I have used 4cyte gel on an elderly horse with pretty significant arthritis and low-grade kissing spine. My preferred go-to for arthritis is a green-lipped mussel product as it’s had a fair amount of scientific testing and has been proven to help all sorts of animals with arthritic changes.
The 4cyte granules have green-lipped mussel powder but the gel doesn’t, it’s a different active ingredient. The company has shown studies but only for the granule product, last I checked. I personally take the study with a grain of salt as GLMP has been proven to work by itself anyway, so did the granules show positive results because of their own active ingredient or because of the GLMP in the composition of the product? Who knows. I also personally find it a bit disingenuous that wherever they advertise the gel, in the marketing they push the study of the granules despite it being a totally different product.
I did once come across a “study” for their gel but it only had a few horses as a sample size, was done by a vet that had an affiliation with the company (could definitely be wrong on that, my memory isnt so great on it), and his results were based on him eyeing the horses in a trot-up so not exactly what I’d call thorough. I even contacted the company to enquire about more studies and was told that one was currently being carried out, so I asked if it could please be sent me to when it was complete but I never heard from them.
All that aside, I actually coughed up the $400-ish dollars for a pouch of the gel so that I could give it a try and consider changing my opinion, but for my horse I don’t think it did anything for him. He went backwards so I put him back on a GLMP product and he improved again.
Your mileage may vary but for me I wouldn’t buy the gel again. The stuff also sets hard like glue to any surface it drips on. It’s stuck to my car’s paint, my float’s cupboards, feed tubs, basically anywhere it drips and it’s a nightmare to remove.