Hello and thanks for researching this important health topic!
When shopping for a 'generic' equivalent of a supplement made for pets, there are a number of things to consider:
1) Make sure that the dose of the human supplement is the same (or can be made the same) as the amount of each ingredient in the pet preparation.
2) Just because a human supplement is available, does not mean that it guarantees the ingredients or the effect...ask the pharmacist at the store where you shop to find out what products people come back to buy again! Sometimes cheap is just cheap.
3) If you see any decrease in your pet's progress, you should return to the pet-tested product that originally helped.
Your concern has touched me--if you have follow-up questions, or need to clarify anything, please let me know right away! Your "Accept" helps me reach out to others!