CompletedNCT07809282Updated Sep 9, 2026

A Study of Mitragynine Formulations for Exercise-Induced Muscle Soreness in Healthy Adults

A Phase 2 interventional study of SpecioTea and MitraPlex in Delayed Onset Muscle Soreness (DOMS) and Exercise-Induced Muscle Soreness, sponsored by Traditional Naturals Research Inc.. Completed at 1 site in Canada. Open to participants aged 18 Years to 55 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-09.

Sponsored by Traditional Naturals Research Inc. · Phase 2, Interventional, and Treatment

From the registry’s dates

Registered 1 year 6 months after the study started (first participant enrolled Feb 2025, registered Aug 2026).

Phase: Phase 2
Study type: Interventional
Enrollment: 100
Allocation: Randomized
Ages: 18 Years to 55 Years
Sex: All

Study summary

This Phase II randomized, double-blind, placebo-controlled study will evaluate the safety, tolerability, and physical dependence potential of mitragynine-containing formulations after 28 days of use and assess their effects on exercise-induced muscle soreness in healthy adults. One hundred participants will be randomized in a 1:1:1:1 ratio to SpecioTea 20 mg, SpecioTea 40 mg, MitraPlex 20 mg, or placebo. Participants will complete an exercise challenge to induce delayed-onset muscle soreness (DOMS), undergo efficacy assessments at 24 and 48 hours post-exercise, and continue daily dosing for approximately 28 days followed by withdrawal and safety assessments.

Read the detailed description

This Phase II study is a prospective, randomized, double-blind, placebo-controlled clinical trial designed to evaluate the safety, tolerability, and potential physical dependence associated with two mitragynine-containing formulations (SpecioTea and MitraPlex), while also assessing their efficacy in reducing exercise-induced muscle soreness in healthy adults. Participants will be randomized in a 1:1:1:1 ratio to receive SpecioTea 20 mg, SpecioTea 40 mg, MitraPlex 20 mg, or placebo. The study will enroll approximately 100 healthy adults aged 18 to 55 years who are naïve to kratom use or occasional kratom users and who demonstrate delayed-onset muscle soreness (DOMS) following a screening exercise challenge. Randomization will be stratified by sex.

The study duration for each participant will be approximately 11.5 weeks and will consist of a screening period, an acute efficacy phase, a 28-day supplementation period, and post-treatment follow-up assessments. During screening, participants will complete an exercise challenge designed to induce DOMS. Forty-eight hours later, participants will complete a Visual Analogue Scale (VAS) assessment remotely to confirm the presence of muscle soreness and eligibility for enrollment. Eligible participants will return for the baseline visit at least 27 days after the screening exercise challenge.

At baseline, participants will undergo efficacy and safety assessments, including vital signs, laboratory testing, muscle soreness assessment, strength assessment, range of motion measurements, and evaluations using the Subjective Opiate Withdrawal Scale (SOWS) and Clinical Opiate Withdrawal Scale (COWS). Participants will then receive their assigned study intervention and consume the first dose in clinic. Between 45 and 90 minutes after dosing, participants will complete a standardized exercise challenge intended to induce muscle soreness. Biomarkers of muscle damage, including creatine kinase, lactate dehydrogenase, myoglobin, and creatinine, will be measured before and after exercise. Participants will return approximately 24 and 48 hours after the exercise challenge for additional assessments of muscle soreness, muscle strength, range of motion, and biomarkers of muscle damage.

Following completion of the acute exercise phase, participants will begin once-daily at-home dosing for 28 ± 2 days. Participants assigned to active treatment will receive either SpecioTea or MitraPlex capsules providing 20 mg or 40 mg of mitragynine per day, depending on randomization group. Participants assigned to placebo will receive matching placebo capsules. All participants will consume four capsules daily, and study products will be visually identical to maintain blinding.

