Glutathione Side Effects : What Are They?

Many people would like to know what are glutathione side effects?

To start off with, it would be good to know what glutathione is and what functions it has in the body. Click here for a quick refresher. glutathione side effects So now we need to know : What are the side effects of glutathione?

This is a tricky question, since this question usually comes up with drugs or pharmaceuticals. We want to know if we take drug X, what are its side effects?

So naturally based on this reasoning, we may ask if we take glutathione, side effects that may follow would be what?

To begin with, glutathione is a naturally occurring substance in each of your cells.

So we will use the terms glutathione and natural glutathione interchangeably on this page.

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So you could say that glutathione side effects are antioxidation, immune system building, detoxification, energy and anti- aging. Not bad for a list of so-called side effects!

To illustrate this, we all know that we have blood in our circulatory system, and this is made up of white blood cells, red blood cells, plasma, and platelets.

We could ask the question, “What are the side effects of white blood cells?”

Well, they fight infection, but really, we don’t ask that question, because we know they are naturally occurring, we need them, and they play a positive role in the body.

They fight infection, and without them, we would be dead from some kind of illness or infection.

It’s the same with glutathione, yet it is still such a new word to many that immediately the assumption is made that if we take it, there must be glutathione side effects.

Here's an interesting fact : You would be dead right now if you didn’t have glutathione in each and every one of your cells quietly doing it's job.

So asking the question “What are glutathione side effects?” would be similar to asking “What are the side effects of white blood cells?” The answer is all positive things that are necessary to your bodily function.

While that may be the exact answer to your question, what are glutathione side effects, it may not be what you were looking for. Let’s see if we can cover that now.

You might want to know, "Can I just take a glutathione pill?"

Glutathione, when taken orally as a glutathione pill, or in any other form, including reduced glutathione, is destroyed in the digestive tract, and so glutathione side effects when taken directly by mouth would be none, good or bad.

It might make your wallet a little lighter though!

Perhaps a better way to phrase the question would be : “What would be the side effects of glutathione if I raise glutathione in my body?”

There are several ways to raise glutathione in the body, so this refresher would be a good one to read before going further.

Click here if you would like to know all of the ways to raise glutathione.

So now we may be asking : “Ok, I understand there are no side effects from taking glutathione. I can't take a glutathione pill. I must take in the building blocks or precursors. So what are the side effects on my glutathione system?”

Ah, good question. I am so glad you asked.

Raising glutathione may have some side effects that vary depending on the building blocks you use.

We will consider some of the main precursors for natural glutathione and the glutathione side effects that result with them here. If you see a way to raise glutathione on the page for all the ways to raise it, and you don’t see it below, then there are not currently any reportable side affects associated with it.

We will report on the two most well studied and effective ways to raise glutathione - N-acetyl-cysteine and Undenatured Whey Protein, along with other lesser ways including SAM, L-Cysteine, L-Methionine, and Silymarin.

The glutathione side effects mentioned below will be in addition to the positive glutathione side effects that were already mentioned above.

So in considering your choices, weigh all possible negative glutathione side effects against the positive ones which apply to all the ways to raise natural glutathione mentioned below.

Remember, you absolutely have to have glutathione in your cells to be alive and healthy. Period.

And if you are over 40 or have any chronic health condition, you are likely deficient in this, and will benefit from raising your glutathione levels.

So read on, my friend!

We will give you all of the information you need right here. Evaluate this information, and take charge of your health today.

Choose the method for raising glutathione that is right for you, and you will have great health!

Side Effects Of Glutathione : N-Acetyl-Cysteine

N-acetyl-cysteine is a pharmaceutical over the counter drug that has been used in emergency medicine for years in treating acetaminophen overdose.

It is very effective when given in large doses in an emergency room setting when someone is going into liver failure from an overdose of acetaminophen, the active ingredient in Tylenol. Using something on an emergency basis is one thing, using it daily for health reasons is quite another.

There is a popular glutathione enhancer on the market that contains N-acetyl-cysteine as its main active ingredient, and it is recommended to be taken twice daily to raise glutathione levels.

The box label says: "Caution: This Product is for adult use only. It is not for use by young children, pregnant women or nursing mothers. Allergy warning: This product contains ingredients derived from shellfish and mushrooms."

What are the possible glutathione side effects of N-acetyl-cysteine?

Always check with your

medical practitioner before deciding on any treatment for raising your glutathione if you have any questions or concerns.

The main side effects with N-acetyl-cysteine have to do with its short half life and toxicity. They include the following:

  • Short half life, so has to be administered several times a day to be effective
  • Upset Stomach
  • Diarrhea
  • Fatigue
  • Skin rash

*Repeated overdoses will cause the allergic reaction to progressively worsen.

