Why You — and Your Dog — Should Be Taking Glucosamine

"People typically report reductions in pain and swelling of the joints," says Hoffman. "As far as whether it works consistently, the jury is still out on this. Clinical trials have had mixed results, with some reporting benefits, while others have not. Anecdotally, I have had patients who swear by it and others that saw no benefit. One of the other issues that was widely reported is in relation to the quality of the ingredients. One study pointed out that in 10 of the glucosamine products they reviewed, some showed up to 50 percent fillers added. Essentially, you would be getting half the required dose to get any benefits, so I feel that more research is needed."

When it comes to glucosamine use in dogs, Greenstein says there currently is no overwhelming evidence of effectiveness. However, she adds, that may well evolve as research continues. "In order to say something is 'good' for our animal patients, there has to be robust scientific proof of efficacy and safety," says Greenstein. "The science of joint health is actually extremely complex. Individual cartilage cells, called chondrocytes, aren't well supplied by a network of blood vessels the way that other tissues are. This means they can only obtain their nutrients by absorbing them from surrounding tissue. So, adding extra cartilage building blocks to the circulation is thought to favor cartilage production, but this is a bit of an oversimplification.

"There are some studies that show a modest benefit for arthritis, but overall the research in veterinary medicine is still lacking," she adds. "There is considerable debate as to the oral bioavailability of some forms of glucosamine; basically, how much active ingredient of an oral product actually reaches the target tissue in the joints and how efficacious it is. Some studies have shown promising but mild positive effects, but more research is certainly needed."

Dog and human formulations often differ in terms of the chemical formulation of glucosamine, including glucosamine hydrochloride, glucosamine sulfate and crystalline glucosamine sulfate. "These forms vary significantly in their efficacy and oral bioavailability," says Greenstein. "Most glucosamine supplements for dogs are glucosamine hydrochloride, which is a different chemical variant than is typically used for people. Glucosamine sulfate in human formulations is sometimes combined with other salts, like sodium or potassium chloride. Some might argue these salts could be risky for dogs with heart or kidney disease and should be avoided, but this has not been proven."

Human glucosamine products often contain other additives and active ingredients that shouldn't be assumed to be safe for dogs, she adds. For instance, artificial sweeteners like xylitol that can be found added to some human supplements, can actually be fatally toxic to dogs. "It's important to point out that supplements or nutraceuticals like glucosamine are not as tightly regulated as medications," says Greenstein. "There have been issues with quality control and ingredient lists that don't match the actual contents of a product."

According to Sara Ochoa, a veterinary consultant for DogLab, the human version of glucosamine may be too much for little dogs, and many dogs don't like the taste of the gel capsule. "Human glucosamine usually comes in gel capsules," she says in an email interview. "Most dogs don't easily take these capsules. Glucosamine for dogs comes in the form of a treat. Most dogs love taking these supplements." The reason for this: Dogs have a shorter digestive system than humans, so the supplement needs to be broken down faster before it leaves their body. Chewable tablets, soft chews and liquids all break down quickly, allowing dogs to readily absorb the nutrients and reap the benefits.

Lastly, many high-quality canine supplements also are fortified with other minerals that aid in relief from joint pain for your dog that wouldn't necessarily be present in human supplements. Among them: Ascorbic acid, which is essential for the absorption of glucosamine in your dog's body, thereby upping the effectiveness of the other ingredients.

To get the best effect, Hoffman says people should consider 1,500 mg of a good-quality glucosamine sulfate and combine that 1,200 mg of chondroitin sulfate (another ingredient in joint tissue derived from shark cartilage). "They work better together," he says, adding that it can take anywhere from three to eight weeks to see any benefits.

According to Greenstein, appropriate glucosamine dosing information for dogs is surprisingly sparse and no clear consensus exists. "This is likely a result of confusion from different studies using different formulations," she says. "Recent studies do demonstrate varying oral bioavailability between liquid versus tablet forms, but this also depends on whether glucosamine hydrochloride or glucosamine sulfate are being used."

Ochoa suggests that dog owners follow the dosage guidelines listed on the supplement package. "A typical dosage is about 5 mg per pound of body weight," she says. "Glucosamine usually comes in a capsule form that you can squeeze onto your dog food or in a taste treat that your dog can eat."

Research suggests that specific forms of glucosamine also might help suppress changes that trigger irritable bowel disease, dampen the immune response that leads to autoimmune reactions and improve knee mobility after a sports injury, but more research is needed, says Hoffman. "In my clinic," he says, "I don't use glucosamine/chondroitin too much, except in combination with other treatment therapies that I have had success with and have very solid science, such as acupuncture, essential fatty acids, Curcumin, SPMs and CBD oils, as well as counseling patients on weight loss and following an anti-inflammatory diet.

"Treating the body naturally with supplements, herbs or other therapies is done by treating the individual and each person's unique constitution," he adds. "The goal is to help your body heal itself by addressing the root cause. It is only through this philosophy that I have achieved amazing results with thousands of patients. Supplements are not regulated, per se, so always consult a qualified healthcare professional who knows how to use them and can guide you on the best path to healing."

As for canines, glucosamine has been studied in dogs recovering from orthopedic surgery, arthritis, back problems and many other mobility issues. "There are a number of theoretical benefits worth exploring, but more research is needed," says Greenstein. "Increased interest in nutraceutical use in pets is paving the way for some exciting research for other compounds like omega fatty acids, which are showing some promise in helping to manage a variety of conditions ranging from arthritis to kidney to skin disease."

Adds Ochoa: "Glucosamine's anti-inflammatory property also makes it great to use for gastroenteritis or any other type of GI inflammation."

Originally Published: Sep 14, 2020