NAC (N-acetylcysteine)

Health Tips / NAC (N-acetylcysteine)

What Is It?

Produced by the body, N-acetylcysteine (commonly called NAC) is a form of the amino acid cysteine. Because it enhances the production of the Enzyme glutathione, one of the body’s powerhouse antioxidants, NAC can both stave off disease and play an important role in boosting the immune system. Studies have shown that glutathione levels are often reduced in people with certain conditions related to the immune system.

For more than three decades, NAC has been used as a mucolytic (“Mucus dissolving”) agent to help break up the thick mucus often present in people suffering from chronic respiratory ailments. When administered intravenously, NAC has also proved invaluable in the treatment of acetaminophen overdose; it appears to protect the liver from this potentially toxic substance. Now widely available in supplement form, NAC is currently being recommended for preventing and treating a wide variety of ailments that may respond to its Antioxidant properties.

Health Benefits

Supplemental antioxidants–NAC is one of many– are believed to protect the body’s cells from altered oxygen molecules called Free radicals. Damage from free radicals is thought to be a signficant factor in such degenerative conditions as cancer and heart disease. Of course, factors other than oxidative damage, such as life style factors and genetic susceptibility, play strong roles in disease development as well. The hope is that by reducing susceptibility to free radical damage, a person may further lower susceptibility to a variety of chronic medical conditions. Incidentally, it is by means of its antioxidant actions that NAC helps the liver eliminate potentially dangerous environmental and biological toxins from the body.

Specifically, NAC may help to:

  • Reduce congestion related to sinusitis, bronchitis, asthma, and other respiratory diseases. Conventional physicians routinely use NAC to dilute thick mucus, making it much easier to cough up or drain from the nasal passages and other congested areas. It’s often used to ease congestion in people with pneumonia and other chronic respiratory diseases. It has even been shown to reduce mucus secretions in people who smoke or who are regularly exposed to secondhand smoke. Outcomes have not been as promising in the treatment of chronic obstructive pulmonary disease (COPD). Twenty-five patients administered NAC in addition to conventional medical treatments for COPD, did not show improved measure of breathing or earlier hospital release. Ask your doctor to assess whether adding NAC to your diet may be helpful in your condition.
  • Prevent damage from diabetic nephropathy. The end products of lipid oxidation cause nerve and kidney damage. Treatment with strong antioxidants such as NAC may help prevent or reduce the severity of diabetic nephropathy.
  • Treat HIV-infected individuals. Some studies have shown that NAC interferes with the replication of certain viruses, including the HIV (human immunodeficiency virus) responsible for causing AIDS. Just what this means for HIV-infected individuals remains unclear, however. Because NAC can boost glutathione production, it supports the proper functioning of immune-system components such as T cells, B cells, and phagocytes, all of which are important for maintaining the body’s defenses and potentially protecting against AIDs-related illnesses such as pneumonia.
  • Lessen flu symptoms. By thinning mucus and weakening the flu virus, supplemental NAC could potentially lessen the severity and duration of the flu. In a study of 262 elderly participants only 25% of the NAC treated group developed the flu symptoms compared to 79% of the group receiving Placebo.
  • Prevent heart disease. In some studies, NAC appears to significantly lower levels of Homocysteine and possibly lipoprotein(a), substances associated with an increased risk of heart disease. As an antioxidant, it also helps prevent the damaging oxidation–and thereby the precipitation–of LDL (“bad”) cholesterol from the material that lines blood vessels. More research in this area is needed, however.
  • Delay age-related cataracts and macular degeneration. Both of these conditions have been associated with damage from oxygen free radicals. By boosting antioxidant activity in the eye’s lens and macula, NAC may have a role to play in preventing cataracts (which cause the lens to become cloudy) and macular degeneration (which can result in blindness as this area of the retina deteriorates).
  • Counter environmental toxins. NAC-supported glutathione interacts with the dangerous byproducts of many toxic substances, promoting their excretion through the liver. These substances include carbon tetrachloride, chloroform, and carbon monoxide; alcohol; such heavy metals as mercury, chromium, and boron; and the microorganisms aflatoxin and Eschicheria coli.
  • Lessen the risk of cancer. By helping to rid the body of environmental toxins and by fighting free radicals, NAC, at least theoretically, may have a role to play in preventing cancer. NAC might also slow the growth of cancerous tissues in these ways. Clinical trials are underway to explore this possibility. Interestingly, one study did find that NAC reduced adverse reactions to chemotherapy.
  • Slow the progression of multiple sclerosis. One theory regarding the cause of this degenerative condition attributes it to free-radical damage caused by low levels of glutathione. If this is true, NAC’s antioxidant actions may be of help in protecting nerve cells from such damage. More research on NAC’s effect on this disease is clearly needed.
  • Affect the course of Parkinson’s disease. Parkinson’s disease is often marked by reduced quantities of glutathione in the brain. In theory, boosting glutathione with NAC supplements could slow loss of function in Parkinson’s. NAC’s antioxidant actions might also help by minimizing age-related deterioration of the nervous system.

