Can you share with us what are the products you've been disappointed with?
I'd rather not, if only because some of the stuff isn't even made anymore (big surprise). I stick to basically one brand lately and even then, I sometimes wonder. Remember, the supplement industry has NO regulation. That means there's NO guarantee that what's on the label is IN the product.
Some products some time ago used third party research to test their products, but it seems the trend is reversed.
I'm pretty much off ALL supps lately. I just buy the best quality food I can afford.
But I'm always interested in products that have proper scientific tests behind them, by legitimate labs such as universities.