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evidence · mechanism · dose
Supplements/Amino Acid

DL-Phenylalanine

Catecholamine precursor with mild analgesic properties.

Mood & Anxiety

Overview

Catecholamine precursor with mild analgesic properties.

Natural sources
    Common forms

      Mechanism of action

      L-form is a tyrosine precursor; D-form inhibits enkephalinase.

      Pathways

        Effects on the body

        Organ system effects

        Evidence-based benefits

        Modest analgesic and antidepressant effects

        Limited evidence

        Potential side effects

        Common
        • · GI upset
        Rare
          Serious
          • · Avoid in PKU

          Drug interactions

          MAOIs
          Hypertensive crisis risk.
          severe

          Supplement interactions

          Pairs well with

          None listed.

          Avoid combining with

          No specific avoidances listed.

          Dosing & bioavailability

          Typical dose
          500–1500 mg
          With food?
          Empty stomach

          Where to buy

          Affiliate-style search links to reputable retailers. We don't endorse specific brands — verify third-party testing (USP, NSF, Informed Sport) before purchase.

          Amino Acid
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          iHerb
          Global delivery · curated brands
          Amino Acid
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          Thorne
          Practitioner-grade · NSF tested

          Scientific evidence (8)

          CohortArch Psychiatr Nervenkr · 1979

          DLPA for depression

          Beckmann H, et al.

          Open trial in 27 depressed patients.

          Key findings

          Substantial improvement in 12/27 patients.

          Open study
          Systematic reviewPubMed (NLM) · 1970

          PubMed: DL-Phenylalanine — Modest analgesic and antidepressant effects

          Live PubMed search

          Live results for "DL-Phenylalanine Modest analgesic and antidepressant effects" across the PubMed/MEDLINE peer-reviewed index.

          Key findings

          Opens current human and preclinical literature matching DL-Phenylalanine and "Modest analgesic and antidepressant effects". Filter by RCT, meta-analysis, or year on the results page.

          Open study
          Systematic reviewPubMed (NLM) · 1970

          PubMed: DL-Phenylalanine — randomized controlled trial

          Live PubMed search

          Live results for "DL-Phenylalanine randomized controlled trial" across the PubMed/MEDLINE peer-reviewed index.

          Key findings

          Opens current human and preclinical literature matching DL-Phenylalanine and "randomized controlled trial". Filter by RCT, meta-analysis, or year on the results page.

          Open study
          Systematic reviewPubMed (NLM) · 1970

          PubMed: DL-Phenylalanine — meta-analysis

          Live PubMed search

          Live results for "DL-Phenylalanine meta-analysis" across the PubMed/MEDLINE peer-reviewed index.

          Key findings

          Opens current human and preclinical literature matching DL-Phenylalanine and "meta-analysis". Filter by RCT, meta-analysis, or year on the results page.

          Open study
          Systematic reviewPubMed (NLM) · 1970

          PubMed: DL-Phenylalanine — pharmacokinetics

          Live PubMed search

          Live results for "DL-Phenylalanine pharmacokinetics" across the PubMed/MEDLINE peer-reviewed index.

          Key findings

          Opens current human and preclinical literature matching DL-Phenylalanine and "pharmacokinetics". Filter by RCT, meta-analysis, or year on the results page.

          Open study
          Systematic reviewPubMed (NLM) · 1970

          PubMed: DL-Phenylalanine — safety adverse events

          Live PubMed search

          Live results for "DL-Phenylalanine safety adverse events" across the PubMed/MEDLINE peer-reviewed index.

          Key findings

          Opens current human and preclinical literature matching DL-Phenylalanine and "safety adverse events". Filter by RCT, meta-analysis, or year on the results page.

          Open study
          Systematic reviewPubMed (NLM) · 1970

          PubMed: DL-Phenylalanine — dose response

          Live PubMed search

          Live results for "DL-Phenylalanine dose response" across the PubMed/MEDLINE peer-reviewed index.

          Key findings

          Opens current human and preclinical literature matching DL-Phenylalanine and "dose response". Filter by RCT, meta-analysis, or year on the results page.

          Open study
          Systematic reviewGoogle Scholar · 1970

          Google Scholar: DL-Phenylalanine — clinical evidence

          Live Scholar search

          Cross-database citation index for DL-Phenylalanine as it relates to "clinical evidence".

          Key findings

          Includes preprints, theses, and journal articles. Useful for tracking citation counts and follow-on work.

          Open study
          Educational use only. This profile is not medical advice. Consult a qualified healthcare professional before starting any supplement, especially if you take prescription medication or have a chronic condition.