PlainVitamins

Core Flex

by Core Nutritionals · tablet or pill · 240 tablets

  • