L-Phenylalanine is the natural L-isomer of the essential amino acid phenylalanine, different from DL-Phenylalanine (DLPA) or D-Phenylalanine. Your body gets it from protein-rich foods and uses it to build proteins.
Most people take L-Phenylalanine on an empty stomach to help absorption. The body turns it into tyrosine, which then converts into dopamine and norepinephrine, neurotransmitters that affect brain function and mood. Start with a lower dose to see how you respond.
Do not use L-Phenylalanine if you have phenylketonuria (PKU). High doses or combining it with certain medications, such as MAOIs, can cause problems. Consult a professional before using any supplement.