The Health Benefits of Modified Citrus Pectin

Metastasis prevention is a possible benefit, but more research is needed

Modified Citrus Pectin powder and capsules

Verywell / Anastasia Tretiak

Modified citrus pectin (MCP) is a dietary supplement that might help prevent the spread of cancer, lower the risk of heart disease, and treat people with certain types of heavy metal poisoning. Unlike normal pectin, which is not digestible, MCP is chemically altered so that is more readily absorbed in the gut. Once in the bloodstream, MCP is believed to have biological properties beneficial to human health.

While MPC's use in medicine is still highly experimental and its benefits are not yet proven, scientists have begun exploring its use in post-treatment adjuvant therapies to reduce the risk of metastasis (the spread of cancer beyond the original tumor).

Health Benefits

Pectin is a gelatinous substance obtained from pears, apples, guavas, quince, plums, gooseberries, oranges, and other citrus fruits that are commonly used to make jellies and jams. It is a type of carbohydrate, called a polysaccharide, that is composed of between 300 and 1,000 smaller monosaccharides.

By exposing pectin to sodium hydroxide and hydrochloric acid—as is done to create MCP—the polysaccharide molecules can be broken down into smaller units that can pass more readily through the walls of the intestines. Once in circulation, MCP can bind to other substances, including heavy metals and a type of protein associated with atherosclerosis and cancer metastasis.

Whether these effects are robust enough to treat heavy metal poisoning, prevent metastasis, or lower the risk of heart disease has yet to be proven. Although some of the early evidence is promising, scientists have a long way to go before MCP can be considered a viable complementary treatment for any medical condition.

Lead Poisoning

Some scientists believe that modified citrus pectin is a potent chelating agent, meaning that it can bind to metals circulating in the bloodstream and remove them from the body in urine and stool. This can be extremely beneficial for people with lead, mercury, arsenic, or cadmium poisoning in whom the metals can accumulate in tissues and cause serious medical complications.

One of the key studies providing evidence of this effect was published in Alternative Therapies in Health and Medicine in 2008. The study involved seven children with lead toxicity who were given a 5-gram (g) dose of MCP thrice daily until such time as their lead levels fell below an acceptable threshold of 20 micrograms per liter (mcg/L).

According to the researchers, two children reached an acceptable level in two weeks, three children reached it in three weeks, and four reached it by four weeks.

Despite the positive findings, the variability in clearance times has led some scientists to question the effectiveness of MCP given that the half-life of lead in blood without treatment is around 28 days. There is also no evidence that MCP can chelate lead from tissues.

At present, there is no clear proof that MCP can either treat heavy metal poisoning or prevent poisoning in communities at risk.

Metastatic Cancer

Some scientists believe that MCP can reduce the risk of metastasis by binding to galectin-3. This protein plays an important role in cell-to-cell adhesion and is believed to contribute to metastasis by acting as "glue" that sticks circulating cancer cells to distant organs and tissues.

By binding to galectin-3 and essentially taking it out of commission, MCP may reduce cancer's ability to stick to more cells and establish tumors in other parts of the body.

A number of animal and lab studies have looked into the benefit of MCP in preventing metastasis after primary treatment for cancers including breast cancer, skin cancer, colon cancer, and liver cancer. The most advanced stages of research, however, involve prostate cancer.

A 2019 study published in the Journal of Clinical Oncology examined the effect of MCP in 53 men who were treated with either radiation or surgery following a relapse of prostate cancer. Each was given a thrice-daily, 4.8-milligram (mg) dose of MCP for six months.

The response to treatment was measured a prostate-specific antigen doubling time (PSADT) blood test. By definition, a slower doubling time confers to a slower progression of disease and a lower risk of metastasis.

At the end of the phase 2 trial, 70% of the men had an improvement in their PSADT values, while 20% had signs of disease progression.

While the researchers concluded that MCP offers "potential benefits" in reducing the risk of metastasis, stronger evidence is needed before MCP can be considered a viable tool in adjuvant therapy.


A 2013 study in Glycobiology also revealed that galectin-3 plays a role in the development of atherosclerosis, often called "hardening of arteries."