Note: Antioxidants in general and NAC in particular have been considered useful for a number of other disorders. For information on these additional ailments, see our Dosage Recommendations Chart for NAC.


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Dosage Information

Special tips:

  • Regular supplementation with NAC will increase the urinary excretion of copper, a Mineral. So if you’re using NAC for an extended period of time, it’s probably wise to add both copper (2 mg a day) and zinc (30 mg a day) to your treatment regimen.
  • If you use NAC for more than a month, add a mixed amino acid complex to your treatment regimen to ensure that you are getting adequate, balanced amounts of all the Amino acids.
  • NAC is also available as an intravenous solution and inhalant, but by prescription only. Follow doctor recommendations regarding dosage and administration of these forms.
  • For the majority of ailments mentioned: Take 500 mg three times a day.
  • For bronchitis: For acute bronchitis, take 500 mg three times a day between meals. For chronic bronchitis, take 250 mg three times a day between meals.
  • For sinusitis: Take 500 mg twice a day between meals.
  • For multiple sclerosis: Take 500 mg three times a day every other day between meals; alternate with 30 mg zinc and 2 mg copper.

Guidelines for Use

  • NAC is most effective when taken on an empty stomach.
  • If you’ve added a mixed amino acid complex to your NAC regimen, be sure to take it on an empty stomach as well, but at a different time of day than you take the NAC.

General Interaction

There are no known drug or nutrient interactions associated with NAC.

Possible Side Effects

  • NAC has no side effects as long as it is taken in the recommended dosage.
  • High doses of oral NAC may cause gastrointestinal problems, such as vomiting, or in rare cases a rash possibly accompanied by fever.


  • Scientists must still determine how much NAC and glutathione can be safely absorbed and processed by the body.
  • Evidence indicates that in some healthy individuals, high doses of NAC (2,800 mg a day) can act as a pro-oxidant rather than an antioxidant, actually lowering levels of glutathione rather than increasing them. For this reason, otherwise healthy individuals may want to avoid taking high doses of NAC until more information is available.
  • Because there are no adequate studies of NAC in pregnant women, it’s not recommended for women who are or may be pregnant.


Alcoholism – 600-1,000 mg twice a day

Asthma – 500 mg 3 times a day

Bronchitis – Acute: 600-750 mg 3 times a day until recovered.

Chronic: 600 mg twice a day

Cancer – 600 mg 3 times a day

Cancer Prevention – 600-1,000 mg once a day

Cataracts – 500 mg 3 times a day

Flu – 500 mg 3 times a day

Heart Disease Prevention – 500 mg 3 times a day

Macular Degeneration – 500 mg 3 times a day

Multiple Sclerosis – 600 mg 3 times a day

Psoriasis – 600 mg twice a day

Sinusitis – 600 mg 3 times a day between meals

For product recommendations and orders click here for the Natural Apothecary or call 773-296-6700, ext. 2001.

Be well,
David Edelberg, MD

109 thoughts on “NAC (N-acetylcysteine)

    Started taking NAC for the last week but noticing frequent urination so will this eventually stop and how long does this usually last?

    Peter Prak
    Posted July 5, 2023 at 6:47 pm

    My doctor recently recommended 3grams of NAC twice daily for high cholesterol and heart health issues for my husband. I don’t see anyone discussing such a high dose. What are your thoughts? Also, I it, too, but have been experiencing constipation since starting. Is this common? Thanks for the great information!

    Posted February 7, 2022 at 9:36 pm

    How can NAC affect CRPS ? And if there is an MTHFR factor that has an effect on glutathione how much and how often should this be taken ? Is a liquid methylated b vitamins supplement going to be helpful ?

