Glutathione is an antioxidant that naturally occurs in the body. It is important for preventing damage to cells from free radicals. While the research is ongoing and not always conclusive, glutathione is being used as a supplement and treatment for a variety of conditions. Conditions affecting the ear, nose, and throat that involve oxidative stress are being treated. Some doctors have even begun prescribing glutathione intranasal as an experimental treatment for Parkinson’s disease. Because of the low reported incidence of side effects, many doctors are prescribing this treatment off-label to help their chronically ill patients.

What is Glutathione?

Glutathione is a potent antioxidant made from the amino acids cysteine, glutamate, and glycine. It occurs naturally throughout your body and helps prevent damage to cells by free radicals. It also seems to have a way to remove certain pollutants and harmful chemical from the body. Glutathione levels tend to decrease with age, and this decrease is sometimes associated with common conditions in elderly patients. The actual deficiency that occurs with age is likely related to glutathione’s precursors – cysteine and glycine – as there is an association with decreased protein turnover with age. View Article (opens in new window): Deficient synthesis of glutathione underlies oxidative stress in aging and can be corrected by dietary cysteine and glycine supplementation. Glutathione deficiency has been associated with a wide range of conditions including diabetes, liver disease, Parkinson’s disease, Alzheimer’s, and immunological conditions.

Administering Glutathione

When trying to raise glutathione levels with an oral treatment, raw materials/precursors of glutathione are often used such as cysteine. Certain oral supplements like N-acetyl cysteine and milk thistle may also enhance the body’s ability to produce glutathione. N-acetyl cysteine is often given to raise glutathione and treat toxicity form acetaminophen overdose.

There is conflicting evidence on whether directly administering oral glutathione may or may not be effective. The oral bioavailability of glutathione is low and it may not be able to be processed by the body effectively unless it is formulated in a certain way. It may be that oral glutathione can increase levels in individuals who have low glutathione but not in individuals with more balanced levels. Research is continuing in this regard. View Article (opens in a new window): Effects of Oral Glutathione Supplementation on Systemic Oxidative Stress Biomarkers in Human Volunteers

Intravenous glutathione has been used however this method of administration carries some risks and is not widely available to all patients. It has been shown to effectively improve Parkinson’s symptoms and avoids the issues with oral administration and absorption. However it is an invasive treatment that has risks and is not convenient in many cases. Sublingual administration is another method that has been studied but there is not enough conclusive evidence.

One of the more promising methods of administration is through a nasal spray. Glutathione is a small molecule that can potentially be absorbed without enhancers when administered intranasally. Studies have shown this method may allow glutathione to cross the blood/brain barrier to help treat Parkinson’s disease.

Glutathione and Parkinson’s

It has been shown that in patients with Parkinson’s disease, levels of glutathione are deficient by about 40-50% from a healthy individual. The exact cause of this disease has not been fully determined but one associated mechanism of action is oxidative stress – of which glutathione plays an essential role in managing. An early marker of Parkinson’s development is glutathione deficiency. Because of this, supplementation with glutathione has been considered a potential treatment.  View Article (opens in new window): Potential use of glutathione as a treatment for Parkinson’s disease

Glutathione supplementation is relatively safe with few side effects. For this reason, many patients and doctors are willing to try using it to treat Parkinson’s even with the evidence being preliminary. In a Phase II study it was shown that patients receiving a high dose of intranasal glutathione had an approximate four-point improvement in PD severity score, as measured by the Unified Parkinson’s Disease Rating Scale (UPDRS).

Intranasal glutathione is a non-invasive way of administering glutathione that may be able to effectively raise glutathione in the body. Since the target of glutathione administration in Parkinson’s disease is the CNS, oral administration is unlikely to have a significant effect. Intravenous administration may be effective, but it is costly, has a higher risk of side effects, and is impractical for many patients on a regular basis.

Intranasal glutathione has actually been prescribed by doctors for many years prior to the recent clinical trials for Parkinson’s disease. A study that was designed to assess the safety of intranasal glutathione surveyed 70 patients, and over 86% of respondents considered the nasal spray to be comfortable and easy to administer. In addition, 62.1% reported having experienced health benefits they attributed to intranasal glutathione. View Article (opens in new window): Safety Survey of Intranasal Glutathione.

Further Research

While doctors already prescribe intranasal glutathione frequently, the research is ongoing to determine the most effective dosing and instructions for use in the clinical setting. Many drugs are used off-label successfully, including compounded drugs like intranasal and topical glutathione.