N-acetyl cysteine (NAC) is generally recognized as one of the fastest ways to increase glutathione levels. Glutathione is needed to detoxify various drugs such as acetaminophen or paracetamol (Tylenol). Therefore, NAC is generally prescribed in cases of paracetamol overdose.

Oral bioavailability is 6-10%. Much of NAC taken orally is excreted. Excretion is also fairly rapid, about a 4 hour half-life. For these reasons, it is possible that the typical dose found in NAC supplements (500-800mg) is excessive. Two or three smaller doses of 250-300mg taken at regular intervals through out the day would probably make much more cystiene available for glutathione production.

One solution would be to buy NAC in the form of a tablet that can be easily broken into a two or three pieces. Then these can be swallowed individually through out the day. A good quality product at a reasonable price Source Naturals 600mg NAC tablets.

Long term use of NAC may cause problems, however. NAC presents a stronger set of side effects copared to the alternative cysteine donor, whey protein. Studies also suggest that long term use of NAC might increase the liklihood of developing pulmonary arterial hypertension. Whey protein powder is probably a better choice for long term management of glutathione metabolism even though it might be somewhat less convenient.

Taking an antioxidant that supports glutathione metabolism such as alpha lipoic acid is probably helpful.