    Jacklyn Reber
    Posted October 6, 2021 at 12:39 am

    Can NAC be taken for auto immune hepatitis? Extensive history with auto immune diseases and pulmonary embolism (one year ago). Currently taking prednisone and Coumadin along with another medication for liver. Also battling pneumonia currently. Approximately one month ago had a pulmonary valve replacement done. And lastly some dental work needs to be done as well. Do you recommend NAC? Asking for my mother who is 67 years old.

    Posted September 23, 2021 at 8:03 pm

    Hi, I recently started taking it. I’ve been wondering if it can cause constipation and a sensation like acid reflex. I take one 600 twice a day. Is there anything one can take to help with that? I already take 400 magnesium daily to help but it’s not cutting it right now. Thank you!

    Posted August 1, 2021 at 12:37 am

    Hi. Can NAC cause more frequent urination as it may be detoxing metals from the body? My daughter has PANS and seems to be urinating more frequently since starting this and seems congested because I’m assuming it’s thinning the mucus

    Posted July 14, 2021 at 6:31 am

      Hi there,

      It’s possible, but please let your daughter’s GP know about this as other causes of frequent urination should be explored.

      Dr M

      Posted July 26, 2021 at 6:18 am

    Hi Chris
    The supplement mix you are suggesting will work well together

    David Edelberg
    Posted April 12, 2021 at 12:54 pm

    Is it okay to take NAC with 5 htp to boost serotonin levels, or how long do they need to take apart? also what about inositol and L-tryptophan with NAC? Thanks doc

    Posted April 11, 2021 at 8:13 am

    Been taking Nac for many things. Anxiety, sinus. But Most recently diabetic retinopathy. My eyes seem to be improving or at least stable. Anyone in here know if NAC has improved eye health in general?

    Posted March 8, 2021 at 1:20 pm

    No problem

    Dr E
    Posted January 27, 2021 at 7:45 pm

      Hello, I recently quit smoking marijuana after heavy use age for over a year. I had severe brain fog, anxiety and other symptoms. I am currently taking one NAC (600 mg) tablet in the morning and one double strength of L-lysine (1000mg) tablet shortly thereafter. Later in the day I take my multivitamin. Today I’ve been experiencing constipation and some occasional stomach pains (nothing too severe). I’ve always had problems using the bathroom regularly and am not sure if the supplements are the cause or if this is just more of the usual.

      Posted February 3, 2021 at 3:14 pm

        Hi Chalon,
        Please consider scheduling a telemedicine visit with Dr. E or another one of our functional medicine providers. They’d be happy to help you get to the bottom of these issues. Our scheduling staff can be reached at 773-296-6700.

        Best wishes,
        Dr M

        Posted February 15, 2021 at 12:45 am

    hello dr .e

    can i take nac with cipro 500 mg 3x daily
    dealing with deep prostatitis infection

    Posted January 26, 2021 at 3:45 pm

    Can I take nac with labetol at the same time. Also nac was suggested to improve egg quality is it safe to keep taking during pregnancy?

    Posted January 4, 2021 at 10:24 am

    In theory, yes, that’s possible. However copper is a relatively minor member of the anticandida armamentarium. NAC on the other hand, has so many ‘positives’ that I would hesitate ever discontuining its use except if causes some side effects or another

    Dr E
    Posted July 21, 2020 at 6:52 am

    Does NAC deplete copper in the body? If yes, is it hypothetically possible that this could cause Candida Albicans to proliferate? In other words, is this supplement recommended if you are fighting yeast overgrowth?

    Michael Tobler
    Posted July 20, 2020 at 7:59 pm

    Is is possible that NAC is making me VERY tired? I have been on it for almost a month for help with skin-picking, 1200mg daily. When I took it in the morning I needed a NAP after lunch. So now I’m taking 1200mg at night.

    Posted July 12, 2020 at 11:56 pm

    I just started NAC for brain fog I am taking three 600 mg through the day. My question is do I still supplement 2 mg copper and 30 mg zinc even though I get a lot of zinc through meat and seeds?

