Gerson therapy

Gerson therapy involves a specific organic vegetarian diet with nutritional supplements and enemas. There is no scientific evidence to use it as a treatment for cancer.


  • Gerson therapy uses a specific organic vegetarian diet, nutritional supplements and enemas to treat cancer
  • There is no scientific evidence that it can treat cancer or its symptoms
  • Gerson therapy can have severe side effects

What is Gerson therapy?

A German doctor called Max Gerson developed Gerson therapy in the 1920s and 30s. He claimed that it helped cure his migraine headaches. So, he went on to use it to treat other diseases such as tuberculosis and cancer.

You might also hear Gerson therapy called the:

  • Gerson diet
  • Gerson regimen
  • Gerson method

Followers believe that changes to diet and nutrient intake can help to treat cancer. They also think that cancer is a symptom of disease of the whole body. 

It aims to rid the body of toxins and strengthen the body’s immune system. This way supporters say it can bring the body back to its normal metabolic state, and the body can heal itself.

The Gerson regime has 3 main parts:

  • a strict organic vegetarian diet made up of fruit and vegetables high in potassium and low in sodium
  • vitamin and mineral supplements, and specific enzymes
  • coffee or castor oil enemas

Gerson therapists believe that people with cancer have too much salt (sodium) in their bodies. This is compared to the amount of potassium.

People following the therapy only eat organic, vegetarian food. This includes up to 13 glasses of fresh juices a day. It is believed that by doing so, it will restore the right balance. And that it will cleanse the liver. 

Up to 5 coffee enemas a day are also given. It is believed that coffee enemas further help to excrete toxins from the liver and colon. And that taking certain supplements and enzymes help the body to get rid of cancer cells.

Scientific research does not support any of these claims.

Why people with cancer use it

Your doctor may have told you that conventional treatments cannot cure your cancer. This can be tough to accept.

In this situation, many people look for alternative therapies, including diets such as Gerson. But there is no scientific evidence that the Gerson diet works. It may cause serious health problems and make you feel worse.

The Gerson Research Organisation published a study in 1995. It looked at people with melanoma skin cancer who were doing the Gerson regime. It found that people on the diet had higher survival rates. This was when compared to rates that were published in other scientific studies.  

But a review study in 2014 found that the 1995 research was not accurate. It also did not use a single classification of tumour staging. Tumour staging means the size of a cancer and how far it has spread. The researchers said that they couldn’t say whether the Gerson regime worked.

Gerson therapy is popular with many people who have advanced cancer. But we need more scientific research before it can be used as a treatment for cancer.

Diet may play an essential role in helping to prevent cancer. But there is no current evidence to say that drastic diet changes will kill cancer cells.

Talk to your doctor before making any decisions about following an alternative diet.

Some people use alternative or complementary therapy to feel more in control of their cancer and its treatment.

Some people believe that Gerson therapy boosts their immune system. By doing so, it helps to fight their cancer.

There is no scientific evidence to prove this, partly because of lack of research. We, need more research to have proof. Only then can we say with certainty that Gerson therapy affects the immune system.

How you have it

The Gerson diet is a strict low salt, organic fruit and vegetable diet.

Each day you will need to:

  • drink 20 pounds (about 9 kilos) of crushed fruit and vegetables (one glass of juice hourly, 13 times each day)
  • have up to 5 coffee enemas and perhaps also castor oil enemas
  • take potassium and other supplements, including vitamin B12, pancreatic enzymes and thyroid supplements

You can have Gerson therapy by staying in a clinic, or you can do it yourself at home.

The Gerson Institute refers people to clinics licensed by them. Their most popular one is in Mexico and there is also one in Hungary.

Gerson therapists advertise their clinics as very safe, relaxing and caring. But it is worth finding out if they have the medical facilities needed if any emergencies arise.

People who go to these clinics sometimes say that they feel better psychologically. These places might be very relaxing and caring places to be. But the possible side effects of Gerson therapy are a cause of concern.

You might stay at the clinic for a couple of weeks and then go home to continue the treatment. Or you can order a home therapy deal on the internet.

Treatment can continue for a few months to a few years. Having this therapy at home takes a great deal of time, energy and commitment. It can be almost a full-time job.

