I have been taking 600 mg of NAC daily as part of Life Extension Mix for years, long before my PD diagnosis. I Haven't noticed any benefit. Perhaps the dose is inadequate.

I have been taking 1200 mg NAC with 100mg Alpha lipoic acid for may be a couple of years. There is no way for me to tell that it is doing any thing for my PD which has been progressing steadily but I believe slowly since diagnosis about 6 years ago.
When my neuro asked me why to I take my supplements, I answered her : every body needs placebos.

"I don't know if it works but I dare not quit!"
For what it is worth, I started it two weeks ago and suspended my other supplements temporarily (enzymes and creatine). I am pleased thus far but it could be the others wearing off.

I take 500- 1000 mg. of NAC regularly (for 5 years). The brand I take, Jarrow, has this on it's label:
"NAC is a powerful antioxidant amino acid and a precursor in the body to the critical antioxidant glutathione.
Glutathione exerts a variety of protective effects, including detoxification and intracellular defense against oxidative stress."
My feeling is that all us PWP need as many antioxidants as possible- because of possible particular sensitivities to toxins and because of all the meds and their metabolites in our system. I think of it as taking out the garbage as often as possible.

1: Med Hypotheses. 2001 Apr;56(4):472-7.

Therapeutic potential of N-acetylcysteine in age-related mitochondrial
neurodegenerative diseases.

Banaclocha MM.

Department of Pathology, Hospital La Paz, Madrid, Spain. marbanaci@latinmail.com

Increasing lines of evidence suggest a key role for mitochondrial damage in
neurodegenerative diseases. Brain aging, Parkinson's disease, Alzheimer's
disease, Huntington's disease and Friedreich's ataxia have been associated with
several mitochondrial alterations including impaired oxidative phosphorylation.
Mitochondrial impairment can decrease cellular bioenergetic capacity, which will
then increase the generation of reactive oxygen species resulting in oxidative
damage and programmed cell death. This paper reviews the mechanisms of
N-acetylcysteine action at the cellular level, and the possible usefulness of
this antioxidant for the treatment of age-associated neurodegenerative diseases.
First, this thiol can act as a precursor for glutathione synthesis as well as a
stimulator of the cytosolic enzymes involved in glutathione regeneration.
Second, N-acetylcysteine can act by direct reaction between its reducing thiol
group and reactive oxygen species. Third, it has been shown that
N-acetylcysteine can prevent programmed cell death in cultured neuronal cells.
And finally, N-acetylcysteine also increases mitochondrial complex I and IV
specific activities both in vitro and in vivo in synaptic mitochondrial
preparations from aged mice. In view of the above, and because of the ease of
its administration and lack of toxicity in humans, the potential usefulness of
N-acetylcysteine in the treatment of age-associated mitochondrial
neurodegenerative diseases deserves investigation. Copyright 2001 Harcourt
Publishers Ltd.

Publication Types:
Review

PMID: 11339849 [PubMed - indexed for MEDLINE]

Left the house this morning without the NAC and had a crappy day with no other obvious explanation. I have been taking 600 mcg 3X per day. Has a little selenium and molybdenum mixed in as well. NOW brand.