If you have asthma or bleeding problems, your doctor may tell you to avoid N-acetyl-cysteine. You will likely be told to stop N-acetyl-cysteine 2 weeks before any elective surgery.

If you're pregnant or breastfeeding, you must check with a doctor before using N-acetyl-cysteine supplements.

If you take any medicines regularly, talk to your doctor before you start using N-acetyl-cysteine supplements. They could interact with nitroglycerin, including blood thinners and certain blood pressure medicines.

Dietary supplements are not regulated by the FDA in the same way that food and drugs are. The FDA does not review these supplements for safety or efficacy before they hit the market.

The above information is taken from WebMD and may be found here.

In addition, there is another WebMD report on prescription N-acetyl-cysteine Oral:

You can view this page in its entirety here.

(this page opens in a new window)

Some find the taste and smell unacceptable, due to the sulfur content, it is similar to rotten eggs.

Regular N-acetyl-cysteine usage for raising your glutathione is not recommended for infants and small children.

A recent study done at the University of Virginia School of Medicine indicated that N-acetyl-cysteine usage in rats developed pulmonary arterial hypertension (PAH) that mimicked the effects of chronic hypoxia. They also found that this was "an unanticipated adverse effect of chronic NAC administration and introduce(s) a new animal model of PAH."

This leads to pulmonary arterial hypertension (PAH), a serious condition characterized by high blood pressure in the arteries that carry blood to the lungs.

"NAC fools the body into thinking that it has an oxygen shortage," said Dr. Ben Gaston, UVa Children's Hospital pediatrician and researcher who led the study. "We found that an NAC product formed by red blood cells, know as a nitrosothiol, bypasses the normal regulation of oxygen sensing. It tells the arteries in the lung to 'remodel'; they become narrow, increasing the blood pressure in the lungs and causing the right side of the heart to swell."

You can view the study on PubMed

here. (this link opens in a new window)

For further commentary on the implications of this study which includes the quote above from Dr. Gaston, click here.

It is clear that more research needs to be done to determine the safety of long term chronic usage of NAC as a daily supplement. It should be noted that treating drug overdoses or acute pulmonary disease with N-acetyl-cysteine requires monitoring by a health professional.

Suggested non-prescription oral doses range from 200-2,400 mg/day depending on one’s health.

There are further reactions to N-acetyl-cysteine found here:

ADVERSE REACTIONS: N-Acetyl-Cysteine or NAC:


Anaphylactoid reactions / Rapid / 7.9-17.0 Bronchospasm / Rapid / Incidence not known


Sinus tachycardia / Rapid / 3.0-5.0 Edema / Delayed / 1.2-1.6 Hypotension / Rapid / 0.1-0.1 Erythema / Early / Incidence not known Dyspnea / Early / Incidence not known Stomatitis / Delayed / Incidence not known Hemoptysis / Delayed / Incidence not known Wheezing / Rapid / Incidence not known


Urticaria / Rapid / 6.1-7.6 Flushing / Rapid / 6.1-7.6 Pruritus / Rapid / 4.1-4.3 Rash (unspecified) / Early / Incidence not known Rharyngitis / Delayed / Incidence not known Nausea / Early / Incidence not known Vomiting / Early / Incidence not known Dysgeusia / Early / Incidence not known Drowsiness / Early / Incidence not known Fever / Early / Incidence not known

The above information with full prescribing information may be found here.

Side Effects Of Glutathione : Raising it with SAM

Natural glutathione may also be raised to a certain extend with SAM or S-Adenosyl-Methionine. SAM is also a drug, it is expensive to make, and may not mix well with other antidepressants.

Glutathione side effects from raising it with SAM may include:

  • Dry Mouth
  • Agitation
  • Gastrointestinal Problems

Side Effects Of Glutathione : Raising it with L-Cysteine

L-Cysteine or free cysteine has a negligible impact on raising glutathione levels, as it is quickly oxidized in the digestive tract just like oral glutathione.

In addition, possible glutathione side effects of raising it with L-Cysteine include:

  • Hypercysteinemia (a toxic condition marked by excessive cysteine)
  • Toxic By-Products like the OH free radical. This defeats its purpose as an antioxidant.

Side Effects Of Glutathione : Raising it with L-Methionine

Methionine is also a building block for raising glutathione.

However, above certain doses it can be toxic.

Also, methionine is a precursor for homocysteine, which has been identified as a high risk factor in the development of hardening of the arteries.

