baseline, 4 weeks, 16 weeks
Change in maximum number of heel raises
Time frame: baseline, 4 weeks, 16 weeks
Change in heel raise height
Time frame: baseline, 4 weeks, 16 weeks
Change in heel raise work
Time frame: baseline, 4 weeks, 16 weeks
Change in counter movement jump height
Time frame: baseline, 4 weeks, 16 weeks
Change in drop counter movement jump height
Time frame: baseline, 4 weeks, 16 weeks
Change in VAS score during hopping
Time frame: baseline, 4 weeks, 16 weeks
Results and safety
The study was stopped early (reason given: The study funding has ended.). Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Aug 2026.
- Individual participant dataSharing planned: Yes. Data obtained through this study may be provided to qualified researchers. Data or samples shared will be coded, with no PHI included. Approval of the request and execution of all applicable agreements (i.e. a material transfer agreement) are prerequisites to the sharing of data with the requesting party.
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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. This study is not recruiting at the moment.
James H Wang, PhD principal investigator
University of Pittsburgh
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Metformin in people with Tendinopathy and Chronic Pain, run by James Wang at 1 site in United States.
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 5 inclusion and 20 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: stopped early, as of the sponsor's last update on 27 Aug 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 United States. 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.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study was stopped early (reason given: The study funding has ended.). Results are not available in the source record.
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?
Change in Victorian Institute of Sport Assessment - Achilles (VISA-A) Score (time frame: baseline, 4 weeks, 16 weeks). 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 27 Aug 2026.