    Posted June 25, 2020 at 4:12 am

    They do not cancel each other and I am unaware of any interactions

    Dr. E
    Posted June 15, 2020 at 5:52 am

    Thank you for this informative site.

    i am currently nebulizing myself with colloidal silver 3ml, was wondering if i should commence NAC 600mg once a day?

    my concern is, do they cancel one another in their interactionsor be toxic?

    thank you

    Posted June 13, 2020 at 10:54 am

    Can NAC be taken with Myo-Inositol?

    Posted June 10, 2020 at 11:55 am

    Instead of taking NAC 2x a day (600mg), can I take 1 a day since I’m new to it and should I take it in the morning or in the evening?
    Thank you!

    Posted May 1, 2020 at 4:06 pm

      Hi Merina –
      Taking it once daily (usually in the morning) should be fine, but you may also want to check with whomever recommended it for you as well.
      Hope this helps
      Dr M

      Posted May 8, 2020 at 2:28 pm

    My seven year old son recently started taking 600mg of NAC every morning to help with ocd skin picking and it has really made a difference. My question is, is it safe for him to take NAC while he is also on a liquid iron supplement 3 ml per day for anemia?

    Posted April 29, 2020 at 8:44 pm

      Hi Chelsie – In this case, it’s best to ask whomever recommended the liquid iron, just to be safe. If you need a second opinion, we can help you with this over a telemedicine consultation with our nurse practitioner Wendy Ploegstra. If needed, you can schedule this through our Patient Services staff by calling 773.296.6700.
      -Dr M

      Posted May 8, 2020 at 2:41 pm

    I started taking NAC because of its ability to thin mucus, but it has caused an awful amount of stomach pain, nausea, and diarrhea. How long after discontinuing NAC will it take for the side effects to stop? Also, do you know if it’s because of my sensitivity to Sulphate drugs that I’m having these awful effects? Thanks

    Posted April 20, 2020 at 4:43 pm

    NAC is helpful for Tricothocene Mycotoxin poisoning, a gas emitted from black mold. many schools and buildings have this issue. There are no state or federal laws against mold in public buildings. Tricothocenes are a biology war weapon. I have mycotoxin poisoning, urine and skin tested.

    Posted April 18, 2020 at 8:00 am

    Hi Sean
    I would get your copper levels measured before considering NAC treatment

    Dr E
    Posted March 22, 2020 at 3:42 pm

    Hi Barbara
    Yes, and yes

    Dr E
    Posted March 22, 2020 at 3:36 pm

    For proactive antioxidant support, should I start with 600 mg/daily? Also, is it okay to take early am with water pill, probiotic, and allergy med (Allegra)?

    Posted March 18, 2020 at 7:36 pm

    Hi….concerning copper supplementation, when should it be taken in relation to the NAC?

    Sean Kearney
    Posted March 12, 2020 at 3:48 pm

    They can be taken together

    Dr. E
    Posted March 10, 2020 at 11:14 am

    Is it okay to take NAC at the same time as SAM-e, or do they ned to be taken an hour apart for absorption?

    Tikkun Olam
    Posted March 10, 2020 at 9:36 am


    I use ritalin for my adhd but ritalin make me anxiosus and nervous.

    i tried nac 2x600mg/day and these side effects gone but now too frequency urine. what can i do about it?

    Cahit Doğan
    Posted March 7, 2020 at 9:15 am

      Hi Cahit –
      This is definitely a question for whomever recommended the NAC. Increased urinary frequency may be due to another cause that should be investigated.

      -Dr M

      Posted March 11, 2020 at 7:58 am

        Nobody recommended nac to me. I have allergies, asthma, rhinit, ocd, adhd, undermethylation. What do you think are some of the underlying causes?

        Cahit Doğan
        Posted March 22, 2020 at 8:05 am

    I was diagnosed with stage 3 adrenal fatigue. I take 800 mg of magnesium, 1800mg of nac(halfofwhatdocrecommend), multivitamin w/zinc and fish oil. I still get occasional muscle twitching and leg achiness. Does this mean Parkinson’s or need more magnesium? I’m worried?

