Glucosamine and chondroitin are substances naturally present in cartilage, collagen, bones and synovial fluid in the joints. They are rarely found in the foods we eat, as we don’t often eat cartilage or bones! In supplements, glucosamine is often sourced... Read more
Glucosamine and chondroitin are substances naturally present in cartilage, collagen, bones and synovial fluid in the joints. They are rarely found in the foods we eat, as we don’t often eat cartilage or bones! In supplements, glucosamine is often sourced from crustaceans (although vegetarian sources are available), and chondroitin is usually sourced from animal cartilage. They can be found together in supplements, or on their own (primarily glucosamine), or in a combination with other joint-supporting ingredients.
What are glucosamine and chondroitin?
Glucosamine is an amino sugar – this means a sugar (in this case glucose) attached to an amino acid, or ‘amino group’. (By the way, the fact that it contains a sugar molecule doesn’t mean it’s bad for our health!) Glucosamine is the smallest building block for glycosaminoglycans – a group of larger molecules such as chondroitin sulphate and hyaluronic acid that make up the tissues such as cartilage mentioned above. In other words, glucosamine is used to make chondroitin and other similar substances that are then incorporated into cartilage, collagen, bone and so on.
How can they help us?
Glucosamine on its own and glucosamine/chondroitin in supplement form have been widely researched for their potential to support the joints and relieve joint pain, including in osteoarthritis. Clinical trials have had mixed results, but some indicate improvement, for example:
Glucosamine and chondroitin are thought to work primarily by providing the building blocks for cartilage and joint fluid. However, they may also have other effects: for example, glucosamine may help to reduce inflammation too.[3,4]
Food sources of glucosamine and chondroitin
As we said in the summary above, it can be difficult to get a good amount of these substances as part of a normal diet. Probably the best source that we can eat is bone marrow (this is not as strange as may seem – you can buy large bones specifically for this purpose!). Another way of getting these nutrients is to make your own traditional bone broth by simmering leftover bones for a minimum of 8 hours, to make them release as much of the nutrients from the marrow and cartilage as possible. You can then use the broth to make soups or stews in place of ordinary stock, or even as a nourishing drink. Look up ‘how to make traditional bone broth’ online for proper recipes and instructions.
What other nutrients are often taken with glucosamine / chondroitin?
In supplements, you may also find some of the following nutrients together with glucosamine and chondroitin:
Forms and bioavailability
Chondroitin usually only comes in one form – chondroitin sulphate.
Glucosamine is found in two main forms in supplements: glucosamine sulphate and glucosamine hydrochloride.
So which to choose? Our opinion is that there’s no need to specifically choose the hydrochloride form over the sulphate form unless you’re allergic to shellfish or you’re looking for a vegetarian form (check the label carefully as not all hydrochloride forms are suitable for vegetarians).
Single ingredients or combinations?
Another question you might have is whether it’s best to choose glucosamine, combined glucosamine and chondroitin or combinations with other ingredients. There is no easy answer to this!
If you’re vegetarian, then you’ll generally want to avoid products containing chondroitin, as it’s usually sourced from animal cartilage; glucosamine on its own or combined with MSM or plant extracts, can be found in products suitable for vegetarians and vegans.
But should the rest of us take chondroitin? Some research has indicated that chondroitin is not very well absorbed, as it’s such a large molecule. However, other studies have found that it can be absorbed in humans, although potentially at much lower levels than glucosamine – 12% absorption was found in one study, for example. This same study also found chondroitin to have anti-inflammatory and joint-protective effects; and other studies have found combinations of the two ingredients to work well. 
Plant extracts (such as those mentioned above under ‘What other nutrients …’) in combination with glucosamine and/or chondroitin may help by providing anti-inflammatory and antioxidant activity. However, by choosing these products you’re often reducing the amount of glucosamine/chondroitin you get per tablet/capsule, and so some people prefer to take these as a separate supplement.
Dosages: Lifestyle Labs recommendations
Adults: The recommended dose of glucosamine for adults is generally 1,500mg a day – this is the amount that’s been found to be effective in clinical trials. This amount is probably best taken in three 500mg doses throughout the day for optimal absorption. Note that it’s often recommended to take glucosamine for at least three months to assess whether or not it will be helpful – it’s unlikely to have an immediate effect. It is safe long-term at this dosage.
Chondroitin is often recommended at a dose of 1,200mg a day, in three 400mg doses; and again, safe long-term at this dosage.
Children: Glucosamine/chondroitin supplements are not generally used for children other than under the guidance of a practitioner.
If you are taking any medications or have any medical condition, please consult your healthcare practitioner before taking a glucosamine or chondroitin supplement.
For most people, glucosamine and chondroitin are very safe supplements to take on a long-term basis at the advised dosages.
Glucosamine should be taken at 1500 mg once daily dose, based on clinical research.