L-carnitine: carnitine in endurance conversations
L-carnitine is mentioned by Yale Medicine as a supplement studied in men's health contexts and discussed in relation to energy metabolism and exercise support. That is why it keeps appearing in performance-oriented formulas rather than general multivitamins.
It is an amino-acid derivative, not a botanical, and it is rarely the only active ingredient in a product. If your week includes regular training, carnitine is worth recognising on a label. If it does not, it is still a legitimate ingredient to understand, just less relevant to your routine.
Where to look for it
Next to other energy and endurance ingredients, not alongside the vitamin-only base.