    Posted March 4, 2020 at 3:52 pm

    Reduce your dose to 500-600 mg twice a day and take it with food.You may be able to get all the benefits w/o side effects

    Dr. E.
    Posted March 3, 2020 at 9:09 pm

    Unfortunately I started NAC about 10 days ago and it also seems to be causing increasingly worsening acid reflux and chest pain. It is the only thing different I know of that may be the cause and I am glad to find this thread because otherwise the general info says no side effects. I know it says take first thing on an empty stomach but would it lessen the reflux if I took before bed or midday after meals? I really do not want to take a PPI as I am only taking this for liver detox and some brain memory help. The dose is 2 1200 mg tabs in am which after reading this thread may be high

    Lori Deanne
    Posted March 1, 2020 at 7:46 am

    I take Synthroid when arising each morning (on an empty stomach). Can I take NAC the same time as the Synthroid or should I wait for another time in the day between meals? Thank you.

    Posted February 28, 2020 at 6:50 pm

      Hi Janine –

      It’s always a good idea to take synthroid on its own, unless directed otherwise by your prescriber.

      Hope this helps!
      Dr M

      Posted March 2, 2020 at 12:58 pm

    It’s quite safe for long term use

    Dr E
    Posted February 24, 2020 at 8:06 am

    HI I WAS WANTING TO KNOW HOW LONG YOU CAN TAKE Nac for,my daughter was put on it for eating disorder in June 2019, she takes3 pills am and 3pills in pm,all her blood work is fine,she doing much better,was wondering at what point do she need to discontinue NAC?

    Posted February 16, 2020 at 10:10 pm

    I started taking NAC today for asthma because I don’t like the side effects of daily corticoid inhalers, and I use my rescue inhaler too often. I am seeing mixed reviews on NAC for asthma. Does it truly help asthma?

    I have a clean, anti-inflammatory diet. I am also taking pycnogenol, DHA/EPA and vit D for inflammation.

    Posted February 12, 2020 at 9:57 am

      Hi Sarah –

      NAC can help with asthma, but if you’re using your inhaler too much, it’s best to discuss this with whomever prescribed it. There are many options for asthma management; NAC may be helpful, but it might be useful information for your general practitioner to know that you’re using your inhaler too frequently. There may be a better inhaler or other therapy for you that you might be able to use with NAC if you choose. It’s best, however, to talk with your prescriber about all of this so that you’re making decisions together.

      -Dr M

      Posted March 2, 2020 at 1:30 pm

    Yes. Just drink plenty of fluid during the day to dilute this effects]. It is harmless

    Dr E
    Posted January 27, 2020 at 8:13 pm

    Can taking 500mg of N-A-C a day cause a very strong urine?

    Nancy Griffo
    Posted January 26, 2020 at 6:04 pm

    Hi there, my daughter just started taking NAC for OCD skin picking disorders, she’s 15. How long should we wait to see if it is actually working and what dose is usually recommended for a teen? She was told to end up on 1200mg morning and night so total 2400/day.
    thank you!

    Posted January 19, 2020 at 5:50 pm

    Hi Joe
    Everyone is biologically unique. Generally side effects and drug interactions are minimal but there will always be a few people who will react to it adversely

    Dr E
    Posted December 20, 2019 at 8:09 pm

    This site states “There are no known side effects as long as it is taken in the recommended dosage.” And this “There are no known drug interactions associated with NAC.” Well if you read the comments above then there are side effects, many, so which is true?

    Joe Arsanis
    Posted December 18, 2019 at 8:49 pm

    For chronic pain take Ty#3(2×300 mg tabs daily presently taking 1×600 mg NAC daily fir abt 6 mths do I need to stop fir a time if so how long before going back on the NAC

    Mary H
    Posted November 12, 2019 at 4:46 pm

    Does NAC affect the kidneys?

    Posted October 31, 2019 at 5:15 pm

      Can NAC cause constipation? Since starting, I’ve been taking 3x day for 3 months for excess mucus/sinus pain which has helped tremendously but my digestion has slowed down significantly. Stomach pain,burning, nausea, back pain, severe constipation, I can feel the stool slowly moving through my intestines its lasted 2 months very painful.
      Thank you!

      Posted January 28, 2020 at 12:23 pm

      Is it ok to take NAC before going to bed while taking Alpha lipoic acid in the morning?

      Posted April 18, 2020 at 5:52 am

    You can reduce your dose to twice a day and maintain it. Periodically have your doctor check your liver enzymes. If they remain normal, you probably don’t need the NAC

    Dr E
    Posted October 29, 2019 at 4:56 am

    I had hepatitis in the 90’s. I’m having hot flashes in post menopause so I’m hoping the NAC helps me with my liver and detoxification. I take three 600 mgs. daily. How long can a person take it?

