NAtive Collagen Type II In Healthy VoluntEers With Joint Discomfort

This study will include 100 healthy volunteers in which will be evaluated if the collagen supplement is able to obtain differences versus placebo in pain and function. It will be a randomized, double-blind, placebo-controlled study with proportion 1:1 between treatments

• Native type II collagen (Dietary supplement): 1 capsule/day
• Placebo (Dietary supplement): 1 capsule/day

Primary outcomes

• Change in joint discomfort onset [Change in joint discomfort onset at 6 months]: Determine differences from baseline on reaching a joint pain of 5/1 while going up and down stairs (max 10 min).

Secondary outcomes

• Joint discomfort [Day 0 to day 60, 90, 120, 180]: Visual Analog Scale (VAS, 0-10cm) pain at rest and during activity. A higher VAS means higher pain levels
• Joint function [Day 0 to day 60, 90, 120, 180]: Knee injury and Osteoarthritis Outcome Score (KOOS) test
• Time to Joint discomfort [Day 0 to day 60, 90, 120, 180]: Time to joint discomfort and to recover from pain in 3 different exercises
• 6 minute walking timed test (6MWT) [Day 0 and 180]: Distance a person is capable of walking on a flat, hard surface in 6 minutes
• Rescue medication consumption [Day 0 to 180, anytime]: Rescue medication: Paracetamol 500mg. max 2 pills/day
• Cartilage turnover biomarkers [Day 0 and 180]: Cartilage turnover biomarkers will be measured in blood and urine (CTX-II, C2C, CPII)

Other outcomes

• Daily activity levels [Day 0 to 180, anytime]: A fitness tracker will monitor the steps taken daily
• Muscle quality [Day 0 and 180]: Muscle quality will be evaluated by an ultrasound index
• Safety assessment [Day 0 to 180, anytime]: Adverse events
• Safety assessment [Day 0 to day 60, 90, 120, 180]: Medical exams (weight in kilograms, height in meters, BMI in kg/m\^2)
• Safety assessment [Day 0 to day 60, 90, 120, 180]: Vital signs (heart rate in bpm and blood pressure mmHg)
• Safety assessment [Day 0 and 180]: Laboratory analysis (total blood count, glucose, AST, ALT, Cholesterol, Creatinine, BUN, triglycerides, alkaline phosphatase)

Sex: All, ages: 30 Years to 65 Years, accepts healthy volunteers

Inclusion Criteria:

* Males and non-pregnant females 30-65 years old with a Body Mass Index (BMI) of approximately 18 to 30 kg/m2. (see Section 4.0)
* Unilateral or bilateral knee discomfort for greater than 3 months.
* VAS score during knee movement between 30-50 mm after 7-day withdrawal of excluded medications.
* Reach joint discomfort of 5/10 on a 11-point Likert scale ( score 0 to 10) within 10 minutes of going up and down stairs.
* Clinical laboratory results that are within normal range or considered not clinically significant by the Principal Investigator.
* Be willing to participate in all scheduled visits, tests, and other trial procedures according to the clinical protocol. To do so and be able of using the fitness tracker, a phone or tablet compatible with the Fitbit app is required. (Apple iOS 12.2 or higher, Android OS 7.0 or higher.)
* Be willing to refrain from taking ibuprofen, aspirin or other Non-steroidal anti-inflammatory drugs (NSAIDs), or any other pain reliever (OTC (Over the Counter) or prescription) during the entire study other than acetaminophen (paracetamol) as rescue medication.
* Provide a signed and dated informed consent indicating that the subject has been informed of all pertinent aspects and possible risks associated with participation in the study.
* Be willing to refrain from taking dietary supplements during the entire study that have any underlying joint benefit (collagen, glucosamine, chondroitin, MSM, Hyaluronic Acid, Turmeric, Natural Eggshell Membrane, Omega-3 fatty acids, PEA, Boswellia,…)

Exclusion Criteria:

* History of hypersensitivity to the rescue medication or any of the products used in the study.
* Requirement of drugs to control joint discomfort.
* Regular drug intake to control any kind of pain.
* History of hypersensitivity to eggs, chicken, or fowl.
* History of Knee OA (OsteoArthritis), inflammatory arthropathy, RA (Rheumatoid Arthritis), OA (VAS score greater than 50), or Systemic Lupus Erythematosus.
* Hyperuricemia (>440 μmol/L), history of gout, or both.
* Exercising (intentionally) for more than 10 hours a week
* High intensity exercise for more than 5 hours a week
* Anticipation of surgery within the next 6 months.
* Recent injury in the target knee (past 4 months).
* History of congestive heart failure.
* Anticipated problems with product consumption.
* Evidence or history of clinically significant haematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, neurologic diseases, or malignancies within the last 5 years.
* High alcohol intake (>2 standard drinks per day) or use of recreational drugs (e.g., cocaine, methamphetamine, marijuana, etc.).
* Females who are pregnant or lactating or planning to become pregnant.
* History of any mental illness that might impair the ability of subjects to provide a written informed consent.
* Use of oral corticosteroid, indomethacin, SYSADOAs (symptomatic slow action drug osteoarthritis) within 3 months of Visit 1; topical treatment with corticosteroids within 1 week of visit 1, and consumption of Omega 3 fatty acids or any other joint health dietary supplements within 2 weeks preceding the treatment period.
* Consumed, ibuprofen, aspirin or other NSAIDS, or any other pain reliever (OTC or prescription), or any natural health product, (excluding vitamins) within 7 days of first visit.
* Consumed acetaminophen (paracetamol) within 48 hours of randomization visit.
* Participation in any clinical trials within 30 days prior to first visit.
* Individuals following an energy restricted diet for weight loss

• Results publication: Moller I, Martinez K, Terradillos-Guillen A, Costa-Larrion E, Martinez-Puig D, Velasco-Alvarez J. Efficacy and tolerability of native (undenatured) type II collagen supplementation for joint health in healthy volunteers: a randomized double-blind placebo-controlled study. Nutr J. 2026 Mar 6;25(1):46. doi: 10.1186/s12937-026-01302-0. PMID 41787523