Side effects

In some situations, the Gerson diet can cause severe side effects. Some are potentially harmful. Speak to your doctor first if you are thinking of using the Gerson diet.

Coffee enemas remove a lot of potassium from your body and have been known to cause:

  • infections
  • dehydration
  • fits
  • salt and other mineral imbalances in the body
  • heart and lung problems, even death
  • constipation and inflammation of the bowel (colitis) from regular, long term use of enemas which can weaken the bowel muscle

Other reported side effects include:

  • loss of appetite
  • diarrhoea and sickness
  • abdominal cramps
  • aching, fever and sweating
  • cold sores
  • dizziness and weakness

Research into Gerson therapy for cancer

There is no evidence to prove that Gerson therapy works as a cure for cancer. We need more research to compare it with accepted and proven treatments within properly organised clinical trials.

The National Cancer Institute in the USA did a review in 2010. They found no evidence that it helped people with cancer.

Researchers in the UK did a study of 6 patients in 2007. They found that this type of therapy seemed to help people feel better emotionally. It also reduced their need for painkillers. But this number of patients is very small, so these findings are not reliable. The researchers suggested that a clinical trial is necessary. This way it will be possible to see if Gerson therapy works as a cancer treatment.

A review study in 2014 looked at 13 different cancer diets. The researchers looked at all the previous research on Gerson therapy. They found that none of the previous reports on Gerson therapy proved that it was effective.

A study looked at the 5-year survival rate of 153 cancer patients. They found that there were higher survival rates in patients with melanoma, ovarian and colorectal cancer, who were undergoing Gerson therapy. This was compared to patients having other therapies. However, this study was done by the Gerson Research Organisation. The method they used is not reliable and flawed. A further review found the evidence and study unreliable. 

It is difficult to be sure if there is any benefit in using Gerson therapy from the research so far.

This is because:

  • record keeping during studies has been quite poor
  • it is a complex therapy that can go on over months or years
  • we can’t know what other factors might or might not affect the outcome during this time, including the environment or other treatments and diets
  • some promoters give only anecdotal evidence, meaning that they use an example of an occasional person getting better as evidence

How much it costs

Gerson therapy can be costly. Do consider the ongoing cost of the treatment before you start.

You will need to buy special equipment if you are thinking of having Gerson therapy at home. Buying organic fruit, vegetables, coffee and supplements will also be an ongoing cost.

You will have to pay for flights and accommodation if you are going to a special clinic in another country. This will be on top of the treatment. Depending on the treatments involved, the cost can be thousands of pounds.

A word of caution

Some elements of the Gerson diet are healthy. For example, eating low fat food and lots of fresh fruit and vegetables.

But it is not healthy if you are eating vast quantities of one food group in a certain way (juicing) without balancing it with other food groups. It can be harmful to people who are already weak and ill. There are also many possible side effects some of which can be severe.

Most Gerson therapists encourage people not to have chemotherapy while having their therapy. This is because they believe that chemotherapy damages immunity. They say that radiotherapy is more compatible with Gerson treatment.

It is up to you to decide whether you want to use any alternative therapy. Stopping your conventional cancer treatments and methods of symptom control can be harmful.

Talk to your specialist about any alternative or complementary therapies that you want to try. Find out all you can about the therapy before deciding to use it.

Many websites are advertising or promoting Gerson therapy. But reputable scientific cancer organisations do not support them. Do not believe information or pay for alternative cancer therapy over the internet.

  • Gerson regimen

    B Cassileth

    Oncology (Williston Park). February, 2010. Vol 24, (2):201.

  • Surviving Against All Odds: Analysis of 6 Case Studies of Patients With Cancer Who Followed the Gerson Therapy

    A Molassiotis and others

    Integrative Cancer Therapies, March, 2007. Vol 6, (1), 80-88.  

  • Counseling patients on cancer diets: a review of the literature and recommendations for clinical practice.

    J Huebner and others

    Anticancer Research. 2014 January; 34(1):39-48.

  • The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. If you need additional references for this information please contact with details of the particular issue you are interested in.

Last reviewed: 
11 Oct 2022
Next review due: 
11 Oct 2025

Related links