    Posted October 19, 2019 at 11:14 pm

    None that I am aware of

    Dr E
    Posted July 29, 2019 at 11:43 am

      Thank you. Is it ok to take NAC while taking prednisone?

      Scott B
      Posted July 31, 2019 at 8:13 pm

    Are there any interactions or does NAC reduce the effectiveness of Bactrim?

    Scott B
    Posted July 18, 2019 at 8:26 pm

    Alma: yes dry mouth is a possibility but there are many causes of this. First, stop your NAC and see if mouth moisture improves. If not, have your doc look for other causes

    Noreen: yes, all can be taken together

    Dr E
    Posted July 16, 2019 at 9:47 am

    Can I take nac at the same time as calcium, vitamin e and c, and zinc? Those are my early morning supplements before I eat (1/2 hour to 1 hour later)

    Posted July 6, 2019 at 5:25 pm

    Can NAC leave you with dry mouth and nasal passage? I am tryint to figurecoutvehatvis causing it. I take 1200mg a day. My dry mouth stsryedvappearing coincidentally as I stsrted taking NAC.

    Alma Rivera
    Posted July 4, 2019 at 3:06 pm

    I suggest separating them by a couple of hours as either one can be a little upsetting to your stomach

    Dr E
    Posted May 17, 2019 at 11:22 am

    Can I take NAC with Doxycycline??

    Posted May 16, 2019 at 10:04 pm

    You can go to 2,000 mg

    Dr E
    Posted May 7, 2019 at 9:19 am

    Hi, i have been taking nac for a month and it was working great for myxedema (mucin) got rid of it in my face and neck and it has stopped working I currently take 1,500 mg 3 capsules throughout the day w vitamin c should I increase?? Thank you!

    Anne Marie
    Posted May 4, 2019 at 1:29 pm

    Yes, you can. The two do not conflict

    Dr E
    Posted April 13, 2019 at 8:32 am

    I take adderall in the morning on an empty stomach, can I take NAC with it in the morning and vit C at night?

    I have OCD and high blood pressure. I take lisonipril at night. I also have sleeping problems.

    Posted April 4, 2019 at 8:56 am

    Yes, the effect can wear off (just like many prescription meds). Try increasing your dose by a capsule daily and if you want to add a natural supplement to this, ask for Deplin, a prescription vitamin B that can enhance the NAC

    Dr E
    Posted February 21, 2019 at 5:37 pm

    Does the effectiveness of NAC supplementation wear off over time, for OCD-like symptoms? I’ve been taking it for a few months. At first it was wonderful, but now my inertia is worse than ever and I ‘m having more difficulty stopping a compulsive activity.

    Posted February 20, 2019 at 10:26 pm

    You’re making the situation more complicated than it deserves. Years ago, I learned from nutrition guru Dr Alan Gaby that amino acids should be taken on an empty stomach. This means take them when arising. If you take them with food, especially the high protein content of a carnivore diet, the aminos in your diet will interfere with the aminos (including NAC) you are taking

    Dr E
    Posted January 26, 2019 at 11:31 am

      Carolyn, There is a new treatment out for OCD and it is called TMS Therapy (Transcranial Magnetic Stimulation) Google that above and learn where the closest one to you is located. It is non invasive, you are treated for approximately 20 min, no pain, you attend 5 days weekly for 5-6 weeks. Many insurance companies pay the fee, which is approx., $12,500
      Yes, lots of money but they get a break in amount to be paid. Also inositol works for many but not all. Inositol powder, there is a formula to follow however at the end of the taking 18 Grams you are not finished. At that time you must continue the 18G for another 6 weeks to avoid relapses. I will leave my email, however this site may delete it, I don’t know. Best of luck, Joseph

      Joe Arsanis
      Posted December 18, 2019 at 9:03 pm

    Great thread. I’ve been reading about Amino Acids competing with proteins for absorption.

    In the morning, I need some warm drink with fat (tea with goat milk is my go-to) before I can get myself going. Do I need to wait 2 hours, as if I’ve had a meal, before taking NAC?

    Can I take another Amino Acid or Enzyme supplement 30 minutes later, and consume protein again after that?

