heya jaz
this is the way it goes: when we are talking about serious dugs (ie pharmacy drugs) they put a use by date on them according to the time taken for any of the following to occur:
1 - 10% of the drug stated on the label degrades
2 - a product of degradation builds up to an intolerable level (will depend on the particular drug of course)
3 - the formulation is compromised (ie a syrup clumps together, tablets fall apart, bla bla bla)
4 - an arbitraty date to discourage people hoarding drugs. (hoarding = bad. its best to seek new professional advice after, oh, 5 years of hanging onto a drug lol)
with sports supplements, there are NO safeguards on them. the company doesnt have to put any use-by on them. the dont do stability testing. they really, honestly dont give a shit. the other reason is that sometimes sports supplements sit on shelves for a long, long, long time before theyre sold, and so from a commercial point of view, companies are reluctant to hamstring their own product using a use by date.
so, to answer your question more directly - no one knows if your product is ok. the company doesnt know, because they didnt test it (it costs an insane amount of money to test drugs for long term stability). an organic chemist could take a guess, but even then, it would be ballpark to the max. however. drugs degrade very slowly if theyre in powder form (in a watery solution, theyre screwed after a year or 2 for sure) and kept in the fridge. SO, if theyve been kept in the fridge for the whole time youve had them, theres a reasonable chance taht theres still going to be a therapeutic effect. for some drugs, 3 years in the fridge is better than a year out on a bench. for others, it doesnt matter much either way. it all comes down to whether or not you want to risk taking it, end of story.
if it were me, a dry drug? for 3 years? yeah. id take it. everyone knows sports supps dont work anyway
so its ok