Quite a lot of equine joint supplements contain green lipped mussel. Green lipped mussel provides a source of glucosamine, chondroitin, omega-3 fatty acids EPA and DHA , Vitamins C and E, minerals such as zinc, copper, iodine and manganese and a variety of enzymes.
A review in 2021 concluded that New Zealand green-lipped or greenshell™ mussel (GSM) (Perna canaliculus) extract did have some efficacy in people with osteoarthritis (OA).
“The overall analysis showed that GSM provided moderate and clinically meaningful treatment effects on OA pain. However, the current evidence is limited by the number and quality of studies, and further larger and high-quality studies are needed to confirm the effectiveness and to identify the optimal GSM format. Nevertheless, it is worth considering using GSM extracts especially for patients seeking alternative pain relief treatments with fewer side effects compared to conventional treatment.” https://pubmed.ncbi.nlm.nih.gov/33738701/
Dosage: Four studies used a whole extract, with doses ranging from 1050 to 3000 mg/day; Four studies used a lipid extract in doses ranging 210 and 1200 mg/day; Assuming a human weighs 75kg, then these would equate to doses for a 500kg horse of 7 to 20g a day for a whole extract or 1.4 to 8g a day for the lipid extract. So it would be worth checking the method of preparation/extraction (drying versus lipid extraction) and the daily dose of any product.
The product shown above (New Zealand Green Lipped Mussel from Healthy Care Australia) is a dried preparation, according to the website. The recommended human dose is 3 x 500mg per day i.e. 1500mg. This would be in the middle range of the studies in the 2021 review. So for a horse, the feeding rate should be at least 14 capsules a day to 40 capsules per day. That would mean a pot of 250 capsules would last 18 days at the lower feeding rate, 12.5 days at the medium feeding rate (20 capsules per day) and 6.25 days at the higher feeding rate.
There is one study in horses I am aware of. A randomised, double-blinded, placebo-controlled study on the efficacy of a unique extract of green-lipped mussel (Perna canaliculus) in horses with chronic fetlock lameness attributed to osteoarthritis, Cayzer et al. (2012). https://pubmed.ncbi.nlm.nih.gov/21883418/
This study used lyophilised products from green-lipped mussel (Perna canaliculus[LPPC]) – essentially dried mussel. The design and numbers are reasonable. They fed horses 25 mg/kg bwt/day LPPC or placebo for 56 days. 25mg/kg x 500 = 12.5g, so equivalent to 25 capsules of Healthy Care Australia product.
“Results: Clinical evaluation of horses with a fetlock lameness treated with LPPC showed a significant reduction in severity of lameness (P<0.001), improved response to the joint flexion test (P<0.001) and reduced joint pain (P = 0.014) when compared with horses treated with placebo.”
“Conclusions: The LPPC significantly alleviated the severity of lameness and joint pain and improved response to joint flexion in horses with lameness attributable to OA in the fetlock.”
Bottom line – there is some limited evidence for feeding GLM to humans and horses with arthritis. For a horse you probably should be feeding at least 12.5g of dried GLM to a 500kg horse per day to get an effect.
Here are the amounts of GLM in some of the GLM products for horses on the market…
Gold Label GLM only provides 3g (loading) or 1.5g per day (maintenance) ☹
Nupafeed Flex GLM – the amount of GLM not stated ☹
Yumove Joint Care for Horses – 1.4g GLM per day ☹
Maxavita Maxaflex – 1g GLM extract per day ☹
None of these are worth feeding!
