L-Carnitine
Amino Acid Derivative | Fatty Acid Transporter
L-Carnitine is an amino acid derivative naturally produced in the body and essential for transporting long-chain fatty acids into mitochondria for energy production. Injectable forms bypass digestive absorption limitations of oral supplements.
Mechanism of Action
Acts as a carrier molecule, shuttling long-chain fatty acids across the inner mitochondrial membrane via the carnitine palmitoyltransferase (CPT) system. This is the rate-limiting step in fatty acid oxidation for energy production.
Key Benefits
- Enhanced fatty acid transport to mitochondria
- Improved energy production from fats
- Better bioavailability than oral forms
- Support for exercise recovery
- Potential cognitive benefits
Metabolic
- Fatty Acid Oxidation
Primary function transporting fatty acids into mitochondria for beta-oxidation.
- Energy Production
Supports ATP generation from fat metabolism, particularly during exercise.
- Weight Management
May enhance fat utilization when combined with exercise and caloric deficit.
Performance
- Exercise Recovery
May reduce muscle damage markers and improve recovery post-exercise.
- Endurance Support
Enhances fat utilization during prolonged exercise, potentially sparing glycogen.
Clinical Uses
- Carnitine Deficiency
FDA-approved treatment for primary and secondary carnitine deficiency.
- Dialysis Support
Used in patients on hemodialysis who develop carnitine depletion.
Subcutaneous or intramuscular injection provides superior bioavailability compared to oral supplementation, which is limited to ~15-20% absorption.
| Goal | Dose | Frequency | Route |
|---|---|---|---|
| Standard Protocol | 50-100mg | Daily | SubQ |
| Advanced Protocol | 100-200mg | Daily | SubQ or IM |
| Pre-Workout | 100-200mg | 30-60 min before exercise | SubQ |
Reconstitution Instructions
- L-Carnitine lyophilized powder (typically 200mg vial)
- Bacteriostatic water (2.0mL recommended)
- Insulin syringes (29-31 gauge)
- Alcohol swabs
- 1 Allow vial to reach room temperature
- 2 Clean rubber stopper with alcohol swab
- 3 Add 2.0mL bacteriostatic water for 100mg/mL concentration
- 4 Inject slowly along vial wall
- 5 Gently swirl to dissolve; never shake
- 6 Label with date and store refrigerated at 2-8°C
- 7 Use within 2-4 weeks of reconstitution
L-Carnitine may affect thyroid hormone action. Those on thyroid medication should monitor levels.
May enhance effects of warfarin and similar medications.
Injectable form provides rapid absorption within 30-60 minutes
Potential improvements in energy and exercise capacity
Cumulative benefits on fat metabolism and recovery
Full metabolic optimization when combined with exercise
Common Side Effects
- Injection site reactions
- Mild nausea
- Body odor (fishy smell at high doses)
Stop Signs - Discontinue if:
- Allergic reactions (rare)
- Severe gastrointestinal distress
- Unusual muscle weakness
Contraindications
- Seizure disorders (may lower seizure threshold)
- Hypothyroidism (may affect thyroid function)
- Allergy to carnitine products
Good Signs
- White crystalline powder
- Clear, colorless solution after reconstitution
- Certificate of Analysis with purity testing
Warning Signs
- Should dissolve completely without residue
Bad Signs
- Discolored powder
- Cloudy or particulate solution
- Strong unusual odor
- L-Carnitine Supplementation and Exercise(2018)
Meta-analysis showing modest benefits of L-carnitine on exercise performance and recovery markers.
- Carnitine Metabolism and Function(2012)
Comprehensive review of carnitine's role in fatty acid transport and energy metabolism.
Disclaimer
This information is for educational and research purposes only. Consult a healthcare professional before use.