Pharmacology The rate limiting step for norepinephrine synthesis is: A Conversion of phenylalanine to tyrosine B Conversion of tyrosine to DOPA C Conversion of DOPA to dopamine D Conversion of dopamine to norepinephrine 💡 Explanation The rate limiting step for norepinephrine synthesis is: ✓ Correct Answer: B. Conversion of tyrosine to DOPA