Enhanced fat metabolism and oxidation
Significantly improves fat burning and fatty acid oxidation for energy
L-Carnitine
Essential amino acid-like compound that transports fatty acids into mitochondria for energy production, supporting fat metabolism, exercise performance, and metabolic health
Scientific nameL-Carnitine
FormulaC7H15NO3
Molecular weight161.2 g/mol
CAS541-15-1
85
absorption score
8
safety / 10
30
USD per month
5
documented interactions
Check it against something
L-Carnitine with:
- Amylase
- Ashwagandha
- Avocado Oil
- BCAA (Branched-Chain Amino Acids)
- Beetroot Powder
- Beta-Alanine
- Bifidobacterium lactis
- Bifidobacterium longum
- Bovine Collagen
- Caffeine
- Calcium
- Calcium Bone Formula
- Calcium Carbonate
- Casein Protein
- Chicken Collagen
- Choline (Bitartrate)
- Chondroitin Sulfate
- Coconut Oil
- Coenzyme Q10 (CoQ10)
- Collagen Peptides
- Comprehensive Immune Support Complex
- Comprehensive Multivitamin-Mineral Complex
- Creatine HCL
- Creatine Monohydrate
- D-Mannose
- DHA
- Electrolyte Blend
- EPA
- Fish Oil (EPA/DHA)
- Folate (5-MTHF)
- Ginger
- Iron Fumarate
- Iron Sulfate
- Joint Mobility Formula
- Keratin
- Krill Oil
- L-Citrulline
- Lactase
- Lactobacillus acidophilus
- Lactobacillus rhamnosus
- Lipase
- Magnesium Citrate
- Magnesium Glycinate
- Magnesium Oxide
- Marine Collagen
- Melatonin
- Modafinil
- Olive Oil Extract
- Omega-3 + Curcumin + Vitamin D Triple Anti-Inflammatory Formula
- Papain
- Protease
- Saccharomyces boulardii
- Turmeric
- Vitamin B12 (Cyanocobalamin)
- Vitamin B12 (Methylcobalamin)
- Vitamin C (Ascorbic Acid)
- Vitamin C (Sodium Ascorbate)
- Vitamin D3
- Whey Protein
- Zinc Gluconate
Nothing found
78
out of 100
Works better together
Compatible. Timing differs, so follow each supplement's own window.
What it does
mechanism and evidence for each claimImproved exercise performance and recovery
Enhances exercise capacity, endurance, and post-exercise recovery
Metabolic rate enhancement
Boosts metabolic rate and energy expenditure
Weight management support
Supports healthy weight loss and body composition improvement
Cardiovascular and heart health
Supports heart health and cardiovascular function
Others take these for the same thing
Same goal, different mechanism — check any of them against this one
Ashwagandha
Stress management & energy
300-600mg
A
75%
Vitamin B12 (Cyanocobalamin)
Energy & nerve support
250-1000 mcg
A
70%
Coenzyme Q10 (CoQ10)
Heart health & cellular energy
100-200mg
A
10%
Phosphorus
Bone health & energy metabolism
700-1250mg
A
80%
Vitamin B3 (Niacinamide)
Energy & skin health (no flush)
100-1000 mg
A
88%
Berberine for Advanced Glucose Control and Metabolic Support
Blood sugar control & metabolic support
1500mg daily (500mg x3)
A
60%
Every pair we checked
12 combinations scored by the engine
L-Carnitine + Creatine Monohydrate
No documented interaction either way
No known interaction
70
L-Carnitine + Vitamin D3
No documented interaction either way
No known interaction
70
L-Carnitine + Calcium Carbonate
No documented interaction either way
No known interaction
70
L-Carnitine + Whey Protein
No documented interaction either way
No known interaction
70
L-Carnitine + Lactase
No documented interaction either way
No known interaction
70
L-Carnitine + Bovine Collagen
No documented interaction either way
No known interaction
70
L-Carnitine + DHA
No documented interaction either way
No known interaction
70
L-Carnitine + Turmeric
No documented interaction either way
No known interaction
70
L-Carnitine + Fish Oil (EPA/DHA)
No documented interaction either way
No known interaction
70
L-Carnitine + Coenzyme Q10 (CoQ10)
Enhanced mitochondrial energy production and cardiovascular benefits
Works better together
78
L-Carnitine + Alpha-Lipoic Acid (ALA)
Enhanced fat metabolism and antioxidant protection
Works better together
78
L-Carnitine + Caffeine
Enhanced fat burning and exercise performance
Works better together
82
Dosage
Daily1-3g
Fat metabolism2-3g daily
Exercise performance2-3g daily pre-workout
Weight management2-3g daily with meals
Cardiovascular health1-2g daily
When to expect it
First Effects1-4 weeks for initial energy and exercise performance improvements
Peak Benefits6-12 weeks for sustained metabolic and fat burning benefits
Deficiency DevelopmentRare but can develop with poor diet or certain conditions
Toxicity OnsetVery rare, mainly GI upset with excessive doses
How to measure it
MarkerSerum carnitine levels, fatty acid oxidation markers, metabolic panel
OptimalAdequate carnitine levels, improved fat oxidation markers
Deficient belowLow carnitine levels, poor fat metabolism markers
FrequencyEvery 6-12 months for metabolic health assessment
What people actually reported to the FDA
CAERS, 110 reports naming it as the suspectMost reported effects
Named as the suspect
110 reports
of 142 that mention it at all
Serious outcome
83%
hospitalisation, emergency room or worse
Other Serious or Important Medical Event69
Hospitalization42
Visited Emergency Room36
Reports are voluntary and unverified — they record what someone experienced while taking something, not what the compound caused. Counts skew towards products people take a lot of, and a serious outcome is more likely to be reported than a mild one, so these are not rates. How we filter them →
What actually reaches you
The label counts the carrier, your body does not
Absorption
Very high 85 of 100 · best absorbed form of this compound
Delivered daily
1700 mg
Cost per 100 mg delivered
$0.06 comparative — uses the absorption score, not a measured percentage
Works better with
+
Coenzyme Q10
Enhanced mitochondrial energy production and cardiovascular benefits
Both support mitochondrial function and energy metabolism · level B
+
Alpha Lipoic Acid
Enhanced fat metabolism and antioxidant protection
Both support mitochondrial function and glucose metabolism · level B
+
Caffeine
Enhanced fat burning and exercise performance
Synergistic effects on fat oxidation and energy production · level AWhat not to take with L-Carnitine
!
