Can You Take DL-Phenylalanine and L-Phenylalanine Together?

Use extra care with this pair

The short answer

DL-Phenylalanine contains L-Phenylalanine as its L-isomer component. Taking both simultaneously provides a double dose of L-Phenylalanine, which may lead to excessive dopamine and norepinephrine production.

How to arrange timing

Avoid combining DL-Phenylalanine with additional L-Phenylalanine as the total phenylalanine dose may be excessive.

Reference

Reference noted for this combination: NIH Office of Dietary Supplements – Amino Acids. https://ods.od.nih.gov/

Important context

Whether supplements suit you together also depends on dose, product formulation, health conditions, and medication use. Ask a doctor or pharmacist first if you take medication, are pregnant or breastfeeding, or have a chronic condition.