The primary objective is to evaluate safety and tolerability after 28 days of continued use. Safety assessments include adverse event monitoring, vital signs, body weight, body mass index, hematology and clinical chemistry laboratory evaluations, and assessments of potential withdrawal symptoms using the SOWS and COWS instruments. Safety laboratory assessments include hematology parameters and clinical chemistry measures such as liver function tests, kidney function markers, electrolytes, glucose, and protein measurements.

Secondary and exploratory objectives are to evaluate the effects of the study interventions on exercise-induced muscle soreness, joint stiffness, muscle strength, and biomarkers of muscle damage. Efficacy outcomes include changes from baseline in VAS scores, knee range of motion, one-repetition maximum (1-RM) strength measures, and serum concentrations of creatine kinase, lactate dehydrogenase, myoglobin, and creatinine following exercise. Assessments will be performed at baseline and at multiple post-exercise timepoints to characterize treatment effects relative to placebo.

After completion of the 28-day dosing period, participants will return for follow-up visits to evaluate safety, collect laboratory data, assess treatment compliance, and monitor for withdrawal symptoms. Follow-up visits will occur the day after the last dose, 2 days later, and 13 days later. These visits will include SOWS and COWS assessments, review of concomitant medications, evaluation of changes in health status, and monitoring for adverse events. The study is intended to provide information regarding the safety profile of mitragynine-containing products and their potential utility in reducing post-exercise muscle soreness in healthy adults.

Conditions studied

Delayed Onset Muscle Soreness (DOMS)
Exercise-Induced Muscle Soreness

Browse trials for

Myalgia 256

Keywords

Mitragynine
Delayed Onset Muscle Soreness (DOMS)
Exercise-Induced Muscle Soreness

In context

Myalgia

256 studies on the registry are indexed under Myalgia; 46 are open to participants now.

This study's enrollment of 100 is above the median of 44 across 216 interventional studies indexed under Myalgia.

Browse Myalgia studies →

Lead sponsor

This is the only study on the registry with Traditional Naturals Research Inc. as lead sponsor.

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

Who can participate

Ages eligible: 18 Years to 55 Years
Sexes eligible: All
Accepts healthy volunteers: Yes

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

Healthy males and females who are 18 to 55 years of age (inclusive).
In good general health as deemed by the investigator and are able to consume the study product.
Have a between 18.0 to 34.9 kg/m2 (inclusive).
Naïve to kratom use or occasional kratom use (i.e., have not used kratom more than once within 28 days prior to baseline [Visit 2]).
Non-smokers (including nicotine vaping) and have not used nicotine-containing products (patches, gums, etc.) for > 3 months prior to baseline (Visit Note: Non-smoker is defined as someone who does not habitually/regularly use products containing nicotine.
Appropriate for exercise as determined by the PAR-Q at screening (Visit 1A).
Demonstrate DOMS 48 h post-exercise by having a VAS ≥ 40 mm after completion of the exercise challenge at Visit 1A.
Agree to follow the restrictions on concomitant treatments.
Agree to follow the restrictions on lifestyle (especially regarding physical activity).
Agree to use acceptable methods.
Have suitable veins for repeated venipuncture as deemed by the investigator.
Have maintained consistent dietary habits (including medication and supplement intake), exercise and lifestyle habits for the last 3 months before screening (Visit 1A) and agree to maintain them throughout the study (unless required per the restrictions).
Willing and able to agree to the requirements of this study, be willing to give voluntary consent, be able to understand and read the questionnaires, and carry out all study-related procedures.

Exclusion criteria

Exclusion Criteria:

