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    Botanical ExtractsNatural

    Citrus Aurantium

    Also known as: Bitter orange, Synephrine, p-synephrine, C. aurantium

    Bitter orange peel extract standardised for p-synephrine; selective β-3 adrenergic agonist with minimal β-1/β-2 activity at clinical doses.

    Last reviewed: 2026-06-23 · 1 indexed study

    Evidence Score
    58/100
    ThermogenicFat lossEnergyAppetite suppression
    Data Completeness3/4 · 75%
    Evidence ScoreDosageSafetyLinked Studies

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    Overview

    Citrus aurantium (bitter orange) provides p-synephrine, a beta-3 adrenergic agonist used as a thermogenic and mild stimulant alternative to ephedra.

    Mechanism & Function

    Mechanism of Action

    Stimulates lipolysis via β-3 adrenergic receptors, mildly raises metabolic rate, and may suppress appetite without significant cardiovascular stimulation at recommended doses.

    Physiological Role

    Used in thermogenic and fat-loss formulas; legal alternative to ephedrine with milder profile; UK restrictions apply.

    Primary Pathways

    β-3 adrenergic agonismLipolysis inductionThermogenesisAppetite suppression

    Performance / Health Relevance

    Several RCTs supporting thermogenic and modest fat-loss effects; safety established at 50 mg/day p-synephrine.

    Evidence Review

    Overall58/100
    Human Clinical62/100
    Meta-Analysis52/100
    Mechanistic78/100
    Real-World58/100
    Safety72/100

    Practical Use & Dosage

    Minimum Effective Dose
    25 mg p-synephrine
    Optimal Range
    50 mg p-synephrine/day
    Upper / Caution Level
    ~100 mg p-synephrine/day
    Timing
    Pre-exercise or AM
    Best Format
    Capsule, powder
    Bioavailability
    High oral bioavailability.
    Absorption Considerations
    Rapid absorption; Tmax ~1 h; half-life ~3 h.

    Safety & Interactions

    Side Effects

    • •Mild BP/HR elevation
    • •Anxiety
    • •Insomnia
    • •Headache

    Contraindications

    • Hypertension
    • Cardiac arrhythmias
    • Pregnancy
    • MAOI use

    Drug Interactions

    • •MAOIs
    • •Stimulants
    • •Antihypertensives
    • •Caffeine (additive)

    Who Should Avoid

    • •Cardiovascular disease
    • •Anxiety disorders
    • •Pregnancy

    Monitoring

    BP and HR.

    Frequently Asked Questions

    Auto-generated from indexed evidence — dosage, safety, interactions, and more.

    When is Citrus Aurantium typically used or indicated?

    Citrus Aurantium is most commonly used for: Thermogenic, Fat loss, Energy, Appetite suppression. Used in thermogenic and fat-loss formulas; legal alternative to ephedrine with milder profile; UK restrictions apply.

    How does Citrus Aurantium work?

    Stimulates lipolysis via β-3 adrenergic receptors, mildly raises metabolic rate, and may suppress appetite without significant cardiovascular stimulation at recommended doses.

    What is the recommended dose of Citrus Aurantium?

    The optimal range is 50 mg p-synephrine/day. with a minimum effective dose of 25 mg p-synephrine. Best taken: Pre-exercise or AM. Upper / caution level: ~100 mg p-synephrine/day.

    What are the side effects of Citrus Aurantium?

    Reported side effects include: Mild BP/HR elevation; Anxiety; Insomnia; and Headache. Monitoring: BP and HR.

    Does Citrus Aurantium interact with medications?

    Known or theoretical interactions: MAOIs; Stimulants; Antihypertensives; and Caffeine (additive). Always check with a clinician before combining with prescription medication.

    Who should avoid Citrus Aurantium?

    Citrus Aurantium is generally not recommended for: Cardiovascular disease; Anxiety disorders; Pregnancy; Hypertension; Cardiac arrhythmias; Pregnancy; and MAOI use.

    How strong is the evidence for Citrus Aurantium?

    Evidence level: Moderate (overall score 58/100), based on 1 indexed study on SuppIndex.

    Research & References (1)

    p-Synephrine and thermogenesis: systematic review and meta-analysis

    Meta-Analysis2017Moderate
    PubMed

    Significant increase in RMR (~6.9%) and lipolysis without significant cardiovascular effects.

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    Research Overview

    Moderate Evidence
    1Total Studies
    0Human Trials
    1Meta-Analyses
    2017Latest Study
    0Animal / In Vitro
    0Athlete Studies
    Primary data sourceMixed
    Pooled evidence (meta-analysis / systematic review)Yes

    Cite this ingredient

    One-click citation export in APA, MLA, Chicago, BibTeX, or HTML. The URL below is stable and safe to link.

    Stable URL

    https://thesuppindex.com/ingredients/citrus-aurantium

    SuppIndex. (2026). Citrus Aurantium: Evidence summary, dosage and clinical studies. Retrieved October 16, 2026, from https://thesuppindex.com/ingredients/citrus-aurantium

    Based on 1 indexed studies · Evidence level: Moderate.

    Goal Ratings

    Fat Loss
    Endurance
    Focus

    Stack Compatibility

    Synergistic with caffeine; pair with green tea, l-tyrosine for thermogenic stack.

    Caffeine AnhydrousGreen Tea ExtractL-Tyrosine