What Is Homeopathy?

Learn the difference between homeopathic remedies and conventional medicine

Homeopathy, also called homeopathic medicine, is a form of complementary and alternative medicine (CAM) that uses very small amounts of natural substances that, at higher amounts, may cause a disease or symptom.

This article explores the theory and history behind homeopathy, what scientific studies say about homeopathic remedies, how they compare with conventional medicine, and the possible side effects and risks.

Various herbs and oils in bottles and bowls with a mortar and pestle on a table
JanPietruszka / iStock

Homeopathy: Theories and Principles

Homeopathy is based on two theories and three principles.

Theory 1: Like Cures Like

The main theory behind homeopathic medicine is simple: “like cures like.”

The belief is that if something causes symptoms in a healthy person, it may cure those same symptoms in a person with an illness. For example, if you have insomnia, a homeopathic remedy may be a very weak solution containing coffee.

Homeopathy practitioners say it works because a small amount of the disease-causing substance stimulates your body to heal itself.

While homeopathy is largely unproven, the basic idea isn’t foreign to modern medical science. It’s essentially how vaccines work—they expose you to a small amount of a dead or inactivated germ, and that teaches your immune system how to recognize and destroy it, protecting you from the disease.

Theory 2: Potentization

The other theory underlying homeopathy is that of potentization. Practitioners believe the more an ingredient is diluted, the more potent it becomes.

The thought is that diluting and agitating (vigorously shaking) an ingredient activates its curative powers and enhances its effect. Potency in homeopathic solutions is indicated in three ways:

  • X or D (the decimal dilution scale): An ingredient is mixed with alcohol or distilled water at a ratio of 1:10. For example, one part coffee (or other curative ingredient) to ten parts water.
  • C (the centesimal dilution scale): 1:100 ratio, or one part curative ingredient to 100 parts water/alcohol.
  • Q (the quinquagintimillesimal scale): 1:50,000 ratio, or one part curative ingredient to 50,000 parts water/alcohol.

These dilutions may happen several times before a homeopathic remedy is given. For example, a 3C solution is diluted on the C scale (1:100) one time, then shaken up. Then it’s diluted (1:100) a second time and shaken, then a third time. The resulting solution has only molecules of the original ingredient left.

Skeptics have described this as the equivalent of dissolving one Advil (ibuprofen) in the ocean and then drinking a few drops.

In response, some homeopaths claim the amount of the ingredient itself isn’t what’s important, but rather the energetics of the ingredient—which they say the dilution process activates to initiate a therapeutic effect on the body.

Three Principles

Homeopathy is based on three principles:

  1. The law of similars: The “like cures like” theory.
  2. The principle of the single remedy: One remedy should cover all the physical, emotional, and mental symptoms of an illness.
  3. The principle of the minimum dose: Only a small amount of substance is first used at first, followed by minuscule increases over time.

History of Homeopathy

Homeopathy was developed by a German healthcare provider Samuel Hahnemann in the late 1700s and early 1800s.

It started when he treated himself with a small amount of cinchona tree bark, which contains the malaria treatment quinine. It produced the symptoms of malaria without the consequences (anemia and jaundice from loss of white blood cells). That’s when he came up with the theory of like cures like.

The method became rather popular for a time, eventually developing more than 2,000 homeopathic remedies. The use of homeopathy has fallen off with the advent of newer and better modern treatments, but it’s still used today.

Homeopaths and medical doctors existed quite separately for the first century. By then, however, homeopaths had adopted some more conventional methods, and medical doctors had adopted some homeopathic treatments.

In 1903, the American Medical Association invited homeopaths to become a part of the organization.

Research Into Homeopathy

Results on the effectiveness of homeopathic remedies have been inconsistent, primarily due to the lack of widespread regulations of the practice. This makes the dosage of homeopathic medicines variable.

A 2016 review evaluated the body of research on homeopathic remedies. The authors concluded individualized homeopathy (based on the specific needs of the person) “may have small, specific, treatment effects.” 

By contrast, a 2017 meta-analysis found there was no single clinical medical condition for which there is reliable evidence that homeopathy is effective.

And a large 2018 review looked at the common claims that homeopathic medicines can prevent or treat respiratory tract infections in children. The authors said they found no evidence these treatments work. Due to lack of detailed reporting in earlier studies, they couldn’t draw conclusions about their safety.

It’s likely that future studies will shine more light on the safety and effectiveness of homeopathic remedies.

Homeopathy and Cancer

For cancer, animal studies suggest homeopathic remedies—when used along with conventional treatments—may inhibit cancer’s growth, reduce symptoms, and improve ​quality of life.

At the current time, however, experts can say whether the results can be applied to humans, so more work is needed.

A 2018 study in an integrative cancer treatment program looked at homeopathy for symptom management. Of 124 patients, 73% said homeopathic remedies were beneficial. Those most likely to benefit were:

Homeopathy Use in People With Cancer

A study looking at CAM treatments among people with cancer found that homeopathy was the second most popular type, used by 39% of study participants. Most of them used homeopathic treatments to counter the side effects of chemotherapy and radiation.

