supplements

Protein powder, protein foods, and pre-digest proteins contain plenty of amino acids, including BCAA's. I was never big on taking free form amino acids. I think L-glutmine and L-arginine have been the biggest "hyped" amino acids of all time.

Some amino acids like GPLC of course have been shown to be promising.

Of course the company's selling these free form amino acids will try to convince you every which way but loose that you "need" these amino acids because of what they are "responsible for".

But I tell my customers I would rather see then spend more money on buying more quality protein like super plasma or peptopro than dropping $30 on some L-Glutamine

Yup, given you're taking good quality protein and eating a healthy and relatively balanced diet, you should be getting most of those in plentiful supply already.