#Supplement scams examples:

Testosterone boosters
Glutamine (works only if your body need it, if your diet is protein rich glutamine doesn't work)
BCAA (works only if you are on low calorie diet, only if your body need it/ If your diet is protein rich, BCAA's effect is weak).
L-carnitine (doesn't work for some people)
“Advanced” Creatine formulas (standard creatine is good enough and is much cheaper).
Proteins witrh added cheap amino acids. Cheapest amino acids are taurine and glutamine.

More exmples in https://examine.com/ and here: http://seannal.com/articles/supplementation/5-popular-bodybuilding-supplements-avoid.php ping +Sean Nalewanyj