L-carnitine

What Does L-Carnitine Do?

L-carnitine is a naturally occurring amino acid derivative that plays a crucial role in energy production by transporting fatty acids into your cells' mitochondria. In a pre-workout context, it helps you tap into fat stores for fuel, preserving glycogen and extending endurance during high-intensity training.

• Enhanced Fat Oxidation: By shuttling long-chain fatty acids into the mitochondria, L-carnitine helps the body burn fat more efficiently for energy during aerobic exercise.
• Glycogen Sparing: By increasing fat utilization, your body relies less on stored muscle glycogen, which can delay the onset of fatigue during long training sessions.
• Improved Recovery: Research suggests L-carnitine can reduce muscle damage and markers of metabolic stress following intense resistance training.
• Androgen Receptor Density: Some studies indicate that L-carnitine L-tartrate may increase the density of androgen receptors in muscle cells, potentially enhancing the body's response to hormonal signals.

Clinical vs. Gym Bro Dosing

Key Insight: L-carnitine is most effective when insulin is present. To maximize muscle carnitine uptake, consider taking it with a small amount of carbohydrates or alongside your pre-workout meal rather than on a completely empty stomach.

Side Effects & Warnings

• Digestive Upset: High doses (over 3g) can cause nausea, abdominal cramps, or diarrhea in sensitive individuals.
• Fishy Body Odor: A rare side effect where the breakdown of carnitine produces trimethylamine, resulting in a distinct odor in sweat or urine.
• Restlessness: While not a stimulant, the increase in energy metabolism can make some users feel overly alert if taken too late in the evening.

Tip: If you experience stomach issues, try switching to L-Carnitine L-Tartrate or Acetyl-L-Carnitine (ALCAR), which are often better tolerated and have higher bioavailability than base L-carnitine.