Modified Citrus Pectin

MCP · Citrus pectin · Pectasol

Snapshot

Indications	Contraindications
Prostate-specific antigen doubling time^1–3 Lead excretion⁴ Toxic metal excretion⁵ Fecal uranium excretion⁶	Pregnancy or nursing⁷ Diabetes or intestinal disorder⁷

Modified citrus pectin (MCP) is citrus pectin processed to a lower molecular weight, and it acts as a competitive antagonist of galectin-3². It is used for two things that follow from that profile.² Men with biochemically relapsed prostate cancer after local therapy take it to lengthen prostate-specific antigen (PSA) doubling time^{1, 2}, and people with metal exposure take it to increase excretion of lead, arsenic, and cadmium.

The prostate evidence comes from single-arm phase 2 studies that reported improved PSA doubling time without grade 3 or 4 toxicity^{2, 3}. The metal data come from small pilot studies measuring excretion, and a placebo-controlled trial in knee osteoarthritis found no significant benefit over placebo. In obese rats with myocardial ischemia, a 2025 study found MCP reduced expression of fibrosis-related genes through galectin-3 inhibition; no human trial has tested it. Many products list modified citrus pectin, mostly as capsules and powders; see Form comparison.

United States product labels carry two kinds of caution: some say not to take it when pregnant or nursing⁷, and others direct people with diabetes or an intestinal disorder to consult a health care professional first⁷.

Last updated October 15, 2026. Read how we make monographs.

In the full monograph

33 sources, 20 studies

When to useThe situations practitioners use it for, each with the reason and the study behind it.
SafetyWho should avoid it, who needs extra care, and the side effects reported in studies.
InteractionsThe medicines and supplements it interacts with, the effect of each, and what labeling says to watch.
Protocol notesThe doses used in studies, how and when they were taken, and how the forms on the market compare.
How it worksWhat it is and how it works in the body, in plain terms.
Published studiesThe studies behind each use, popular claims checked against them, and trials still under way.
Word of mouthWhat patients and practitioners report online, kept separate from the clinical evidence.
Clinical perspectiveA closing read of where the evidence is solid, where it is thin, and what has not been studied.

Snapshot

In the full monograph

Sources