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    Ingredient guide · Ingredient reference

    Is IGF-1 legal? Prescription treatment, supplements and sport

    IGF-1 cannot be classified with one worldwide legal answer. In the United States, mecasermin is a prescription medicine with specific approved indications. Sport rules are separate: IGF-1 is prohibited at all times under the anti-doping guidance inspected here. A supplement listing online does not establish lawful sale, safe use or permission to compete.

    Read the evidence ↓

    Supplement Science Insights Editorial Team

    Published September 23, 2026

    Prescription approval is specific

    The current U.S. Increlex label describes treatment of selected pediatric growth-failure disorders, not general performance enhancement. A lawful medical prescription and the approval of a particular product do not authorize every product sold using IGF-1 terminology. Country-specific prescribing and supply rules still apply. [1]

    Anti-doping permission is a different question

    USADA lists IGF-1 as prohibited at all times. Athletes must check their governing rules and any required therapeutic-use process before using a medicine, even when prescribed. A medical indication does not automatically remove an anti-doping obligation. [2][3]

    Do not equate antler velvet with a blanket ban or clearance

    OPSS distinguishes deer-antler velvet itself from IGF-1: velvet is not explicitly prohibited under the cited rules, but a product may contain prohibited IGF-1. Without adequate testing, its label cannot resolve that uncertainty. Different organizations also have their own prohibited-ingredient policies. [4]

    Check the exact product and jurisdiction

    Imagine an online seller calls a vial a research product or a natural supplement. That wording is not proof of approval for human use. Verify the medicine with a licensed clinician or pharmacist and, for competition, the relevant anti-doping authority before relying on the seller’s description. [1][2][5]

    Hypothetical example — separate hypothetical IGF-1 permission questions
    QuestionInterpretation
    U.S. prescription medicineSpecific product and indication
    Sports participationSeparate anti-doping requirements
    Antler labelDoes not establish absence of IGF-1
    Online availabilityNot legal or safety verification
    Is IGF-1 legal? Prescription treatment, supplements and sport — original article outline diagram
    Original editorial diagram of this article’s sections; no product photograph or clinical finding is depicted.

    Sources for this article

    1. These highlights do not include all the information needed to use INCRELEX ®safely and effectively. See full prescribing information for INCRELEX ®. INCRELEX ®(mecasermin) injection, for subcutaneous use Initial U.S. Approval: 2005
      Source consulted: 2026-09-21. This is a reference resource, not a claim that we conducted the studies or tested a product.
    2. Screen Your Dietary Supplements | U.S. Anti-Doping Agency
      Source consulted: 2026-09-21. This is a reference resource, not a claim that we conducted the studies or tested a product.
    3. Growth Hormone in Sport: What Athletes Should Know | USADA
      Source consulted: 2026-09-21. This is a reference resource, not a claim that we conducted the studies or tested a product.
    4. Deer Antler Velvet in Dietary Supplements
      Source consulted: 2026-09-21. This is a reference resource, not a claim that we conducted the studies or tested a product.
    5. Dietary Supplements: What You Need to Know - Consumer
      Source consulted: 2026-09-21. This is a reference resource, not a claim that we conducted the studies or tested a product.