Medicines & Supplements A to Z > L-Carnitine


Last updated on 16/07/2021.

Overview   |   Dosage   |    Side Effects   |   Precautions  |   Tips  |   Where To Buy  

GENERIC NAME: L-Carnitine, L-Carnitine

CHINESE NAME: 左旋肉鹼, 肉鹼, 卡尼丁

BRAND NAME(S) IN HONG KONG: Renilon 腎宜康, ProSure 保康速

DRUG CLASS: Supplements

SUB CLASS: Amino acid derivatives

USED FOR: Nutritional supplementation

What is L-Carnitine for?

L-carnitine is a substance similar to amino acid that is produced in the body. The body makes sufficient L-carnitine to meet its natural needs, however in some individuals who cannot make enough (due to genetic or medical reasons), L-carnitine is a conditionally essential nutrient and must be obtained from food or supplements. There is another form of carnitine called D-carnitine, which is not produced nor used by the body, hence L-Carnitine is more commonly seen in nutritional supplements.

L-carnitine plays a critical role in energy production as it helps the body metabolise fat into energy. It is often promoted as an aid for weight loss, to improve exercise performance, and to improve well-being. It is also important for heart and brain function, muscle movement, and many other body processes. L-carnitine can improve red blood cell counts during haemodialysis, therefore it may be supplemented in patients with serious kidney disease who are undergoing haemodialysis.

How to use it?

Healthy children and adults do not need to consume carnitine from food or supplements because the liver and kidney produce sufficient amounts from the essential amino acids Lysine and Methionine to meet daily needs. However, for people who cannot make enough L-carnitine on their own, they may take L-Carnitine supplements, which are commonly available as tablets or capsules. There are no established Dietary Reference Intakes (DRIs) for L-carnitine.

What are the side effects of L-Carnitine?

Taking more than 3 g of L-carnitine supplement daily may cause nausea and vomiting, abdominal cramps, diarrhea, and a “fishy” body odour.

Who should not take L-Carnitine?

– Patients on dialysis with reduced kidney function or kidney failure.
– Patients with a history of seizures.

Pharmacist Tips:

– It is always best to consult your doctor or pharmacist before starting any supplement, especially if you already take medication, have health concerns, or are pregnant.
– Animal products like meat, fish, poultry, and milk are rich sources of L-carnitine. Red meat usually contains higher L-carnitine content.

Common dosing schedule:
Please refer to specific product instructions.

Some common medications L-Carnitine may interact with:
– Thyroid replacement hormones, e.g. Levothyroxine

Please notify your doctor or pharmacist if you are taking the above medication, dosage adjustments might be needed.

Where to buy L-Carnitine in Hong Kong?

In Hong Kong, L-Carnitine is an over-the-counter medicine and can be purchased without a prescription from any retail outlet in Hong Kong. This includes grocery stores, convenience stores, medicine shops, and pharmacies. To find a pharmacy near you, refer to the list of pharmacies (“Authorized Sellers of Poisons”) from the Hong Kong Department of Health.

For more information about drug names and ingredients, you can visit Hong Kong’s Drug Office at

Need more information?

For detailed information about the use of L-Carnitine (supplement) in children, pregnancy and breastfeeding, and for questions about drug interactions, please check with your pharmacist or doctor.

Disclaimer: our goal is to provide you with the most relevant drug information and common dosage for Hong Kong. This information does not constitute medical advice. For specific treatment recommendations and advice, always discuss with your doctor or pharmacist, and follow the instructions included with your specific medicine.