According to the researchers, mice fed a high-cholesterol diet supplemented with MCP had 57% less plaque in the thoracic aorta and 50% less plaque in the aortic arch than mice that did not receive MCP. Interestingly, MCP had no effect on cholesterol levels.

The findings demonstrate galectin-3's role in "sticking" fat cells to the walls of arteries. By binding to galectin-3 and blocking its adhesive properties, MCP may help complement the statin and fibrate drugs commonly used to prevent or treat atherosclerosis. Further human research is needed.

Possible Side Effects

Modified citrus pectin is Generally Regarded as Safe (GRAS) by the U.S. Food and Drug Administration (FDA). Clinical studies have reported only mild side effects, including bloating, gas, and loose stools.

Pectin allergy is not very common but may occur in people who are allergic to cashews and pistachios. Tingling lips, itchy mouth and throat, gastrointestinal upset, and mild asthma-like symptoms have been known to occur. People with tree nut allergies should use MCP with caution.

Due to the lack of safety research, MCP is not recommended in pregnant or breastfeeding women. Its safety in children has also not been established.


Like regular pectin, there is some concern that MCP can bind to certain medications and slow their absorption in the intestine. The possible drug-drug interactions may include:

  • Lanoxin (digoxin) used to treat heart rhythm disorders
  • Mevacor (lovastatin) used to treat high cholesterol
  • Tetracycline antibiotics like Declomycin (demeclocycline) and Minocin (minocycline)

Separating doses by one to four hours can usually prevent drug interactions. Antibiotics tend to require a longer period of separation from modified citrus pectin.

To avoid interactions, always advise your doctor about any medications you are taking, whether they are prescription, over-the-counter, nutritional, herbal, or recreational.

Modified citrus pectin powder

Verywell / Anastasia Tretiak

Dosage and Preparations

Widely available for purchase online, modified citrus pectin can also be found in many natural foods stores, drugstores, and shops specializing in dietary supplements.

MCP is usually sold in capsule and powder forms. Capsule doses range from 650 to 1,000 mg. MCP powders are typically mixed with water or juice, with one teaspoon roughly equalling 5 g.

There are no guidelines for the appropriate use of MCP, although studies have shown it to be safe at doses of up to 15 g per day (usually in three divided doses). MCP can be taken with or without food.

As with any supplement, it is better to start with smaller doses and gradually increase the amount as tolerated. As a general rule, never exceed the recommended dose on the product label.

Modified citrus pectin should be stored in a cool, dry place after opening. Never use a supplement past its expiration date.

What to Look For

The FDA does not strictly regulate dietary supplements. As such, there is no guarantee of the strength, purity, or safety of these products.

To better ensure quality, opt for brands that have been voluntarily submitted for testing by an independent certifying body like the U.S. Pharmacopeia (USP), ConsumerLab, or NSF International. Certification ensures that the ingredients and ingredient amounts are the same as on the product label and that no other impurities have been found.

Always check the product label for added ingredients you may be sensitive to, like gluten or preservatives. Generally speaking, MCP powders should be pure with no other added ingredients.

Other Questions

Some MCP products are labeled "fractionated." What does that mean?
Fractionated is simply another way of saying that polysaccharide molecules have been broken down. What that term doesn't tell you is how much the molecules have been broken down, and that can be a problem.

MCP is not a defined term, and some experts warn that not all MCP products are created equal. Some products labeled "modified" may not have undergone the same depolymerization process as others and end up having larger molecules unable to pass through the intestinal wall.

While this may be difficult to ascertain on the product label, some brands will list the molecular size (ideally below 13 kDA) as well the esterification molecular composition (ideally under 5%). These are likely the most trustworthy products to buy.

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Article Sources
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  1. Fracasso AF, Perusello CA, Carpiné D, et al. Chemical modification of citrus pectin: Structural, physical and rheologial implications. Int J Biol Macromol. 2018 Apr;109(1):784-92. doi:10.1016/j.ijbiomac.2017.11.060

  2. Eliaz, I. Letter to the Editor: Not all modified citrus pectins are the same: size does matter. Am J Physiol Heart Circ Physiol. 2019 May;316(5):H1232-H1233. doi:10.1152/ajpheart.00118.2019

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