Effect of Agar/Collagen-based Compounds on Osteoarticular Pain: Randomized Triple-blind Clinical Trial
AGARTROSIS
Evaluation of the Effect of Agar and/or Collagen Based Compounds on Osteoarticular Pain. A Randomized, Parallel, Placebo Controlled, Triple Blind Clinical Trial (AGARTROSIS)
1 other identifier
interventional
80
1 country
1
Brief Summary
Joints-comprising bone, cartilage, ligaments, and synovial fluid-enable stable daily movement but may deteriorate with age, excess body weight, overuse, injury, or disease. Such degeneration, common from age 40 onward, underlies joint disorders like osteoarthritis, particularly in the knees, hips, hands, and spine, and is a major cause of chronic pain and disability. While antiinflammatory analgesics remain the standard approach to symptom control, they neither cure disease nor regenerate cartilage and can produce significant long-term adverse effects (gastrointestinal, hepatic, renal, and cardiovascular). These limitations motivate interest in natural or complementary strategies with safer profiles. Within this context, marine algae, especially agar derived from red seaweed, have attracted attention for potential intestinal, metabolic, and joint benefits, aided by their fiber content. Another promising option is undenatured type II collagen (UC-II), the principal structural component of articular cartilage, whose endogenous production declines with age; clinical studies indicate that a daily intake of 40 mg UC-II can improve mobility, reduce pain, and enhance quality of life in individuals with osteoarthritis or exercise-related joint discomfort. Based on these considerations, an agar-agar supplement has been developed to relieve knee joint symptoms.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P50-P75 for not_applicable
Started Nov 2025
1 active site
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
Study Start
First participant enrolled
November 10, 2025
CompletedFirst Submitted
Initial submission to the registry
November 20, 2025
CompletedFirst Posted
Study publicly available on registry
January 6, 2026
CompletedPrimary Completion
Last participant's last visit for primary outcome
February 1, 2027
ExpectedStudy Completion
Last participant's last visit for all outcomes
February 1, 2027
January 6, 2026
December 1, 2025
1.2 years
November 20, 2025
December 19, 2025
Conditions
Keywords
Outcome Measures
Primary Outcomes (1)
Change in perception of knee joint pain.
This will be determined using the pain subscale of the Western Ontario and McMaster Universities Osteoarthritis Index questionnaire. The questionnaire assesses clinically meaningful changes in symptoms and physical disability in individuals with osteoarthritis or those experiencing joint discomfort. It evaluates the perceived intensity of knee pain using the Likert scale (0: no pain; 1: mild pain; 2: moderate pain; 3: severe pain; 4: extreme pain).
Before (baseline), during (6 weeks) and after treatment period (12 weeks).
Secondary Outcomes (42)
Body weight.
at week 1.
Height.
At week 1.
Body mass index (BMI) (kg/m^2).
At week1.
Age.
At week 1.
Changes in systolic and diastolic blood pressure and resting heart rate.
Before (baseline) and after treatment period (12 weeks).
- +37 more secondary outcomes
Study Arms (4)
Agar-Agar (A-A)
EXPERIMENTALParticipants assigned to this group will receive agar-agar (A-A) supplementation and will take it for 12 weeks.
Agar-Agar + undenatured collagen type II (A+UC-II)
EXPERIMENTALParticipants assigned to this group will receive agar-agar and undenatured collagen type II (A+UC-II) supplementation and will take it for 12 weeks.
undenatured collagen type II (UC-II)
ACTIVE COMPARATORParticipants assigned to this group will receive undenatured collagen type II (UC-II) supplementation and will take it for 12 weeks.
Placebo
PLACEBO COMPARATORParticipants assigned to this group will receive the placebo and will take it for 12 weeks.
Interventions
2.4 g of agar-agar (Rhodophyceae group) presented in capsule form will be given.
2.4 g of agar- agar + 40 mg of undenatured collagen type II, presented in capsule form will be given.
40 mg of undenatured collagen type II + 2.4 g of maltodextrin will be given in capsule form
Eligibility Criteria
You may qualify if:
- Men and women between 40 and 70 years of age.
- Submit a score of 6 to 10 out of 20 on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) knee pain questionnaire.
- Sign the informed consent form.
- Know how to read, write, and speak Spanish and/or Catalan.
You may not qualify if:
- Present body mass index (BMI) values \<18.5 kg/m\^2 or ≥30 kg/m\^2.
- Present intolerances or allergies related to Agar-Agar, or any of the components of the products being evaluated, such as collagen or maltodextrin.
- Take or have taken medications that may affect the study results. This is especially true for those who have been treated with oral or intra-articular corticosteroids within the 4 and 12 weeks prior to screening, respectively, or medications for osteoarthritis at the time of screening.
- Patients who depend on prescription medications for pain control.
- Take multivitamin or mineral supplements, collagen derivatives, or supplements containing bioactive compounds that may exert an anti-inflammatory effect, such as turmeric, ginger, omega-3, or polyphenol supplements.
- (Individuals who consume multivitamin, mineral, or collagen-derived supplements or supplements will be eligible to participate in the study, provided they are willing to discontinue their intake for at least two weeks prior to the start of the study and throughout the entire study period).
- Be an active smoker or have been one for less than 6 months.
- Alcohol consumption:
- Men: Consume 4 or more Standard Drink Units (SDU) daily or SDUs weekly.
- Women: Consume 2 or more Standard Drink Units (SDU)\* daily or SDUs weekly.
- Have a diagnosis of osteoarthritis, active rheumatoid arthritis, and any inflammatory arthritic condition such as secondary inflammatory arthritis, gout, pseudogout, knee infection, marked angular deformities, or significant injury to the target joint within the 6 months prior to the start of the trial; arthroplasty and joint surgery of the target knee within the 2 years prior to the start of the study.
- Have any gastrointestinal disease that affects the absorption of the compound and/or the study results, such as celiac disease, Crohn's disease, active cancer of any organ of the digestive or renal system, or hepatitis.
- Be ineligible to participate in the study, according to the pre-screening evaluator's criteria.
- Have lost 3 kg or more in the last 3 months.
- Be pregnant or intend to become pregnant.
- +2 more criteria
Contact the study team to confirm eligibility.
Sponsors & Collaborators
- Fundació Eurecatlead
- HISPANAGAR SAcollaborator
Study Sites (1)
Eurecat, Technological Center of Catalonia, Nutrition and Health Unit
Reus, Tarragona, 43204, Spain
Related Links
MeSH Terms
Conditions
Interventions
Condition Hierarchy (Ancestors)
Intervention Hierarchy (Ancestors)
Study Officials
- PRINCIPAL INVESTIGATOR
Antoni Caimari Palou, PhD
UTNS (Eurecat, Reus)
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- not applicable
- Allocation
- RANDOMIZED
- Masking
- QUADRUPLE
- Who Masked
- PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
- Purpose
- TREATMENT
- Intervention Model
- PARALLEL
- Sponsor Type
- OTHER
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
November 20, 2025
First Posted
January 6, 2026
Study Start
November 10, 2025
Primary Completion (Estimated)
February 1, 2027
Study Completion (Estimated)
February 1, 2027
Last Updated
January 6, 2026
Record last verified: 2025-12
Data Sharing
- IPD Sharing
- Will not share