Can You Take Caffeine and DL-Phenylalanine Together?

Use extra care with this pair

The short answer

DL-Phenylalanine provides precursors for dopamine and norepinephrine synthesis (via L-phenylalanine) and inhibits enkephalinase (via D-phenylalanine). Caffeine amplifies catecholamine signaling. Together they may cause excessive stimulation.

How to arrange timing

Start with low doses when combining DL-Phenylalanine and caffeine. Monitor for jitteriness, anxiety, or elevated heart rate.

Reference

Reference noted for this combination: Examine.com – Phenylalanine. https://examine.com/supplements/phenylalanine/

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.