Be aware that the U.S. Food and Drug Administration does not strictly regulate herbs and dietary supplements. There is no guarantee of strength, purity or safety of products containing or claiming to contain niacin. Decisions to use herbs or supplements should be carefully considered. Individuals using prescription drugs should discuss taking herbs or supplements with a pharmacist or health care professional before starting.
Multiple studies report benefits of the use of chondroitin by mouth in patients with osteoarthritis of the knee and other locations (spine, hips, finger joints), with improvement of symptoms (such as pain) and function (such as mobility) and reduced medication requirements (such as anti-inflammatories). However, most studies have been brief (six months' duration) with methodological weaknesses. Despite these weaknesses, the scientific evidence points to a beneficial effect when chondroitin is used for six to 24 months. Longer-term effects are not clear. Full effects may take several weeks to occur.
Chondroitin is frequently used with glucosamine, which has independently been shown to benefit patients with osteoarthritis (particularly of the knee). It is not clear if there is added benefit of using these two supplements together compared to using either alone.
Eye conditions (ophthalmologic use)
Chondroitin is sometimes used as a component of eye solutions to treat keratoconjunctivitis, corneal preservation and intraocular pressure. These solutions should be used only under the supervision of an ophthalmologist.
Heart attack prevention in people with heart disease
The quality of research in this area is poor, and no clear recommendation can be made.
There is not enough research in this area to make a clear recommendation.
There is promising early research in this area, but more evidence is necessary before a clear recommendation can be made.
Chondroitin has been suggested for many other uses, based on tradition or on scientific theories. However, these uses have not been thoroughly studied in humans, and there is limited scientific evidence about safety or effectiveness. Some of these suggested uses are for conditions that are potentially very serious and even life-threatening. You should consult a health care provider before taking chondroitin for any unproven use.
Chronic venous ulcers
Deep intraosseous defects
Dry eye syndrome
Iron deficiency anemia
Premature labor prevention
Interactions with drugs, herbs and other supplements have not been thoroughly studied. The interactions listed below have been reported in scientific publications. If you are taking prescription drugs, speak with your health care provider or pharmacist before using herbs or dietary supplements.
Interactions With Drugs
In theory, chondroitin may increase the risk of bleeding when taken with drugs that increase the risk of bleeding. Some examples include aspirin, anticoagulants (blood thinners) such as warfarin (Coumadin) or heparin, and antiplatelet drugs such as clopidogrel (Plavix).
Interactions With Herbs And Dietary Supplements
Based on preliminary data, chondroitin may increase iron absorption. In theory, chondroitin may increase the risk of bleeding when taken with herbs and supplements that are believed to increase the risk of bleeding. Multiple cases of bleeding have been reported with the use of ginkgo biloba, and fewer cases with garlic and saw palmetto. Numerous other agents may theoretically increase the risk of bleeding, although this has not been proven in most cases. Some examples include alfalfa, American ginseng, angelica, anise, Arnica montana, asafetida, aspen bark, bilberry, birch, black cohosh, bladderwrack, bogbean, boldo, borage seed oil, bromelain, capsicum, cat's claw, celery, chamomile, chaparral, clove, coleus, cordyceps, dandelion, danshen, devils claw, dong quai, EPA (eicosapentaenoic acid, found in fish oils), evening primrose oil, fenugreek, feverfew, fish oil, flaxseed or flax powder (not a concern with flaxseed oil), ginger, grapefruit juice, grapeseed, green tea, guggul, gymnestra, horse chestnut, horseradish, licorice root, lovage root, male fern, meadowsweet, melatonin, nordihydroguairetic acid (NDGA), omega-3 fatty acids, onion, papain, panax ginseng, parsley, passionflower, poplar, prickly Ash, propolis, quassia, red clover, reishi, Siberian ginseng, sweet clover, rue, sweet birch, sweet clover, turmeric, vitamin E, white willow, wild carrot, wild lettuce, willow, wintergreen and yucca.
The doses listed below are based on scientific research, publications or traditional use. Because most herbs and supplements have not been thoroughly studied or monitored, safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients even within the same brand. Combination products often contain small amounts of each ingredient and may not be effective. Appropriate dosing should be discussed with a health care provider before starting therapy; always read the recommendations on a product's label. The dosing for unproven uses should be approached cautiously, because scientific information is limited in these areas.
Adults (Aged 18 Or Older)
Children (Younger Than 18): There is not enough research to know if chondroitin is safe or effective in children.
Chondroitin sulfate has been suggested as a treatment for multiple conditions. The currently available research supports the use of chondroitin by mouth for osteoarthritis (knee, spine, hips, finger joints). Chondroitin is also included in a number of commercially available eye solutions, which should be used only under the supervision of a physician. There is not enough scientific evidence to support the use of chondroitin for any other medical condition. In theory, chondroitin may increase the risk of bleeding, and allergic skin reactions have been reported rarely. Chondroitin should be avoided in pregnant or breast-feeding women and in children. Consult your health care provider immediately if you have any side effects.
The information in this monograph was prepared by the professional staff at Natural Standard, based on thorough systematic review of scientific evidence. The material was reviewed by the Faculty of the Harvard Medical School with final editing approved by Natural Standard.
Selected Scientific Studies: Chondroitin
Selected studies are listed below:
Last updated August 29, 2005