Historically, a human being was not necessarily a natural person in some jurisdictions where a slave was a thing (subject of a property right) rather than a person. In many cases, fundamental human rights are implicitly granted only to natural persons.
Phenylalanine amino acid > Tyrosine amino acid > L-Dopa > Dopamine > Norepinephrine > Epinephrine. Mucuna pruriens is an herb that contains a small percentage of natural L Dopa. Mucuna pruriens is available without a prescription. For more information on mucuna pruriens and levodopa, click on the link provided.
Certain vegetables in particular are excellent sources of amino acids that stimulate dopamine production. For example, beets supply the amino acid called betaine, that aids in the regulation neurotransmitters like dopamine. Artichokes and avocados have also been found to increase dopamine levels.