Individuals who are lactating, planning to become pregnant during the study, or pregnancy as confirmed by a positive urine pregnancy test at screening Visit 1A or Visit 2.
Have a positive drug screen for any of the compounds listed as confirmed at screening Visit 1A or Visit 2.
Have a known sensitivity, intolerability, or allergy to any of the study products or their , or the rescue medication, NARCAN® (naloxone).
Current COVID-19 infections, or currently have the post COVID-19 condition as defined by World Health Organization (WHO) (i.e., individuals with a history of probable or confirmed SARS-CoV-2 infection, usually 3 months from the onset of COVID-19 with symptoms that last for at least 2 months and cannot be explained by an alternative diagnosis).
Have exercised regularly (generally > 150 cumulative minutes per week) for 6 months prior to screening (Visit 1A) and/or Visit 2.
Have engaged in regular lower extremity fitness activities (e.g., running, cycling, soccer or hockey) for more than two times per week for ≥ 2 consecutive weeks in the past 6 months prior to screening (Visit 1A) and/or Visit 2.
Had lower body surgery (e.g., hips, knees, ankles, etc.) within 6 months prior to screening (Visit 1A) and/or planned lower body surgery during the study.
History of any lower body injury [e.g., partial anterior cruciate ligament (ACL) tear, broken or fractured bone, major sprain] within 6 months prior to screening (Visit 1A) and/or during the study.
Have Type I/Type II diabetes or thyroid disease.
Have uncontrolled or controlled high blood pressure (≥140 systolic or ≥90 diastolic mmHg) at screening.
Have medical condition(s) known to interfere with absorption, distribution, metabolism, or excretion of the study product (e.g., Crohn's disease, short bowel, acute or chronic pancreatitis, or pancreatic insufficiency).
Have a history of heart/cardiovascular disease, immune disorders and/or (i.e., /AIDS).
Have active asthma or have experienced an asthma attack in the last 5 years.
Have a history of neurological disorders such as epilepsy.
Have hepatic or renal dysfunction as evidenced by and/or AST being ≥ 2 times the (ULN), serum creatinine or urea value ≥ 1.5 times the ULN, or other abnormal clinical laboratory value per investigator discretion.
Have a history of cancer (except localized skin cancer without or in situ cervical cancer), unless recovery occurred more than 5 years before the screening visit.
Are receiving treatments for or have been hospitalized in the last 12 months for psychiatric disorders (e.g., depression, bipolar disorder, schizophrenia, etc.).
Have known genetic polymorphisms of CYP450, , CYP2D6, and/or CYP1A2 enzymes.
Reports a clinically significant illness during the 28 days before the first dose of study product.
Major surgery in 3 months prior to screening or planned major surgery during the study.
Reports a significant blood loss or blood donation totaling between 101 mL to 449 mL of blood within 30 days prior to Visit 2 or a blood donation of more than 450 mL within 56 days prior to Visit 2.
Reports donating plasma (e.g., plasmapheresis) within 15 days prior to Visit 2.
Have a history of alcohol or substance abuse in the 12 months prior to Visit 1A (including having been hospitalized for such in an in-patient or out-patient intervention program) or use that to the opinion of the investigator may be of a concern for the study.
Currently consumes more than 2 standard alcoholic beverages per day on average for 4 weeks prior to Visit 1A. A standard alcoholic beverage is defined as 12 ounces of beer, 5 ounces of wine or 1.5 ounces of liquor.
Evidence of addictive tendency as indicated by an LDQ score ≥ 21 at Visit 1A.
Current enrolment or past participation in another study with any product(s) with at least one active ingredient within 28 days before Visit 1A or longer, if the previous test product is deemed by the investigator to have lasting effects that might influence the eligibility criteria or outcomes of current study.
Living in the same household as another currently/previously enrolled participant in the present study.
Any other medical condition/situation or use of medications/supplements/therapies that, in the opinion of the investigator, may adversely affect the participant's ability to participate in the study or its measures or pose a significant risk to the participant.

Terms in these criteria, in plain language(10)

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.

BMI (body mass index)

Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.

What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

Excipients

The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.

Immunosuppression

A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.

Read whether the line is about a condition or about medicines, and which medicines and doses it means.

HIV

The human immunodeficiency virus, which weakens the immune system.

Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.

ALT and AST (liver enzymes)

Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.

Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.

ULN (upper limit of normal)

The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.

“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.

Clinically significant

Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.

Metastases

Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.

CYP3A (CYP3A4) inhibitors and inducers

CYP3A is a group of enzymes, mainly CYP3A4, in the liver and gut that break down many medicines. Some medicines, supplements and foods (grapefruit, St John’s wort) slow them down or speed them up, which changes how much of a study drug stays in the body.

