What Is Gerson Therapy & Does It Actually Work?

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Gerson therapy, also called Gerson diet, Gerson regimen, and Gerson method, was developed by German doctor Max Gerson in the 1920s and 1930s. First developed to treat his migraines, Gerson adapted his plan to address tuberculosis and later other conditions, including cancer.

Gerson therapy involves a strict and specific organic diet, nutritional supplements, and the use of enemas.


Gerson therapy is not backed by evidence and is recommended against by major health institutions such as the American Cancer Society.

There is no scientific evidence to support the use of Gerson therapy in the treatment of cancer or any other condition. It is not approved by the Food and Drug Administration (FDA). Credible cancer and medical associations recommend against its use.

Person drinking a fruit juice mixture from a blending container

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Gerson therapy should never be used as a substitute for genuine treatments such as surgery, radiation therapy, or chemotherapy. In addition to being unproven, Gerson therapy can be harmful.

This article will discuss the theory behind Gerson therapy, what it entails, and why it isn't a viable treatment for cancer and other conditions.

Core Principles

Gerson therapy proposes that people with cancer have too much sodium in their bodies compared to potassium and that a buildup of toxins in the body causes changes in cell metabolism, leading to cancer.

The goal of Gerson therapy is to "detoxify" the body and stimulate metabolism so that the body can heal itself. Gerson's theories and principles are not backed by science or credible evidence.


Gerson therapy is comprised of three main parts:

  • A strict diet
  • Supplements
  • Enemas


Followers of Gerson therapy must adhere to a strict low-sodium, organic fruit and vegetable diet. While a diet with limited sodium and plenty of fruit and vegetables is usually healthy, the diet involved with Gerson therapy is taken to an extreme.

Gerson therapy requires the regime be strictly followed, including a diet consisting of:

  • Drinking juice freshly made from organic fruit and vegetables (one glass an hour, 13 times a day)
  • Vegetarian meals of organically grown fruit and vegetables that are low in sodium and high in potassium, and whole grains
  • No salt, spices, or oils used in the food

Food must be prepared without using aluminum cookware or utensils.


Gerson therapy requires taking over nine specific supplements, including vitamins, minerals, and enzymes.


People following Gerson therapy receive three to five coffee enemas (injecting coffee into the rectum and colon by way of the anus) per day. Castor oil enemas and/or chamomile enemas may also be administered.

Coffee enemas have not been shown to have health benefits and can pose a safety risk.


While advocates for Gerson therapy claim it boosts the immune system, no scientific evidence shows this to be true. Gerson therapy as a whole has not been shown to have health benefits.

Some aspects of Gerson therapy can be healthy when used within reason. For example, eating lots of fresh fruit and vegetables is nutritious.

But eating vast quantities of one food group, especially in a certain way (such as juicing) can be harmful when not balanced with other food groups. This especially is a risk for people who are already ill and weak, such as people living with cancer.

Reputable scientific cancer organizations do not recommend Gerson therapy. Be skeptical of advertisements and programs that claim to have the support of cancer organizations.


One significant risk related to Gerson therapy is that most Gerson therapists advise people not to have chemotherapy. Stopping or avoiding conventional cancer treatments can cause harm and affect your treatment outcomes. Always discuss potential alternative or complementary therapies with your healthcare specialist before trying them.

Gerson therapy itself can have negative, potentially harmful effects, including:

  • Coffee enemas remove a lot of potassium from the body. Repeated use of coffee enemas can cause electrolyte imbalances and impaired nutrient absorption.
  • Too many enemas of any kind can disrupt naturally occurring chemicals in the body that keep the muscles, heart, and other organs working properly.
  • Regular enemas can also cause injury to the anus and rectum.

Coffee enemas have been known to cause:

  • Infections
  • Dehydration
  • Seizures
  • Imbalances of salt and other minerals in the body
  • Cardio (heart) and respiratory (lung) problems
  • Constipation
  • Colitis (inflammation of the bowel) from weakened bowel muscle due to regular, long-term use of enemas
  • Death

Other reported side effects include:

  • Loss of appetite
  • Diarrhea
  • Vomiting
  • Abdominal cramps
  • Aching
  • Fever and sweating
  • Cold sores
  • Dizziness and weakness

Metabolic diets like Gerson therapy can cause nutrient deficiencies such as calcium, vitamins D and B12, and protein. Anemia and malabsorption in the intestine can also occur.