    I’m trying to space out the dosage for all the supplements that have been recommended to me for optimal absorption, and feel there aren’t enough hours in the day! Any information would be helpful. For autoimmune reasons, I’m on a carnivore diet until I see improvement since it has, so far, been the only significant and positive change I’ve experienced in symptoms. If need be, I can eat just once a day, just trying to time the goat milk, broth, and meal accordingly.

    I should be on 1200-1800 mg NAC as well as Neprinol, amongst others. Both empty stomach supplements, both competing, as far as I can tell from my research. THANK YOU!!!

    Hilary Bills
    Posted January 25, 2019 at 3:35 pm

    There would be no problem adding this

    Dr E
    Posted December 10, 2018 at 4:33 pm

    I suffer from PRIMARY LATERAL SELOROSUS(Motor Neuron Disease)
    And I am going taking already daily twice
    L Serine 500 mg
    Coq10 400mg
    Maca Root
    Berberine 900mg
    Omega 3 fish oil 3600m
    Magnesium 833 mg(once daily)
    Since one week upto now everything normal.

    Is it safe to take NAC with this.
    Please suggest

    Posted December 10, 2018 at 5:04 am

    Can NAC supplementation cause fatigue?

    Posted August 30, 2018 at 12:50 pm

      Hi Anjana. NAC usually does not cause fatigue.

      Dr. R
      Posted August 31, 2018 at 7:36 am


    I bought NAC after my psychiatrist recommended but it’s making me feel really tired after I take it 🙁 I really want to continue as its meant to help my condition a lot. I can already feel I am alot more focused, I have ADD. Is there any way to avoid this from happening? I am taking it at night only, but feel almost hung over the next day. I am taking powder too mixed with water, could this be affecting it? Thanks in advance!

    Posted August 23, 2018 at 6:57 am

    Can NAC help with mixed connective tissue disease (autoimmune)?

    Posted July 17, 2018 at 11:22 am

      Hi Antoinette. NAC as an adjunct therapy may be helpful especially with the inflammatory component of autoimmune disorders. In addition, lifestyle changes, including anti-inflammatory diet, possible gluten-free and dairy-free diets, moderate exercise, and stress reduction, will all be helpful. Remember, these are adjunctive therapies and not a replacement for treatment your doctor may recommend.

      Dr. R
      Posted July 17, 2018 at 1:58 pm

    I am taking antibiotics (Keflex) for my recurrent Urinary tract infection. I heard NAC disrupts bacterial biofilms and prevents chronic UTI. Can I take NAC and antibiotics together?

    Posted June 5, 2018 at 6:21 am

      Chloe. Yes. There should be no interactions using NAC with Keflex.

      Dr. R
      Posted June 5, 2018 at 1:10 pm

    There are several article in conventional psychiatry journals on the use of NAC for OCD and I find psychiatrists are actually recommending it.
    No problems using NAC with root canals

    Dr E
    Posted May 28, 2018 at 1:06 pm

    DR R. I have 2 roots canal, can I take NAC safelely?

    denise brickel
    Posted May 27, 2018 at 5:35 pm

    I am taking NAC 600 mg twice a day for anxiety and OCD. I also take an iron supplement (325 mg twice a day) to keep my ferritin up. Are these ok to take together on an empty stomach with fruit juice?

    Posted May 25, 2018 at 7:52 pm

      Do not take 325mg of iron, that is an insane dose. You can damage your organs and cause iron overload.

      Vinnie Valentine
      Posted December 18, 2019 at 7:47 am

    I know NAC detoxifies. How long should I wait to take other meds and supplements to insure that they are effective?

    Posted May 17, 2018 at 7:42 pm

    How long should you take NAC? I have been through one bottle which I purchased for PCOS and I’m now not sure if I should buy another one. It is something your body needs a break from? Like three months on and then a month off?

    Posted May 14, 2018 at 10:13 pm

      Chris. If you’re improving, I’d suggest you continue for another month or so. Discussion with your primary care physician is always recommended as she/he is familiar with your overall health.

      Dr. R
      Posted May 15, 2018 at 7:32 am

    Hi, I undestand nac needs to be taken on an empty stomach but what about tea ? I drink Mate Tea first thing in the morning & wonder how long I have to wait for my nac dose. I only just started after a pleurisy which is almost gone. Thanks

    Posted May 9, 2018 at 4:37 pm

      Dominique. The tea shouldn’t be a problem.

