Evidence-based·Last reviewed May 30, 2026·How we grade evidence

Citrus Bioflavonoids

PhytochemicalBest with a meal

Useful mainly for people with chronic venous insufficiency using a diosmin + hesperidin formulation.

Quick decision guide

May help most

People with chronic venous insufficiency using a diosmin + hesperidin formulation

Common dosing range

500–1,000 mg/day, often with 500–1,000 mg vitamin C

When to expect effects

Weeks

Watch out for

Generic 'citrus bioflavonoids' blends vary widely in composition; grapefruit-derived products can inhibit CYP3A4

What is it

Citrus bioflavonoids are a mix of flavanones (hesperidin, naringin, eriocitrin) and flavones (diosmin, nobiletin) extracted from citrus fruit peels and pith. Older literature referred to them collectively as 'vitamin P,' a designation no longer recognized.

Is it worth it for you?

Use this as a quick fit check, not a diagnosis.

Worth considering if…

You have diagnosed chronic venous insufficiency and are using a diosmin+hesperidin formulation
You experience easy bruising or capillary fragility and want a low-risk adjunct to adequate vitamin C

Probably skip if…

You are using a generic, non-standardized 'citrus bioflavonoids' blend without knowing the specific compounds
You take medications with grapefruit warnings and are using naringin-containing extracts
You expect benefits equivalent to specific clinical-grade diosmin preparations from a generic OTC blend

Evidence at a glance

chronic venous insufficiency

Good Evidence
Effect
Significant reductions in leg swelling, heaviness, and pain compared to placebo in multiple RCTs
Best fit
Adults with chronic venous insufficiency, leg edema, and varicose vein symptoms
Time
4–8 weeks

Evidence for 1 use

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

chronic venous insufficiency

Disease adjunct
Good Evidence

A specific micronized purified flavonoid fraction (MPFF, containing 90% diosmin + 10% hesperidin) has been studied in multiple well-designed RCTs demonstrating reduced leg volume, symptom improvement, and healing of venous leg ulcers. This evidence applies to the specific pharmaceutical-grade formulation, not generic bioflavonoid blends.

Effect size
Significant reductions in leg swelling, heaviness, and pain compared to placebo in multiple RCTs
Time to effect
4–8 weeks
Best fit
Adults with chronic venous insufficiency, leg edema, and varicose vein symptoms
Less likely
People with leg swelling from cardiac or renal causes

Bottom line: Diosmin-based formulations have strong RCT evidence for chronic venous insufficiency symptoms; generic blends have not been tested to the same standard.

SourceCesarone et al., 2005 — PubMed

How it works

Citrus bioflavonoids stabilize capillaries by inhibiting hyaluronidase and reducing capillary leakage, improve venous tone, and have antioxidant and mild anti-inflammatory effects. They were originally proposed by Albert Szent-Gyorgyi alongside vitamin C. Modern evidence supports specific uses (e.g., hesperidin+diosmin for venous insufficiency), but generic 'citrus bioflavonoids' products vary widely in composition.

How to take it

1. Typical dose
500–1,000 mg/day of standardized flavonoid fraction (e.g., 450 mg diosmin + 50 mg hesperidin per 500 mg dose)
2. Timing
With meals
3. With food
With food — absorption is improved with food and gut microbiota processing of flavonoids
4. How long to try
4–8 weeks to assess venous symptoms; ongoing if benefit confirmed

What to track

Leg swelling and heaviness if using for venous insufficiency
Easy bruising frequency
Any signs of drug interaction if on CYP3A4-metabolized medications

2 commercial forms

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

Generic citrus bioflavonoid blend

Cheap ingredient, mixed evidence.

Composition varies; standardization may be limited.

Standardized MPFF or pure hesperidin

Better evidence base.

Defined dose enables clinical use.

Safety

Know the common side effects, key cautions, and who should avoid it.

Common side effects

Mild GI upsetHeadache (uncommon)

Who should avoid it

  • People on CYP3A4-metabolized medications if using grapefruit-derived naringin products

Pregnancy & breastfeeding

Citrus bioflavonoids from food sources are safe; high-dose supplements in pregnancy have not been well studied — consult a clinician.

Interactions

Statins (simvastatin, lovastatin)Moderate

Naringin from grapefruit-source extracts inhibits CYP3A4 and can elevate statin blood levels

Calcium channel blockers (felodipine, etc.)Moderate

CYP3A4 inhibition by grapefruit-derived naringin may increase drug levels

Immunosuppressants (cyclosporine)Moderate

CYP3A4 inhibition may significantly raise cyclosporine levels — avoid grapefruit-derived forms

Food sources

Orange (medium)

Amount
~50 mg hesperidin
%DV
—

Lemon

Amount
~30 mg flavanones
%DV
—

Grapefruit (half)

Amount
~30 mg naringin
%DV
—

Choosing a product

What to look for on the label — and what to be skeptical of.

Look for…

Specific compound identified (diosmin, hesperidin, or MPFF)
Dose of each flavonoid per serving specified
Grapefruit-free labeling if on CYP3A4-sensitive medications
Pharmaceutical-grade or standardized extract for venous insufficiency use

Be skeptical of…

'Vitamin P' (an obsolete, non-recognized designation)
'Cures varicose veins'
Generic 'bioflavonoid complex' without specifying compounds and doses

Frequently asked questions

Are citrus bioflavonoids vitamin P?⌄

Older terminology. Modern nutrition does not classify them as vitamins.

Do bioflavonoids help vitamin C work better?⌄

Some recycling effects exist in vitro, but the practical benefit of combining them in supplements is modest.

References by claim

chronic venous insufficiency

Cesarone et al., 2005 — PubMed (2005) link

Track Citrus Bioflavonoids with Pilora

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Evidence-based·Last reviewed May 30, 2026·Evidence current as of May 30, 2026·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.