Side Effects Of Glutathione : Raising it with Silymarin

What are the side effects of raising glutathione with silymarin or milk thistle?

Possible glutathione side effects are:

  • Gas
  • Cramps
  • Diarrhea

Side Effects Of Glutathione : Raising it With Undenatured Whey Protein

Two of the best well known ways for raising glutathione are with N-Acetyl Cysteine, which was considered above, and undenatured whey protein.

For a brief review or to learn more about strengthening your glutathione system with undenatured whey protein, click


There is a particular brand of undenatured whey protein that has been extensively studied for over 30 years now.

It is a nutraceutical, or medicinal food. It is named Immunocal, and it delivers bonded cysteine to the cells where you can make glutathione right there in your cells.

To find out the glutathione side effects from raising your glutathione with Immunocal, you may refer directly to the

Physician’s Desk Reference (this link opens in a new window) listing for it.

We will include in this listing of glutathione side effects also who should not take Immunocal, so you have all of the information for your consideration.

Most of these are listed on every box of Immunocal, and I will summarize them here:

Considerations For Those Evaluating Immunocal:

  • Patients with a known allergy to milk proteins , should not take Immunocal. This is different than lactose intolerance, since the lactose has been removed. It contains less than 1% lactose and is therefore well tolerated by lactose-intolerant individuals.

    The best way to know if you are allergic to milk proteins is if you know for a fact that you were allergic to your mother's breast milk as an infant, and as a result were unable to breastfeed. This is quite rare.

    If you were able to breastfeed, then you can safely take Immunocal.

  • Patients on a protein restricted diet should take into account that there is 9 grams of protein per pouch.
  • Patients undergoing immunosuppressive therapy should discuss the use of this product with their health practitioner.

    The reason for this is if you are on drugs to keep your immune system suppressed or working at a lower level, Immunocal could theoretically interfere with these drugs by allowing your immune system to be stimulated.

    This would be especially important if you have recently received an organ transplant and are taking drugs to make sure you do not reject the organ.

    It should be noted that there are no documented cases of Immunocal interfering with an organ transplant, but this is stated as a general precaution.

Immunocal is a dry powder, and needs to be mixed to be consumed. Glutathione side effects with Immunocal may include the following if not mixed properly :

  • Gastrointestinal Bloating
  • Cramps

This can be prevented by mixing it appropriately with a liquid or food as instructed.

  • A transient urticarial (hive)-like rash may appear in rare individuals that are undergoing a severe detoxification reaction. This rash goes away when the product intake is reduced or stopped.

I have not personally known anyone that has had this reaction, called a Herxheimer Reaction, but as mentioned, you can reduce the amount or stop it completely.

I have known of individuals who were detoxing and felt sluggish or nauseous, and I recommended they get extra rest and drink plenty of water, half their body weight in ounces, and this phase usually passes within a few days depending on the individual.

This is an indication that you have a heavy toxin load, and the glutathione, through your liver and kidneys, is trying to remove the toxins from your system.

Since you detoxify in your sleep, and water hydrates you and keeps things moving, water and sleep definitely help you to flush these liquefied toxins from your system.

For more on these glutathione side effects, please see the page on detoxification here.

Lastly, you may want to know , "Can I take too much or accidentally overdose on glutathione? What are the side effects of a glutathione overdose?"

The Physician's Desk Reference tells us that when we take the building blocks for glutathione, the cell makes just as much as it needs, and no more. If you take in more building blocks than you need, Immunocal is a protein, so the excess would be used as such in the Krebs cycle. The Krebs cycle is a series of chemical reactions used by all aerobic organisms to generate energy through the oxidization of acetate derived from carbohydrates, fats and proteins into carbon dioxide and water.

Additionally it is noted that overdosing on Immunocal has not been reported.

Always use good sense and follow recommended guidelines when taking any glutathione enhancer, whether it be pharmaceutical (drug) or nutraceutical (food).

In conclusion, what are the side effects of natural glutathione? They are anti-oxidation, immune system boosting, detoxification, energy, and anti-aging.

There are many ways to raise glutathione, so we may also ask what are the glutathione side effects of raising it with several precursors?

The best studied ones are N-acetyl-cysteine and Immunocal. Compare the potential side effects with each one, as well as the lesser ways mentioned above, and weigh them against the positive glutathione side effects that are true of each and every one of these substances.

Do your research, and make the best choice for you!

Dr. Jimmy Gutman is the world's most published author on the subject of glutathione. His latest bestseller is entitled: "Glutathione - Your Key To Health".

buy Immunocal

Good Health To You!

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