      Dr. R
      Posted May 10, 2018 at 7:26 am

    Please tell be about NAC and Lyme disease.

    Debra Fleming
    Posted February 9, 2018 at 11:36 pm

      Hi Debra
      NAC may help to inhibit biofilm formation by the bacteria. This would be one piece of a very complex treatment regime that would need to be individualized for a patient with Lyme and/or other co-infections.

      Dr. R
      Posted February 10, 2018 at 12:24 pm

    Take. NAC with Vitamin C. 600 mgs NAC 500mgs C

    People with MTHFR should NEVER take copper as a supplement without testing their copper/zinc/ceruloplasmin levels. It’s far more common to see a copper overload for people with MTHF mutations. Also Hydroxy B-12 is safe for all, Methyl B-12 can still cause issues.

    Posted January 5, 2018 at 3:46 pm

    Hi. My former doctor told me to take 600 mg NAC twice a day for obsessive-compulsive tendencies. Recently I accidentally ordered two bottles of 1000 mg NAC. I don’t want to waste them, but I am concerned about how safe it would be to take that much. Would it make sense to just take one capsule a day? Like in the morning so that its benefits would be seen during the day?

    Posted November 25, 2017 at 1:11 am

      Ann. That would work or break the tablet in two.

      Dr. R
      Posted November 26, 2017 at 11:03 am

    Hi Laura
    Both prescription medications and supplements can cause side effects in some people and with your NAC this definitely seems to be the case. I suggest simply stopping it and if all these symptoms go away in a couple of days, don’t bother with NAC anymore

    Dr E
    Posted September 14, 2017 at 9:28 am


    I have been taking NAC for 2-3 weeks – 600mg daily. I have heart rhythm problems and “foggy head”. These pills seems to be making me more dizzy and VERY tired. Could this be the pills? Also, how long should a person take NAC for before people feel the correct way – should it be immediate or after a few months as i’m wondering whether to stop or push through. Thanks

    Posted September 14, 2017 at 3:08 am

    Hi Majid
    Natural treatments, including NAC, have been disappointing. You might get yourself tested for the MTHFR gene. If you are positive, some people are benefitting from methylated B-12, folate, combined with zinc and copper
    Good luck!

    Dr E
    Posted March 23, 2017 at 8:01 am

    I am taking 600 mg two times a day on empty stomach for vitiligo without copper and zine, though many research says zinc and copper are two super minerals that helps for vitiligo. Will it help me please.

    Posted March 21, 2017 at 11:30 pm

    I tried taking NAC, 600ml twice a day but had to stop as it was
    Making me dizzy and feeling terrible and couldnt sleep. I looked up possible side effects and it can cause these problems. Also Dr.
    Mercola suggests not to take NAC if you have dental amalgams, as since NAC is a natural detoxifier of mercury it could effect your Mercury detoxification.

    Posted March 14, 2017 at 7:36 am

    How soon after I eat can I take an NAC? and by what time should I take the last NAC supplement? I also take milk thistle and caprlylic acid. Should I take them together or separately?

    Posted May 10, 2016 at 4:40 am

    Is this supplement helpful in treating bi-polar disorder?

    Posted January 7, 2016 at 11:24 am

    thanks so much for the rresponse…most helpful.

    Charles Willliams
    Posted May 20, 2015 at 9:32 am

    I have the same problem with NAC myself. Taking it with a proton pump inhibitor like Nexium will help, or, if you’re using it as an antioxidant, try a new form of glutathione from Xymogen instead

    Dr E
    Posted May 18, 2015 at 9:52 am

      Thanks for the info for it was most helpful.

      Charles Willliams
      Posted May 20, 2015 at 9:31 am

    Can someone tell me what I can take NAC with for a better digestion experience. I’ve only taken this once but it stirred up an already active acid redux condition. Would taking it on an empty stomach help this?

    Charles Williams
    Posted May 18, 2015 at 12:21 am

      I had the same problem at first. Maybe do what I did and lower your dosage to 500 mg twice daily 2 hours between meals either before and or after. It got better after one week I had lost apatite and felt nausea but now feel like I’m 20 years younger and won’t miss a dose!!!

      Shawn Berube
      Posted April 17, 2020 at 8:24 pm

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