Skip to content
    Back to Database
    Ergogenic CompoundsNatural

    Fructose

    Also known as: D-Fructose, Fruit sugar

    Absorbed via GLUT5, fructose is preferentially metabolised by the liver via fructolysis; produces minimal insulin response and replenishes hepatic glycogen efficiently.

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

    Evidence Score
    70/100
    Liver glycogen replenishmentEndurance dual-carb fuelingHepatic carbohydrate source
    Data Completeness3/4 · 75%
    Evidence ScoreDosageSafetyLinked Studies

    Set your location for accurate regulatory status

    Saved on this device — no sign-in needed.

    Sign in to add to stack

    Overview

    Fructose is a monosaccharide that uses the GLUT5 intestinal transporter, allowing it to be co-ingested with glucose to raise total carbohydrate oxidation during prolonged exercise.

    Mechanism & Function

    Mechanism of Action

    Supplies liver glycogen substrate, increases total exogenous carbohydrate oxidation when combined with glucose, and reduces GI distress vs single-transporter loads.

    Physiological Role

    Critical for endurance athletes targeting >60 g/h carbohydrate intake — 2:1 or 1:0.8 glucose:fructose ratios are validated to push oxidation rates to 1.5–1.75 g/min.

    Primary Pathways

    GLUT5 intestinal transportHepatic fructolysisHepatic glycogen synthesis

    Performance / Health Relevance

    Validated in ultra-endurance, ironman, and ultra-marathon athletes for high-rate carbohydrate strategies; reduces GI symptoms vs glucose-only at matched grams.

    Evidence Review

    Overall70/100
    Human Clinical80/100
    Meta-AnalysisN/A

    No meta-analyses or systematic reviews indexed for this ingredient yet.

    Mechanistic80/100
    Real-World72/100
    Safety80/100

    Dimensions marked N/A have no indexed evidence of that class. They are shown as unavailable rather than scored.

    Practical Use & Dosage

    Minimum Effective Dose
    15 g/h alongside glucose
    Optimal Range
    30 g/h fructose + 60 g/h glucose (1:2)
    Upper / Caution Level
    ~50 g/h fructose
    Timing
    Intra-workout
    Best Format
    Powder, gels, drinks
    Bioavailability
    GLUT5-dependent; chronic training upregulates GLUT5 expression.
    Absorption Considerations
    Separate transporter from glucose enables higher combined oxidation.

    Safety & Interactions

    Side Effects

    • •Bloating at high single doses
    • •Loose stools if >50 g/h

    Contraindications

    • Hereditary fructose intolerance
    • Fructose malabsorption

    Drug Interactions

    • •None significant

    Who Should Avoid

    • •IBS patients with FODMAP sensitivity

    Monitoring

    None.

    Frequently Asked Questions

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

    When is Fructose typically used or indicated?

    Fructose is most commonly used for: Liver glycogen replenishment, Endurance dual-carb fueling, Hepatic carbohydrate source. Critical for endurance athletes targeting >60 g/h carbohydrate intake — 2:1 or 1:0.8 glucose:fructose ratios are validated to push oxidation rates to 1.5–1.75 g/min.

    How does Fructose work?

    Supplies liver glycogen substrate, increases total exogenous carbohydrate oxidation when combined with glucose, and reduces GI distress vs single-transporter loads.

    What is the recommended dose of Fructose?

    The optimal range is 30 g/h fructose + 60 g/h glucose (1:2). with a minimum effective dose of 15 g/h alongside glucose. Best taken: Intra-workout. Upper / caution level: ~50 g/h fructose.

    What are the side effects of Fructose?

    Reported side effects include: Bloating at high single doses; and Loose stools if >50 g/h. Monitoring: None.

    Does Fructose interact with medications?

    Known or theoretical interactions: None significant. Always check with a clinician before combining with prescription medication.

    Who should avoid Fructose?

    Fructose is generally not recommended for: IBS patients with FODMAP sensitivity; Hereditary fructose intolerance; and Fructose malabsorption.

    How strong is the evidence for Fructose?

    Evidence level: Moderate (overall score 70/100), based on 1 indexed study on SuppIndex.

    Research & References (1)

    Superior endurance performance with ingestion of multiple transportable carbohydrates

    RCT2008Strong
    PubMed

    Glucose+fructose blend improved time trial performance by 8% vs glucose alone.

    Related Ingredients

    Other top-rated ingredients in Ergogenic Compounds.

    Creatine Monohydrate

    94/100

    A naturally occurring nitrogenous organic acid that facilitates recycling of adenosine triphosphate (ATP) in muscle and brain tissue via the phosphocreatine shuttle.

    Maltodextrin

    78/100

    Short-chain α-1,4 linked glucose polymer that is rapidly hydrolysed by brush-border maltase to glucose; near-equivalent glycaemic response to glucose but lower osmolality at concentration.

    Cyclic Dextrin (HBCD)

    72/100

    Produced via cyclic-glucanotransferase action on amylopectin, HBCD forms cluster-like macromolecules ~160 kDa that solubilise at low osmolality (≈4 mOsm/L) and clear the stomach faster than maltodextrin or glucose polymers.

    Research Overview

    Moderate Evidence
    1Total Studies
    1Human Trials
    0Meta-Analyses
    2008Latest Study
    0Animal / In Vitro
    1Athlete Studies
    Primary data sourceAthletes
    Pooled evidence (meta-analysis / systematic review)No
    Athlete-specific data1 studies

    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/fructose

    SuppIndex. (2026). Fructose: Evidence summary, dosage and clinical studies. Retrieved October 16, 2026, from https://thesuppindex.com/ingredients/fructose

    Based on 1 indexed studies · Evidence level: Moderate.

    Goal Ratings

    Endurance
    Recovery

    Stack Compatibility

    Always combine with glucose/maltodextrin for endurance; pair with sodium and caffeine.

    MaltodextrinHBCDSodium