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Multiple Chemical Sensitivity (MCS)

Multiple Chemcal Sensitivity (MCS) or idiopathic environmental intolerances (IEI) is a is a chronic condition and syndrome where a person is adversely affected by exposure to low-level chemicals such as scented products, perfumes, petrols, pesticides, plastics, synthetic fabrics, smoke, and paint fumes. Symptoms are not specific meaning they are common symptoms to many other illnesses such as nausea, dizziness, and inflammation of skin, joints, gastrointestinal tract and airways.

Some researchers are of the opinion that Multiple Chemical Sensitivity is due to immune system damage or malfunction, which may produce reactions from all sorts of triggers rather than a specific reaction to one toxicant.

The body has a high stress response to scents and symptoms experienced are very real and can be disabling. MCS patients can also react strongly to placebos if they believe they are smelling chemical stimuli. Mental health conditions such as anxiety, depression and somatoform disorder are commonly associated conditions with MCS.

1. Latest News

1. Latest News

Latest news on MCS from The Chemical Sensitivity Foundation.

2. Symptoms

2. Symptoms and Treatments

Note: Always seek advice from a doctor before beginning any listed treatments. Treatments can affect everyone differently.

Multiple Chemical Sensitivity Symptoms

The possible list of symptoms varies from one patient to another. Symptoms of MCS are very similar to those patients with Chronic Fatigue Syndrome (CFS/ME) and many people with CFS/ME have MCS as well. Here is a list of possible MCS symptoms.

  • burning, stinging eyes

  • wheezing, breathlessness nausea

  • extreme fatigue/lethargy

  • headache/migraine/vertigo/dizziness

  • poor memory & concentration

  • runny nose (rhinitis)

  • sore throat, cough

  • sinus problems

  • skin rashes and/or itching skin

  • sensitivity to light & noise

  • sleeping problems

  • digestive upset

  • muscle & joint pain.


Treatment for MCS tends to focus on the underlying cause and desensitisating the patient as opposed to addressing symptoms individually.

Medical Treatments

Chemical Avoidance for Multiple Chemical Sensitvity:

By avoiding the trigger the patient not only avoids acute symptoms but also lessens the toxic load of their system and allows the hepatic detoxification pathways to more efficiently inactivate toxic substances and eliminate them from the body.

Professional Support:

Working with a trained practitioner can assist you to develop skills to calm anxiety and can also equip you with knowledge to find your next steps towards wellness. Please ensure that you find a practitioner who understands how to navigate the territory of complex chronic health conditions.

Alternative Treatments

Detoxification Support for Multiple Chemical Sensitivity:

Raising glutathione levels in patients that are "slow acetylators" may improve there detoxification pathways and help with their MCS condition. This can be done by supplementing with N-Acetyl-Cysteine and alpha lipoic acid and also Milk Thistle.

Phosphatidylcholine (PC) for Multiple Chemical Sensitivity:

Is a fatty substance which in large dosages (both orally and intravenously) can help support cell membranes by replacing the PC damaged by toxins and currently comprising the cell membranes, thus restoring cellular health and detoxification efficiency.

The Martin Pall Protocol for Multiple Chemical Sensitivity:

A combination of supplements to assist people with CFS/ME and MCS. More info

The Doctor Grace Ziem Protocol for Multiple Chemical Sensitivity:

A supplement protocol to assist patients with MCS. More info

DHEA for Multiple Chemical Sensitivity:

An adrenal hormone which is available as a supplement to take. It modulates neurotransmitters in the brain in the limbic system (the emotional and stress centre of the brain).

Far-Infrared Saunas for Multiple Chemical Sensitivity: 

An option for detoxification which has less side effects than traditional hot saunas.

Mindfulness for MCS:

is a set of skills for healing, intuition, insight, calmness, focus, resilience and hope that you can develop to counter the stresses that chronic illness brings. You can literally "train your mind to promote healing. Mindfulness has a positive flow on affect into every aspect of a person’s life. More info

Brain Retraining Techniques (Ashok Gupta, Annie Hopper etc) for for Multiple Chemical Sensitivity:

Using mental exercises to rewire the neural connections that are causing the brain to overreact to chemical stimuli and replace them with more normal responses, thus lessening and even eliminating the symptoms of MCS.

3. Diagnosis/Tests

3. Diagnosis and Tests

There are currently no laboratory tests available for MCS and it is often unclear whether symptoms are physiologically or psychologically generated. The "gold standard" procedure for diagnosing a MCS patient is to test their response to a random introduction of chemicals the patient has self-identified as problematic.

A diagnosis of MCS can only be justified when the subject cannot consciously distinguish between chemicals and controls, and when responses are consistently present with exposure to chemicals and consistently absent when prompted by a control.

The six point standardised criteria are as follows.

  1. Symptoms are reproducible with repeated (chemical) exposures

  2. The condition has persisted for a significant period of time

  3. Low levels of exposure (lower than previously or commonly tolerated) result in manifestations of the syndrome (i.e. increased sensitivity)

  4. The symptoms improve or resolve completely when the triggering chemicals are removed

  5. Responses often occur to multiple chemically unrelated substances

  6. Symptoms involve multiple-organ symptoms (runny nose, itchy eyes, headache, scratchy throat, ear ache, scalp pain, mental confusion or sleepiness, palpitations of the heart, upset stomach, nausea and/or diarrhea, abdominal cramping, aching joints).

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Do you suffer from MCS? Check out this useful article on various ways to manage sounds, smell and light sensitivities

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