Every time you see "70.3% joint improvement," that number came from somewhere specific: the WOMAC index. Understanding what WOMAC measures is the difference between trusting a number and being sold one. It's the most-used joint-assessment tool in clinical research, and it's simpler than it sounds. For the broader context, see joint discomfort after 40.
What WOMAC stands for
WOMAC is the Western Ontario and McMaster Universities Osteoarthritis Index — a standardized, validated questionnaire developed to measure joint symptoms consistently across studies. "Validated" is the key word: it's been tested to make sure it actually captures what it claims to, which is why researchers trust it and why a WOMAC-based result carries more weight than "participants felt better."
The three things it measures
WOMAC scores three domains:
- Pain — discomfort during activities like walking, stairs, and rest.
- Stiffness — including that classic morning stiffness after rest.
- Physical function — how easily everyday movements get done: rising from a chair, getting in a car, bending.
A participant rates each item, and the responses combine into scores. Because it's the same instrument every time, a "31.79% WOMAC improvement" in one study is directly comparable to another study using WOMAC.
Why "improvement %" is what you want to see
When a study reports a percentage improvement on WOMAC, it means the total symptom score dropped by that proportion — a lower WOMAC score means less discomfort, less stiffness, and better function. That's far more meaningful than a vague satisfaction figure, because it's a validated, multi-domain measure.
What the research says
Here's WOMAC in action across the Q-Actin® research: a 70.3% WOMAC improvement over 180 days versus 33.7% for glucosamine-chondroitin (Nash et al., 2018, PMC6207263), and a 31.79% WOMAC improvement from baseline over 60 days in a placebo-controlled study (Hausenblas et al., 2025). Because both use WOMAC, you can line them up directly. Individual results may vary.
How to use this when reading claims
Next time a joint product cites an improvement percentage, ask: improvement on what scale? If the answer is WOMAC (or another validated index) in a real, citable study, the number means something. If it's an unnamed internal "satisfaction" survey, it doesn't. This one question separates evidence from marketing — the same principle we cover in what "clinically studied" actually means.
It's also why we cite the specific WOMAC results and link the studies directly — so you can check the scale, not just the number. To see how these WOMAC results compare to the old standard, read Q-Actin® vs glucosamine.
Frequently Asked Questions
What does WOMAC measure?
Three domains of joint health: pain, stiffness, and physical function. It's a standardized, validated questionnaire used across joint research.
What does a "70.3% WOMAC improvement" mean?
The participants' total WOMAC symptom score dropped by 70.3% — meaning less pain, less stiffness, and better function on a validated scale. Individual results may vary.
Why is WOMAC better than a satisfaction survey?
Because it's validated and standardized. It measures the same defined domains every time, so results are comparable across studies — unlike a vague "did you feel better?" survey.
Written by Dr. Mohammed Hawa, DHA, Founder of VyVa.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. Individual results may vary. Consult your healthcare provider before beginning any supplement, particularly if you are pregnant, breastfeeding, under 18, or taking prescription medication.