Finding Homeopathic Remedies

You can buy some homeopathic medications at health food stores.

Others are only available through qualified homeopathic practitioners or integrative medicine specialists, such as naturopathic healthcare providers.

Homeopathy Side Effects and Safety

Homeopathic remedies are generally pretty safe and without significant side effects, since they use only a small amount of a highly diluted substance.

However, if you’re pregnant, breastfeeding, or being treated for a serious medical condition, talk to your healthcare provider before using these remedies or any other form of alternative medical care.

The Danger of Homeopathy

It’s important to understand homeopathic remedies should not replace conventional treatments for most medical conditions. There’s no evidence these substances have any effect.

If you use homeopathic remedies instead of conventional treatments backed by well-designed studies, you may end up sicker and worse off than you were from just the disease.

While many of these treatments are unlikely to be harmful when combined with conventional treatments, be sure to talk to your healthcare provider about them to make sure you’re staying safe.

Homeopathy vs. Conventional Medicine

Homeopathic medicine and allopathic (mainstream or conventional) medicine are essentially opposites, with homeopaths using the like-cures-like approach and medical practitioners using treatments that produce a different effect than the disease.

But that doesn’t mean they can’t work together. A relatively new approach has been using a combination of conventional therapies along with alternative practices to help control symptoms. This is now referred to as integrative medicine.

What Homeopathy Does Better Than Conventional Medicine

While homeopathic remedies haven’t conclusively been found helpful for any disease, practitioners do offer a service some people feel is currently lacking in conventional medical care: time and listening.

A visit with a homeopathic provider may last for an hour or more, compared with the brief visits many allopathic healthcare providers offer. The opportunity to have someone listen to concerns in an empathic manner can be important.

Homeopathic providers may also take more time to discuss healthy lifestyle practices, which can have a real benefit on health.


Homeopathy is a form of CAM that uses tiny amounts of substances that, in larger amounts, cause symptoms in order to treat those symptoms. The theory is called “like cures like.”

Homeopathic practitioners believe greatly diluting and shaking a substance can activate its curative abilities. They seek a single remedy for all aspects of an illness and use the smallest dose possible.

Homeopathy has been around for more than 200 years and involves some 2,000 remedies. While research has yet to prove they’re effective, they’re being used alongside mainstream medicine more and more, especially for symptom management.

While homeopathy isn’t generally harmful, it could cause you to delay proper diagnosis and treatment, allowing your condition to get worse. It’s best used to enhance, not replace, conventional medicine.

Frequently Asked Questions

  • Do homeopathic remedies have side effects?

    Not typically. Homeopathic treatments are highly diluted substances and are not likely to cause any side effects.

  • What conditions can homeopathy treat?

    Scientific evidence is lacking, but homeopathic practitioners say these remedies can treat many conditions, including: 

    • Allergies
    • Arthritis
    • Cold
    • Cough
    • Diarrhea
    • Flu
    • Gastritis
    • Menstrual cramps
    • Muscle aches
    • Pain
    • Stress
    • Stomach aches
    • Teething

    Homeopathy is best used alongside conventional medicine with your healthcare provider's knowledge.

  • Is there any danger in using homeopathy?

    Homeopathic medicines are generally safe. The primary danger is that you may put off seeing a mainstream healthcare provider in favor of using homeopathic remedies. This could allow a serious condition to go undiagnosed and untreated. 

7 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. Loudon I. A brief history of homeopathyJ R Soc Med. 2006;99(12):607-610. doi:10.1258/jrsm.99.12.607

  2. Mathie RT, Van Wassenhoven M, Jacobs J, et al. Model validity and risk of bias in randomised placebo-controlled trials of individualised homeopathic treatment. Complement Ther Med. 2016;25:120-125. doi:10.1016/j.ctim.2016.01.005

  3. Mathie RT, Ramparsad N, Legg LA, et al. Randomised, double-blind, placebo-controlled trials of non-individualised homeopathic treatment: systematic review and meta-analysis. Syst Rev. 2017;6(1):63. doi:10.1186/s13643-017-0445-3

  4. Hawke K, van Driel ML, Buffington BJ, McGuire TM, King D. Homeopathic medicinal products for preventing and treating acute respiratory tract infections in children. Cochrane Database Syst Rev. 2018;9(9):CD005974. doi:10.1002/14651858.CD005974.pub5

  5. Frenkel M. Is there a role for homeopathy in cancer care? questions and challenges. Curr Oncol Rep. 2015;17(9):43. doi:10.1007/s11912-015-0467-8

  6. Samuels N, Freed Y, Weitzen R, et al. Feasibility of homeopathic treatment for symptom reduction in an integrative oncology service. Integr Cancer Ther. 2018;17(2):486-492. doi:10.1177/1534735417736133

  7. Gras M, Vallard A, Brosse C, et al. Use of complementary and alternative medicines among cancer patients: A single-center study. Oncology. 2019;97(1):18-25. doi:10.1159/000499629

By Lynne Eldridge, MD
 Lynne Eldrige, MD, is a lung cancer physician, patient advocate, and award-winning author of "Avoiding Cancer One Day at a Time."