Browse/Amino Acid
Amino Acid

L-Carnitine L-Tartrate (LCLT)

01 / OVERVIEW

What this compound does

WHAT IT DOES

L-Carnitine L-Tartrate is a form of L-carnitine that helps your body turn fat into energy. It gives your muscles more fuel during exercise and helps clear waste products that make you feel tired. It also helps muscles recover faster after a workout and may support heart health and brain function.

KEY BENEFITS
Boosts energy during exercise
Reduces muscle soreness after workouts
Improves recovery between exercise sessions
Supports fat burning for fuel
May improve mental focus and reduce fatigue
BEST FOR
  • • Athletes and active people wanting better endurance
  • • People recovering from injuries or muscle soreness
  • • Adults looking to support heart health
  • • Those with low energy levels or chronic fatigue
WHAT TO EXPECT

Users may notice improved energy during workouts and less soreness within a week. Benefits for overall energy and recovery typically become noticeable after 2-4 weeks of consistent use.

WHO SHOULD AVOID THIS
  • • People with a history of seizures
  • • Those on blood thinning medication (theoretical caution)
  • • Pregnant or breastfeeding women (insufficient safety data)
  • • Individuals with kidney disease (especially chronic kidney disease)
MYTHS & FACTS
Myth: L-carnitine causes heart disease because it is converted to TMAO.
Fact: Although dietary L-carnitine can produce TMAO, human studies show that L-carnitine supplementation does not increase cardiovascular risk in healthy individuals and may even benefit heart health. LCLT is well-absorbed and less prone to gut bacterial conversion than red meat sources.
Myth: L-carnitine burns fat without exercise.
Fact: L-carnitine helps the body use fat for fuel, but it is not a standalone weight loss supplement. It works best when combined with regular exercise and a balanced diet.
Myth: All carnitine forms are the same.
Fact: LCLT has higher bioavailability and better muscle uptake than L-carnitine HCl, and it causes less gastrointestinal discomfort. Acetyl-L-carnitine (ALCAR) is better for brain health, while LCLT is optimal for muscle performance.
At a glance
Typical dose
2
Loading: 2 g/day × 7 days (optional for faster saturation)
Evidence
—
Studies indexed7
How it's made

Production details below.

03 / DOSAGE

How much, when

MAINTENANCE

2

LOADING PROTOCOL

2 g/day × 7 days (optional for faster saturation)

Divide daily dose into 2-3 smaller doses taken with meals; avoid evening dosing to prevent insomnia; may be taken pre- or post-workout

TIMING

L-Carnitine L-Tartrate (LCLT) — Any dose

Take with food (high-fat meal)

02 / EVIDENCE

Peer-reviewed studies

  • PMID: 12701834

    Muscle soreness reduction

    LCLT supplementation (2 g/day for 3 weeks) reduced muscle soreness biomarkers and subjective soreness after resistance exercise in 21 healthy men (placebo-controlled crossover).

    A
  • PMID: 30090990

    Improved exercise recovery

    A meta-analysis of 9 RCTs (n=273) found L-carnitine (1-3 g/day) significantly improved recovery markers and reduced muscle damage after exercise (SMD -0.79).

    A
  • PMID: 11964843

    Enhanced fat oxidation

    LCLT (2 g/day for 6 weeks) increased fat oxidation during exercise by 55% in 18 moderately active adults (randomized, double-blind, placebo-controlled).

    B
  • PMID: 12812973

    Reduced fatigue in aging

    L-carnitine (2 g/day for 30 days) reduced physical and mental fatigue scores in 66 elderly subjects (RCT, placebo-controlled).

    B
  • PMID: 16896063

    Androgen receptor upregulation

    LCLT (2 g/day for 3 weeks) increased androgen receptor content in skeletal muscle by 17% in young men undergoing resistance training (RCT).

    B
  • PMID: 25735323

    Improved endurance performance

    L-carnitine supplementation (2 g/day for 24 weeks) increased maximal oxygen uptake (VO2max) by 5% in 20 amateur athletes (double-blind RCT).

    B
  • PMID: 15990754

    Lactate buffering

    LCLT (2 g/day for 2 weeks) reduced blood lactate concentration during supramaximal exercise by 12% in trained cyclists (placebo-controlled crossover).

    B
  • PMID 34896904 · 2022RCT

    Probiotic supplement attenuates chemotherapy-related cognitive impairment in patients with breast cancer: a randomised, double-blind, and placebo-controlled trial

    B
  • PMID 30122200 · 2018RCT

    Daily oral supplementation with collagen peptides combined with vitamins and other bioactive compounds improves skin elasticity and has a beneficial effect on joint and general wellbeing

    B
  • PMID 9627906 · 1998Narrative Review

    The role of carnitine and carnitine supplementation during exercise in man and in individuals with special needs

    B
  • PMID 17309390 · 2007Narrative Review

    Algorithm for complementary and alternative medicine practice and research in type 2 diabetes

    B
04 / INTERACTIONS

Medicine interactions

  • Thyroid Hormone Replacement (Levothyroxine)· thyroid_med

    L-carnitine may inhibit thyroid hormone entry into cells, potentially reducing effectiveness of thyroid medication.

    → Monitor thyroid function tests; separate doses by at least 4 hours if using LCLT.

    MODERATE

  • Warfarin· blood_thinner

    L-carnitine may theoretically enhance the anticoagulant effect of warfarin by interfering with vitamin K metabolism.

    → Monitor INR closely when starting or stopping LCLT. Adjust warfarin dose as needed under medical supervision.

    MODERATE

  • Valproic Acid· anticonvulsant

    Valproic acid can deplete carnitine, and L-carnitine may reduce valproate efficacy or increase toxicity.

    → Use LCLT only under medical guidance; monitor valproate levels and liver function.

    MODERATE

  • Chemotherapy (Doxorubicin)· chemotherapy

    L-carnitine may reduce doxorubicin-induced cardiotoxicity, but could potentially interfere with efficacy.

    → Consult oncologist before use; LCLT is often given to reduce chemotherapy side effects in clinical settings.

    LOW

This page is a reference summary, not a prescription. Consult a clinician before starting, stopping, or combining supplements — especially if you take medication or have a medical condition.