Five different food supplements, which are among the mostsold and popular in Spain, were acquired in health food shops anddietetic centers. Capsules#1 containing l-Phe, Capsules#2 having l-Phe (other components: l-carnitine, chrome, citrus aurantium, wildgymnema, and artichoke), Capsules#3 containing l-Phe and l-Tyr(other components: guarana, l-carnitine, chrome and medium-chain triglycerides), Capsules#4 having l-Trp (other components:-aminobutiric acid, magnesium, vitamin B3 and vitamin B6) andTablets#1 containing l-Trp (other components: valerian extractand passion-flower).