L-carnitine (acetyl-l-carnitine) is an amino acid which plays an important role in fat burning. It acts rather like a juggernaut by transporting fatty acids into your cells’ energy-producing factories (mitochondria) so you burn fat more efficiently. Essentially, the more l-carnitine that’s available, the more fat you can burn, especially during exercise. This makes l-carnitine especially popular for both weight loss and for athletes.
By mobilising fat stores and boosting energy production, L-carnitine can boost weight loss and improve the appearance of cellulite, as well as lowering cholesterol and triglyceride levels. It also stimulates secretion of gastric and pancreatic juices to aid general digestion.
As a bonus, research also suggests that l-carnitine can improve energy levels, fatigue, memory, and even slow the ageing process. While we can’t make any promises, it does seem that l-carnitine is a useful weight loss aid.
How effective is l-carnitine for weight loss?
The results from 9 studies, involving 911 overweight people, confirmed that those who took l-carnitine lost significantly more weight compared with the control group. On average, taking l-carnitine results in an additional weight loss of 1.33 kg, and an additional decrease in body mass index (BMI) of 0.47 kg/m2.
When 60 overweight women with polycystic ovary syndrome (PCOS) took either 250 mg l-carnitine supplements or placebo for 12 weeks, those taking l-carnitine lost 2·7kg more than those on placebo, BMI reduced by 1·1kg/m2 more, and they lost 2cm more around the weiist and 2.5cm more around their hips than those taking placebo.
Where to get l-carnitine
L-carnitine is classed as a non-essential amino acid, as small amounts are made in the liver. L-carnitine is also found in red meat, offal, dairy products, avocado and fermented soybean products such as tempeh. However, some experts believe that people who are overweight may not make or use l-carnitine as efficiently as normal, and that taking additional supplements could be the key to kick-starting your weight loss process.
A typical dose is 250 mg to 2g daily. L-Carnitine, alpha-lipoic acid, and coenzyme Q10 work synergistically and are often taken together.
L-carnitine side effects
A risk assessemtne for l-carnitine concluded there was strong evidence for safety at intakes of up to 2,000mg (2 grams) per day. Some people notice an increased body odour and loose bowels at very high doses (over 4g daily).