With Gerson therapy, fruit and vegetables are eaten raw, which can make them harder to absorb. This is particularly true for people with gastrointestinal cancers or gastrointestinal disorders induced by chemotherapy.

People with cancer often experience weight loss due to protein-calorie malnutrition. Adequate calorie and nutrient intake are essential.

Along with eating a wide variety of fruit and vegetables, people with cancer are generally advised to follow a diet that is high in calories and high in protein, low in saturated fats, but high in monounsaturated fats. A wide variety of protein sources is also encouraged.

The diet involved with Gerson therapy can disrupt the special nutritional needs of people with cancer and those undergoing cancer treatment.

Side effects of Gerson therapy include:

  • Loss of appetite
  • Flu-like symptoms
  • Weakness, dizziness
  • Perspiration with a foul odor
  • Cold sores/fever blisters
  • High fever
  • Tumor pain
  • Diarrhea and vomiting
  • Intestinal cramping
  • Coma resulting from low sodium levels in the blood (has occurred in a few cases)

Who Should and Should Not Do Gerson Therapy?

Gerson therapy has not been approved by the FDA. It is not recommended as a treatment for cancer or any other disease.

Follow your healthcare provider's guidance for treatment and for dietary recommendations.

For additional information about diet during cancer treatment, you can consult the Cancer Information Service (800-4-CANCER, or 800-422-6237) and the National Cancer Institute site Nutrition in Cancer Care.


Gerson therapy has not been proven effective by any credible studies or research.

The Gerson Research Organisation published a study in 1995 suggesting that people with melanoma skin cancer who were doing Gerson therapy had higher survival rates. A review study in 2014 found this study to be inaccurate and noted that it used poor methodology, including not using a single classification of tumor staging.

A review by the National Cancer Institute in 2010 found no evidence that it helped people with cancer. A review study in 2014 that examined 13 different cancer diets found that none of the previous reports on Gerson therapy proved it to be effective.


Max Gerson developed Gerson therapy in the 1920s and 1930s to address migraines, then tuberculosis. It is now primarily aimed at people with cancer. There is no evidence that it is effective, and it can cause serious harm.

Gerson therapy is not FDA-approved and is recommended against by major cancer and medical organizations. Before trying Gerson therapy, or any alternative or complementary treatment, talk to your healthcare provider or specialist to make sure it is safe for you to try.

Frequently Asked Questions

  • How much does Gerson therapy cost?

    Gerson therapy can be costly because of expenses such as:

    • Buying special equipment
    • Buying organic fruit and vegetables, coffee, and supplements
    • Flights and accommodation (if you are going to a special clinic out of the country)
    • Cost of treatment
  • How long do you have to follow Gerson therapy for it to be effective?

    Gerson therapy can go on for months or years, but there is no credible evidence that it is effective regardless of how long it is followed.

  • What types of foods can you eat during Gerson therapy?

    Gerson therapy involves a strict diet consisting of:

    • Drinking one glass per hour, 13 times a day, of juice freshly made from organic fruits and vegetables
    • Vegetarian meals
    • Organically grown fruits and vegetables that are low in sodium and high in potassium
    • Whole grains
    • No salt, spices, or oils used in the food
    • Food prepared without using aluminum cookware or utensils

    Gerson therapy can cause harmful effects, particularly to those with cancer or who are undergoing cancer treatments. Talk to your healthcare provider before trying Gerson therapy or following this diet.

9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Cancer Council. Is Gerson therapy a good cancer treatment?

  2. National Cancer Institute. Gerson therapy (PDQ®)–patient version.

  3. Cancer Research UK. Gerson therapy.

  4. Memorial Sloan Kettering Cancer Center. Gerson regimen.

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  6. Breastcancer.org. What to know about diets that claim to cure cancer.

  7. Gangadharan A, Choi SE, Hassan A, et al. Protein calorie malnutrition, nutritional intervention and personalized cancer care. Oncotarget. 2017;8(14):24009-24030. doi:10.18632/oncotarget.15103

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  9. Huebner J, Marienfeld S, Abbenhardt C, Ulrich C, Muenstedt K, Micke O, Muecke R, Loeser C. Counseling patients on cancer diets: a review of the literature and recommendations for clinical practice. Anticancer Res. 2014;34(1):39-48.

By Heather Jones
Heather M. Jones is a freelance writer with a strong focus on health, parenting, disability, and feminism.