High Carbohydrate Meals
High carbs may reduce fat oxidation benefits
Glucose availability reduces fatty acid oxidation · moderate significance
!
Valproic Acid
Anticonvulsant may deplete carnitine levels
Drug interferes with carnitine metabolism · high significanceMedication interactions
Discuss these with a pharmacist before combiningMay enhance anticoagulant effects
What to do: Monitor clotting times if on blood thinners
May enhance thyroid hormone effects
What to do: Monitor thyroid function
Available forms
L-Carnitine L-Tartrate (LCLT): Proven fat burning, Exercise performance, Heart health, Well researched
Food sources
Red meat (lamb, beef)
80-120mg per 100g · 75
Fish and seafood
20-25mg per 100g · 70
Dairy products
2-8mg per 100g · 65
L-carnitine supplements
500-1000mg per dose · 85
Too little
- L-carnitine deficiency symptoms:
- Poor fat metabolism and energy production
- Reduced exercise capacity and endurance
- Muscle weakness and fatigue
- Poor recovery from exercise
- Impaired heart function in severe cases
- Difficulty losing weight despite diet and exercise
Too much
- Generally safe with minimal side effects:
- Gastrointestinal upset with high doses
- Fishy body odor in susceptible individuals
- Sleep disturbances if taken late in day
- Generally well tolerated by most people
Who benefits most
weight-loss-fat-burning
Enhanced fat metabolism and weight management support
2-3g daily divided doses
athletic-performance-enhancement
Improved exercise performance, endurance, and recovery
2-3g daily, 30-60 minutes before exercise
metabolic-health-optimization
Enhanced metabolic rate and energy production
1-2g daily
cardiovascular-health-support
Heart health and cardiovascular function enhancement
1-2g daily
aging-metabolic-support
Age-related metabolic decline support and energy enhancement
1-2g dailyWhere to buy it
Look for L-Carnitine at 1-3g per serving. The form that matters here is L-Carnitine L-Tartrate (LCLT).
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What else affects it
Beyond other supplements
!
High carbohydrate meals
High carbs may reduce fat oxidation benefits
Glucose availability reduces fatty acid oxidationHow it works
- Transports long-chain fatty acids across mitochondrial membrane for beta-oxidation
- Essential cofactor for fatty acid metabolism and energy production
- Reduces accumulation of toxic fatty acid metabolites in cells
- Enhances mitochondrial efficiency and energy output
- Supports cardiac muscle energy metabolism and function
- Reduces exercise-induced oxidative stress and muscle damage
Key findings
what the evidence supports- Extensive evidence for fat metabolism and exercise performance benefits
- Strong research on cardiovascular health and heart function
- Good evidence for weight management when combined with exercise
- Excellent safety profile with proper dosing
Sources: NIH Examine.com · data reviewed 2026-08-02
Compiled by Denis, who maintains this database and holds no medical qualification — every figure here is sourced or derived, never asserted. How we calculate it →
Common questions
What are the benefits of L-Carnitine?
Documented effects: Enhanced fat metabolism and oxidation; Improved exercise performance and recovery; Metabolic rate enhancement; Weight management support. Significantly improves fat burning and fatty acid oxidation for energy
How much L-Carnitine should you take per day?
The common daily range is 1-3g. By goal — fat metabolism: 2-3g daily; exercise performance: 2-3g daily pre-workout; weight management: 2-3g daily with meals; cardiovascular health: 1-2g daily.
When is the best time to take L-Carnitine?
Pre workout or meals. First effects are typically reported within 1-4 weeks for initial energy and exercise performance improvements.
What are the side effects of L-Carnitine?
At excessive doses: Generally safe with minimal side effects:, Gastrointestinal upset with high doses, Fishy body odor in susceptible individuals, Sleep disturbances if taken late in day, Generally well tolerated by most people. Safety rating at normal doses is 8 out of 10.
What should you not take with L-Carnitine?
Separate it from High Carbohydrate Meals, Valproic Acid by two to four hours. High carbs may reduce fat oxidation benefits
Does L-Carnitine interact with medications?
Documented interactions with anticoagulants, thyroid-medications. Discuss these with a pharmacist before combining.
How do you know if you need L-Carnitine?
The marker is Serum carnitine levels, fatty acid oxidation markers, metabolic panel, optimal range Adequate carnitine levels, improved fat oxidation markers. Common deficiency signs: L-carnitine deficiency symptoms:, Poor fat metabolism and energy production, Reduced exercise capacity and endurance, Muscle weakness and fatigue.