Grapefruit fiber

PrebioticBest with a meal

What is it

Grapefruit fiber is the dietary fiber fraction (primarily pectin and cellulose) extracted from grapefruit (Citrus paradisi). It is used in supplements, functional foods, and as a thickener.

Evidence for 2 uses

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Cholesterol management

Limited Evidence

Pectin-rich fibers (including grapefruit fiber) have modest LDL-lowering effects.

Bowel regularity / gut health

Limited Evidence

Fiber generally supports bowel regularity and gut microbiome health.

How it works

Grapefruit fiber is rich in pectin, a soluble fiber that forms a viscous gel in the GI tract. The gel slows gastric emptying, modestly attenuates postprandial glucose absorption, and binds bile acids in the small intestine. Bile acid binding can lead to modest cholesterol-lowering effects as the liver uses cholesterol to make new bile acids. In the colon, pectin is well-fermented by gut microbiota, producing short-chain fatty acids that nourish colonocytes and support a healthy microbiome.

Dosage

Typical use: 5-15 g/day. General fiber AI: 25 g/day (women), 38 g/day (men).

When and how to take it

WHEN: Any time of day, often with meals to support glycemic and lipid effects. HOW: Mix into water or food; drink plenty of water.

1 commercial form

Compare the main delivery options and what they’re best suited for.

Grapefruit fiber powder

Concentrated pectin source from grapefruit peel/pulp.

Not absorbed; acts in GI tract

Safety

Generally well tolerated. Excessive intake may cause bloating, gas, or abdominal discomfort. Adequate water intake is important.

Who should be cautious

People with severe GI motility disorders should consult a clinician. Significantly increased fiber should be introduced gradually with adequate water.

Interactions

Grapefruit FIBER does not contain the furanocoumarins that cause grapefruit juice interactions (these are mostly in the juice fraction). However, may modestly reduce absorption of medications taken simultaneously; separate by 1-2 hours.

Food sources

Whole grapefruit

Amount
1/2 medium = 2 g fiber
%DV
7%

Frequently asked questions

Does grapefruit fiber interact with statins like grapefruit juice?⌄

No. The drug-interacting compounds (furanocoumarins) are in the juice, not the fiber. Grapefruit fiber supplements are generally free of these interactions.

Will grapefruit fiber help me lose weight?⌄

It may modestly support satiety, but supplemental fiber alone has small effects on weight.

References

Grapefruit fiber on NIH DSLD (US supplement label database) — NIH Dietary Supplement Label Database link

Research on Grapefruit fiber (PubMed search) — PubMed link

Track Grapefruit fiber with Pilora

Set up dose reminders, check interactions, and join the community in the Pilora iPhone app.

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Evidence-based·How we grade evidence

Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.