Human joint supplement for horse?

[Woodrock]

My elderly retired horses has just burnt through $130 of equine joint supplement in 3wks. I found a human joint supplement that is much cheaper & contains very similar ingredients & is a less than a quarter of the price. Anyone else tried a human supplement on their horse?

 

[TheMule]

My elderly retired horses has just burnt through $130 of equine joint supplement in 3wks. I found a human joint supplement that is much cheaper & contains very similar ingredients & is a less than a quarter of the price. Anyone else tried a human supplement on their horse?

Horse and human joints are constructed the same so in theory it would work.
The amount you'd need to feed a horse (probably around 8x more, dependent on size) would probably make it prohibitively expensive- check how much of each thing is included