What Is It Really?

NAC (N- acetylcysteine) is a derivative of the naturally occurring amino acid cysteine. In the United States, NAC is available by prescription as an aerosol drug (similar to aerosolized pentamidine) to treat bronchitis. NAC is also used in liquid form in very high doses to treat Tylenol overdoses. In Europe, NAC is very commonly used for bronchitis, and is produced in two oral forms.

The Theory Behind NAC

One reason PWAs take NAC is to try to pump up levels of glutathione (GSH). GSH is a vital protein that cells need to function. Many studies have documented low GSH in people with HIV. Dr. Luc Montagnier's work with CD4 cells from PWAs suggests that even cells without HIV can grow weak and die, but with added GSH can regain their vigor. This is where NAC comes in. NAC is broken down by the body into cysteine. Researchers have also noted that low levels of cysteine in PWAs. The body uses cysteine to replace glutathione. Taking NAC may be a way to add cysteine, so that your body can replenish depleted GSH levels. It is still unclear whether NAC is converted to GSH in PWAs.

More Theory Behind Taking NAC

Whether or not NAC is converted to GSH, it might help protect the body from the effects of excess TNF-alpha (tumor necrosis factor). TNF is a naturally occurring protein in your body. It's often elevated in people with HIV and may be a part of HIV disease. It can turn on latent HIV, and increase HIV reproduction. It can cause a generalized inflammatory response that may be critical to AIDS-related weight loss. Both GSH and NAC interfere with TNF in the test tube.

NAC and GSH are also anti-oxidants -substances that mop up free radicals, volatile particles produced naturally in the body, especially when you have an infection. Too many free radicals can cause inflammation and damage organs; and like TNF, may turn on and speed the spread of HIV. How much these free radicals contribute to HIV disease is unclear.

There are reports that taking NAC with dapsone reduces some of that drug's toxicity without reducing its effectiveness. There are ongoing studies in Canada to see whether NAC may decrease PWAs' allergic reactions to Bactrim/Septra.

NAC Studies in PWAs

Studies of NAC seem to have raised more questions than they've answered. An NIH study was disappointing: after 12 weeks of taking up to 9600 mg a day, NAC had no effect on CD4 cell counts or p24 (a sloppy marker of HIV activity). However, PWAs in the study had regular GSH levels, so NAC shouldn't have done much for them anyway. More research is needed to see what NAC can do for PWAs who have low GSH levels.

This NIH study created a storm of controversy. The researchers reported that NAC was very poorly absorbed - it did not get into the blood, and that people in the study had no change in their intracellular GSH levels. Other researchers protested that the NIH didn't follow the proper procedures for measuring NAC or GSH levels.

A later study in HIV positive people with low GSH reported increased intracellular GSH 4 hours after taking a single dose of NAC (figured as @1800 mg if you weigh 130 pounds). A small study at Stanford also reported that 7 PWAs taking 1000-2000 mg for up to 12 weeks had an immediate increase in intracellular GSH. There's an on-going study at Stanford using 8000 mg/day to sort this out.

2 New Studies (summer '94)

15 people with HIV in Brazil took either 400 mg iv twice a day, or 600 mg capsules twice a day. The 8 people on iv NAC fared best, moving from an average of 256 CD4 cells to 501. The 7 people taking the oral dose went from 403 CD4s to 563, and 1449 CD8s to 2376.

Much more interesting was a one-year, three arm Mexican study of 300 people with HIV. The study compared AZT (500 mg) to AZT/ddC and AZT/ddC/NAC (NAC-1500 mg/day). There were significant differences in opportunistic infections and CD4 counts between the AZT-only group and the other two groups. AZT only: 62% developed new OIs, and their CD4's slipped from an average of 247 to 181 over the course of the year. AZT/ddC: 32% got OIs and their CD4s rose steadily from 175 to 294. AZT/ddC/NAC: 23% developed OIs and their CD4 cells went from 148 to 356. The difference between taking AZT/ddC or the NAC combo was not statistically significant, but adding NAC seemed to show a trend toward greater response.


No one knows what the best dose of NAC is. Most PWAs in America take between 1200-1800 mg a day based upon test tube data, and the advice of American researchers who have been studying NAC in HIV disease for years. This may not be the best dose in the body. A German researcher who has also been working with PWAs and NAC for several years maintains that people should take 400-600 mg three times a week, preferably two hours after exercise (the less is more theory). Who's right? Only large clinical trials will tell.

Side Effects and Toxicity

NAC has been used safely at doses up to 11,000 mg a day, but side effects can occur. A few clients from the Health Group have also reported some stomach upset and diarrhea while on NAC. One patient in the NIH study had an anaphylactoid reaction (a severe bronchial spasm) in the highest IV dose group. Anemia, thrombocytopenia, nausea and weight loss were also seen in this study, but these effects were not necessarily caused by NAC.

No drug interactions were reported from the NIH study. However, the Martindale Extra Pharmacopoeia reports that some antibiotics, including amphotericin, ampicillin, erythromycin and tetracycline may be incompatible or inactivated when mixed with NAC.

PWAs with a history of ulcers should perhaps avoid NAC, since it can reduce mucous that they need to protect their stomachs.

NAC is a chelating agent, and may purge minerals from your body. Nutritionists recommend keeping track of minerals and taking some supplements if necessary.

What We Carry

The Health Group imports pharmaceutical grade NAC from Switzerland and Germany. In the US, several companies make NAC and sell it through health food stores. Is there a difference between imported NAC and health food store NAC? We don't know. Health food store NAC can be cheaper. Health food products are manufactured with no FDA monitoring to guarantee the quality. We paid an independent laboratory to test one brand of health store NAC. It was fine. But this tells us nothing about the product's shelf-life, or even other jars of the same product.

Pharmaceutical grade NAC is guaranteed to have a standard amount of NAC in each tablet. It is also packaged in air tight wrapping (the capsules) or with a dessicant in the lid (effervescents) so that the NAC will not degrade once it is exposed to air. The third difference is that pharmaceutical grade NAC also contains a mild buffer, so it's gentler on the digestive system.

We carry two kind of NAC: 800 mg effervescent tablets and 200 mg capsules. The effervescent form is cheaper per mg.

  • Effervescent NAC comes as fizzy tablets which you dissolve in 8 oz. of water, like alka seltzer. The tablets are made by Elan SA in Switzerland, where they are approved for bronchitis. This brand of NAC comes in tubes of 10 x 800 mg tablets. Each tube costs $8.50. This NAC contains Nutrasweet (aspartame).
  • Capsules: Fluimucil Kapseln are regular capsules, swallowed like any other pill. The capsules are made by Inpharzam, a subsidiary of the Zambon Group, in Germany. The capsules (200 mg each) come 15 to a box for $14.00 per box and have no sweetener.