What are the pros and cons of oral joint supplements?
Joint supplements are in a category described as nutraceuticals. The word nutraceutical was developed for oral compounds that were neither nutrients nor pharmaceuticals. Nutraceuticals therefore because they are not a food, food additive nor drug are not regulated by the Food and Drug Administration (FDA) of the USA. Therefore, there is no premarket approval process and neither safety, efficacy nor manufacturing is assured. In addition, currently no mechanism (other than voluntary) exists to hold a manufacturer accountable for the labeling of a novel ingredient. For example, the label may say that the product contains 500 mg/oz of chondroitin sulfate when in actuality it may only contains 50 mg. Chondroitin sulfates, an expensive ingredient of many joint supplements have been found to offer an example of consistent mislabeling. A study, funded by Nutramax Laboratories, found deviations from label claims for chondroitin sulfates in 84% (9/11) of the products studied, the amount by which products were mislabeled ranged from 0-115%. 

In addition to mislabeling, the safety of the product is not well regulated.  Manufacturers of nutraceuticals are not mandated to report adverse effects; therefore lack of adverse events should not be interpreted as evidence of safety. Studies are continually being performed by independent labs on the efficacy of joint supplements but the costs are expensive. For example, the College of Veterinary Medicine, Michigan State University performed a study in 2002 that found that horses with hock arthritis (distal joints) had a significant reduction in gait asymmetry after receiving oral joint supplements for 2 weeks.

ArthriEase-GOLD was developed by veterinarians for veterinarians. Garmon Manufacturing guarantees it's products purity and stands by its claims with a money-back guarantee.

Chondroitin sulfate – Chondroitin sulfate is a sulfated glycosaminoglycan that is a major structural component of cartilage and provides much of its resistance to compression. Most chondroitin appears to be made from extracts of cartilaginous cow and pig tissues (cow trachea and pig ear and nose), but other sources such as shark, fish and bird cartilage are also used.  Along with glucosamine, chondroitin sulfate has become a widely used dietary supplement for treatment of osteoarthritis.  Chondroitin sulfate is thought to be a building block for cartilage, that may counteract inflammation, and protect against cartilage degradation. Chondroitin sulfate appears to be very safe in normal animals. Chondroitin sulfate is not well absorbed due to it’s large molecular size, but levels of chondroitin sulfate appear to build up in the body over time. Therefore, one dose of chondroitin sulfate may not be effective, but multiple doses may reach effective levels.

Glucosamine hydrochloride/glucosamine sulfate - Glucosamine is thought to help in the production of cartilage, and it may have anti-inflammatory effects and prevent cartilage breakdown. In addition, glucosamine sulfate may act as a source of sulfur. Glucosamine appears to be safe in normal animals.          

MSM - MSM (methylsulfonylmethane) MSM may have anti-inflammatory effects or alter immune responses. Another theory proposes that MSM may be a source of sulfur, which is essential for cartilage and joint health. Although the reason for its effect is unknown, MSM may be beneficial in managing inflammatory or immune-mediated problems, and it appears to be safe to use.

Hyaluronic Acid (Hyaluronan) - The backbone of the joint lubrication fluid is known as hyaluronic acid.  Hyaluronan is naturally found in many tissues of the body such as skin, cartilage, and the vitreous humor (eye). In addition, Hyaluronan can be injected into joints or given intravenously. Given in these ways it has been shown to have anti-inflammatory results and improve lameness by improving joint viscosity & soft tissue lubrication. Although, the oral form has questionable efficacy based on the fact that hyaluronan is such a large molecule, oral absorption is questionable.