PlainVitamins

C Extra + Quercetin

by Natural Factors · capsule · 60 easy swallow capsules

  • On the market (NIH)
  • UPC 0 68958 01398 5
  • DSLD label 247524
  • Serving 1 capsule

C Extra + Quercetin by Natural Factors lists 2 ingredients, 2 with an amount per serving of 1 capsule, such as 500 mg of vitamin C and 250 mg of quercetin. Its current label entered the NIH Dietary Supplement Label Database on April 22, 2021.

What is in C Extra + Quercetin?

Each row as the label prints it, per serving of 1 capsule. The capsule beside an amount places it among every product in the NIH database that lists the same ingredient: the bar is the middle half of their amounts, the line in it the median, the whiskers the 10th and 90th percentiles; the green tick is the FDA Daily Value and the red dashed tick the adult upper limit (IOM).

C Extra + Quercetin: Supplement Facts rows against the market (DSLD label 247524, January 2026 release)
IngredientAmount% DVAmong products listing it
Vitamin Cas Ascorbic Acid500 mg556%Vitamin C in C Extra + Quercetin against 18,583 products500 mg per serving; the middle half of products list 60 mg to 270 mg, the median 100 mg.DV 90 mgUL 2,000 mg500 mg

Higher than 81% of 18,583 products listing vitamin C (median 100 mg).

Quercetinas Bioflavonoids250 mgQuercetin in C Extra + Quercetin against 1,548 products250 mg per serving; the middle half of products list 26.5 mg to 250 mg, the median 100 mg.250 mg

Higher than 71% of 1,548 products listing quercetin (median 100 mg).

Source: NIH ODS Dietary Supplement Label Database, label 247524 (entered April 22, 2021), version 9.4.0. See the label on DSLD. Amounts are what the maker printed; DSLD does not test products. Daily Values: the FDA's Daily Value page.

Is that a lot?

Every amount on this label with a position sits within the middle 80% of the products that list the same ingredient.

The NIH database records one serving a day from the label's directions; its % Daily Values are for adults and children 4 or more years of age. The directions as printed are further down this page.

The Tolerable Upper Intake Level is the most of a nutrient per day, from food, water and supplements together, that is likely to pose no risk for almost all adults (Institute of Medicine, 2011). It does not apply under medical supervision. This page compares labels; it is not medical advice.

Sources: amounts from the DSLD label; Daily Values from 21 CFR 101.9(c)(8)(iv); adult upper limits from the Institute of Medicine's DRI summary tables (2011). How positions are computed.

Which products have the closest formulas?

6 products list the very same ingredients; the nearest amounts come first.

Source: ingredient lists of every product's current label in DSLD (version 9.4.0); similarity weights each shared ingredient by how rare it is.

What does the label say about taking it?

Quoted from the label as DSLD transcribed it: the maker's words, including any claim about what the product does, which the FDA has not evaluated and PlainVitamins does not endorse.

Directions
Suggested Usage: 1 capsule per day or as directed by a health professional.
Warnings
Cautions: As with any supplement, consult your health professional before use if you are pregnant, breastfeeding, or trying to conceive, or if you are taking medication, have a medical condition, or anticipate a surgery.
Keep out of reach of children.
Sealed for your protection. Do not use if seal is broken.
Allergens and what it does not contain
Contains no artificial colors, preservatives, or sweeteners; no dairy, starch, sugar, wheat, gluten, yeast, soy, corn, egg, fish, shellfish, animal products, salt, tree nuts, or GMOs.
Storage
For freshness, store in a cool, dry place.

Source: label statements in DSLD label 247524.

What else is on the label?

Other ingredients: Vegetarian Capsule, Magnesium Stearate, Stearic Acid, Microcrystalline Cellulose, Silicon Dioxide.

Seals and symbols as the label prints them (the maker's; a certifier's own list confirms a seal): Isura Non-GMO - Mass Spec Documentation - Lab Tested.

How many labels does C Extra + Quercetin have?

One label is on file, entered on April 22, 2021.

  1. Label 247524 (current) Entered April 22, 2021 · on the market · 60 easy swallow capsules · UPC 0 68958 01398 5

Source: DSLD label entry and market events, version 9.4.0 (labels entered through September 25, 2025).

Who makes it?

The label names Natural Factors Canada (manufacturer). All Natural Factors products.

Where next?