Studies list them so they can be avoided or switched; bring a list of everything you take, including supplements.

Study design

Phase: Phase 2
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel assignment
Masking: Quadruple (Participant, Care provider, Investigator, Outcomes assessor)
Enrollment: 100 participants (actual)

Study arms

Experimental
SpecioTea 20 mg
Participants receive 4 capsules daily containing a total of 20 mg mitragynine (2 active capsules plus 2 placebo capsules).
Dietary Supplement: SpecioTea
Experimental
SpecioTea 40 mg
Participants receive 4 active capsules daily containing a total of 40 mg mitragynine.
Dietary Supplement: SpecioTea
Experimental
MitraPlex 20 mg
Participants receive 4 active capsules daily containing a total of 20 mg mitragynine.
Dietary Supplement: MitraPlex
Placebo comparator
Placebo
Participants receive 4 placebo capsules daily.
Other: Placebo

Interventions

Dietary supplementSpecioTea
SpecioTea is a dried aqueous kratom leaf extract administered orally in capsule form. Participants receive 4 capsules once daily. The study evaluates two dosage levels: 20 mg mitragynine daily (2 active capsules plus 2 placebo capsules) and 40 mg mitragynine daily (4 active capsules).
Dietary supplementMitraPlex
MitraPlex is a dried ethanolic/water kratom leaf extract administered orally in capsule form. Participants receive 4 active capsules once daily providing a total daily dose of 20 mg mitragynine.
OtherPlacebo
Matching placebo capsules administered orally. Participants receive 4 placebo capsules once daily. Placebo capsules are visually indistinguishable from active study product capsules to maintain blinding.

