Over-the-counter supplements may contain

Over-the-counter supplements may contain a version of carnitine called acetyl-l-carnitine but beware that some have very little L-carnitine in them; be sure to buy from a reliable source. In Canada, L-carnitine is available by prescription and is called Carnitor. Prescription L-carnitine is very expensive and usually not covered by insurance plans for any of these indications. Check with your private insurer or provincial provider for more details.

The therapeutic dose for L-carnitine is somewhere between 500 and 3,000 mg daily. The dosage is not defined because it has not been studied enough or approved for these applications. Some people with HIV who have mitochondrial toxicity and/or peripheral neuropathy appear to benefit from 1,500 mg of acetyl-l-carnitine once or twice daily for many months. Carnitine supplements should be spread out over 3 daily doses to prevent side effects, most commonly diarrhea.

N-acetyl cysteine (NAC), a derivative of the amino acid L-cysteine, is a potent antioxidant that regenerates glutathione in the cell (see “Antioxidants and HIV,” this chapter). In this role, NAC protects liver cells by decreasing oxidation. Cysteine appears to decline in people with HIV who have low CD4+ cell counts and in those with wasting (see “Weight loss and wasting,” Chapter 6). NAC supplements may be able to replenish low glutathione and improve the antioxidant capacity of cells. Study doses have been as high as 2,000 mg per day, but this is expensive and may not be well tolerated. Side effects include nausea, vomiting, diarrhea and headache. The most beneficial dose is not certain, although a dose of 500 mg per day may offer some benefit with a reduced risk of toxicity.