I want to boost dopamine level. So what's the difference among the three supplement : L Tyrosine, L-Dopa (Mucuna) and L-Phenylalanine?

Amino acids. These are different amino acids your body can use to make other amino acids. Most people want to boost their dopamine level in the brain, it is not clear that taking supplements can do this. What is you goal, actually? It would be better to start there.
DA = dopamine. Please repost your question with an explanation of how & why you think you don't have enough DA. DA in the bloodstream drives up your blood pressure. DOPA in the bloodstream causes intractable nausea & vomiting. Your brain is walled off from the rest of your system by the blood-brain barrier (BBB), so it's safe from any harebrained notions you may have about monkeying with your neurotransmitters.

Related Questions

Is it safe to take n-acetyl l-tyrosine and the supplement l-dopa (mucuna) together to support and boost dopamine production?

Yes. Yes, it is perfectly safe to take n-acetyl-l-tyrosine and l-dopa together. Adequate sleep, exercise and a healthy diet can also increase Dopamine production. See http://www.Wikihow.Com/increase-dopamine and http://www.Peaktestosterone.Com/natural_dopamine_increasers.Aspx for more info. Read more...
Please repost. Dopamine (DA) is produced by certain brain neurons in response to excitation by other neurons. DA metabolism is fantastically complicated & highly regulated. It doesn’t just “increase” in an unregulated way. Please repost & explain why you think your DA production NEEDS boosting; what tests or measurement techniques have been used to determine this; & what you expect to achieve by “boosting” DA. Read more...