What researchers measure

Primary outcomes

Safety and Tolerability After 28 Days of Use (Vitals)
Heart Rate (bpm)
Time frame: Baseline through Visit 7 (approximately 45 days) with primary safety assessment after 28 ± 2 days of dosing.
Safety and Tolerability After 28 Days of Use (Vitals)
Blood Pressure (mmHg)
Time frame: Baseline through Visit 7 (approximately 45 days) with primary safety assessment after 28 ± 2 days of dosing.
To assess the effect of each TP intervention on changes in creatinine compared to each other and to a placebo
Change in concentration of creatinine
Time frame: Change from baseline to 1 hour, 24 hours, and 48 hours post-exercise
To assess the effect of each TP intervention on changes in myoglobin compared to each other and to a placebo
Change in concentration of myoglobin
Time frame: Change from baseline to 1 hour, 24 hours, and 48 hours post-exercise
To assess the effect of each TP intervention on changes in lactose dehydrogenase (LDH) compared to each other and to a placebo
Change in concentration of LDH
Time frame: Change from baseline to 1 hour, 24 hours, and 48 hours post-exercise
To assess the effect of each TP intervention on changes in CK compared to each other and to a placebo
Change in concentration of creatine kinase (CK)
Time frame: Change from baseline to 1 hour, 24 hours, and 48 hours post-exercise
To assess the effect of each TP intervention on muscle strength after intense exercise compared to each other and to a placebo
Change in the maximum weight moved
Time frame: Change from baseline to 24 hours and 48 hours post-exercise
To assess the effect of each TP intervention on reducing joint stiffness after intense exercise compared to each other and to a placebo
Change in the magnitude of joint range of motion (degrees)
Time frame: Change from baseline to 24 hours and 48 hours post-exercise
To assess the efficacy of each TP intervention on reducing exercise-induced muscle soreness at 24 h and 48 h post-exercise compared to each other and to a placebo
Change in Visual Analog Scale score. Participants will draw a vertical line on 100 mm scale that represents the current intensity of their pain where left end of the scale is representative of "no soreness at all" and the right end of the scale is representative of "extreme soreness". The intensity of pain will be considered to be the distance (in mm) of the participant's mark from the left-hand side of the scale.
Time frame: Change from baseline to 24 hours and to 48 hours post-exercise
Safety and Tolerability After 28 Days of Use (Anthropometrics)
Assessment of Body weight (kg)
Time frame: Baseline through Visit 7 (approximately 45 days) with primary safety assessment after 28 ± 2 days of dosing.
Safety and Tolerability After 28 Days of Use (Anthropometrics)
Assessment of BMI (kg/m2)
Time frame: Baseline through Visit 7 (approximately 45 days) with primary safety assessment after 28 ± 2 days of dosing.
Safety and Tolerability After 28 Days of Use (Laboratory Blood Tests)
Blood samples will be collected to assess hematology parameters (hemoglobin, hematocrit, red blood cell \[RBC\], red blood cell distribution width \[RDW\], RBC indices \[mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), MCH concentration (MCHC)\], white blood cells \[WBC\] with differential \[abs\], platelet count, mean platelet volume \[MPV\]).
Time frame: Baseline through Visit 7 (approximately 45 days) with primary safety assessment after 28 ± 2 days of dosing.
Safety and Tolerability After 28 Days of Use (Laboratory Blood Tests)
Change from baseline in clinical chemistry laboratory parameters. Blood samples will be collected to assess clinical chemistry parameters including urea, creatinine, total bilirubin, alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), random serum glucose, albumin, globulin, total protein, sodium, potassium, estimated glomerular filtration rate (eGFR), and chloride. Each laboratory parameter will be evaluated and reported separately according to its standard unit of measurement, with change from baseline summarized for each parameter.
Time frame: Baseline through Visit 7 (approximately 45 days) with primary safety assessment after 28 ± 2 days of dosing.
Safety and Tolerability After 28 Days of Use (Adverse Events)
Reports of AEs
Time frame: Baseline through Visit 7 (approximately 45 days) with primary safety assessment after 28 ± 2 days of dosing.
Safety and Tolerability After 28 Days of Use (SOWS)
Changes in Subjective Opiate Withdrawal Scale (SOWS) scores for grading opioid withdrawal symptoms. A SOWS total score of 1-10 is considered mild, 11-20 moderate and 21-30 severe. On both scales, greater scores correspond to increased perception of any of the symptoms.
Time frame: Baseline through Visit 7 (approximately 45 days) with primary safety assessment after 28 ± 2 days of dosing.
Safety and Tolerability After 28 Days of Use (COWS)
Changes in Clinical Opiate Withdrawal Scale (COWS) scores which is the summed score used to determine the stage or severity of opiate withdrawal and assess the level of physical dependence on opioids (score of below 5 = no withdrawal; 5-12 = mild; 13-24 = moderate; 25-36 = moderately severe; more than 36 = severe withdrawal).
Time frame: Baseline through Visit 7 (approximately 45 days) with primary safety assessment after 28 ± 2 days of dosing.

Study locations

1 site

Apex Trials
Guelph, Ontario - on N1G 0B4, Canada

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

Timeline

Tracking since Sep 25, 2026

ElapsedEstimatedEstimated, not yet reached

Ran from Feb 2025 to primary completion in Oct 2025, 8 months.

How these figures are worked out, and which studies are left out of them.

Registered: Aug 28, 2026
First posted: Sep 9, 2026
StartActual: Feb 5, 2025
Primary completionActual: Oct 22, 2025
CompletionActual: Oct 22, 2025
Last update: Sep 9, 2026

What these dates mean

Start.: When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.: When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.: When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.: Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.

No changes since tracking began. The registry record was last updated on Sep 9, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗

Registry details

Key details

Study ID: NCT07809282
Lead sponsor: Traditional Naturals Research Inc.
Collaborators: Nutrasource Pharmaceutical and Nutraceutical Services, Inc.
Responsible party: Sponsor
First posted: Sep 9, 2026
Start date: Feb 5, 2025
Primary completion: Oct 22, 2025
Completion: Oct 22, 2025
Last update: Sep 9, 2026

Oversight

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

View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is completed, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.

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