There is no way of knowing for sure.

I refuse to purchase any GNC product... but you might look at the
inert ingredients listed to see if a filler or something else is in that combo pill.

I don't use combos....I buy single supplements so I can tailor my doses etc. I took ALA many years ago, and it did nothing for me.
I don't recall any side effects but it was a low dose. It used to be ferociously expensive back then, so I gave it up.

I haven't had spectacular results from R-lipoic stabilized either, so I have cut back to twice a week on that one. I had to buy the enteric coated Bromelain for my HAE problem instead with that money. I've also cut back on Benfotiamine, and have seen no difference with that one either. I just bought a new refill bottle of that for vacation, as I sometimes get burning from fish and the sun.

edit to suggest.... you need to keep a journal...and since you love to write, that should be easy for you. You may find a food or alcohol trigger by doing so. Not all symptoms from food come immediately...some are delayed, and a journal might reveal that for you.