The four key ingredients
Short profiles of the four most recognisable names in the 1,398 mg formulation. The fifth, boswellia serrata, is covered in the science section on the homepage.
The label lists five ingredients in order of weight and stops there. Because the formulation is proprietary, no amount is published for any of them, so what follows describes each ingredient and the research behind it — not how much of it is in your capsule.
Glucosamine
Glucosamine sulfate
A building block the body already makes, found in the tissue that pads and lubricates a joint.
The most tested ingredient in this category and the most argued about. Several big independent trials saw a change in more painful knees. Others saw nothing placebo did not do.
Turmeric
Curcuma longa root
The kitchen root whose active part, curcumin, is one of the most studied plant compounds there is.
Looked at for joint comfort and for an inflammatory response that is already in the normal range. How much the body absorbs is the weak point in most of that work.
MSM
Methylsulfonylmethane
A sulfur compound found in small amounts in plants and in the body, and a regular partner to glucosamine in joint formulas.
A handful of short controlled studies on knee discomfort and on soreness after exercise. Encouraging, not settled.
Quercetin
A dietary flavonoid
The pigment in onions, apples and capers, and one of the better mapped flavonoids in nutrition research.
Antioxidant activity is the solid finding. The work on inflammatory signaling is mostly cells and animals rather than people.