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    L-Carnitine

    With meals

    L-Carnitine is a naturally occurring amino acid derivative synthesized from lysine and methionine, with the highest dietary concentrations found in red meat and dairy products. It plays a central role in cellular energy metabolism by shuttling long-chain fatty acids into the mitochondria where they are oxidized for fuel. It is available in several supplemental forms, with acetyl-L-carnitine (ALCAR) being the most bioavailable and widely studied.

    Andrew HubermanAndrew HubermanTakes it
    Research Evidence
    Supports cognitive function and neuroprotection via acetyl-L-carnitine form
    Limited
    May improve cardiovascular risk markers including CRP and cholesterol ratios
    Moderate
    Improves sperm motility, count, and overall male fertility markers
    Moderate
    Enhances exercise recovery and reduces markers of muscle damage
    Moderate
    Supports mitochondrial fatty acid oxidation and cellular energy production
    Strong
    Source: Examine.com

    Expert Evidence

    4 references from 1 expert

    Currently takes

    “I take L-carnitine every day. I've been kind of experimenting with that a little bit, which is not a psychedelic compound.”

    Unknown Title

    1:46:03
    Andrew Huberman

    4 references in 3 episodes from 2021–2023

    AI-generated summary

    Huberman takes L-carnitine daily and recommends acetyl-L-carnitine at 500mg–3g/day in divided doses, citing benefits for egg and sperm quality (1–3g/day for 30–60 days) as well as reductions in ammonia, C-reactive protein, and blood glucose. No cautions or side effects are discussed.

    2023
    Safety & Cautions

    Side Effects

    • Fishy body odor at higher doses
    • Nausea or stomach discomfort
    • Diarrhea
    • Restlessness or difficulty sleeping if taken late in the day
    L-Carnitine is generally well-tolerated at doses up to 2,000 mg per day. Individuals with thyroid conditions should consult a physician, as carnitine may interfere with thyroid hormone action, and those with a history of seizures should exercise caution with high doses.
    Pairs Well With
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    Price Comparison
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    NOW FoodsBest Value
    4.5
    •100 ct

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    $16.99 total

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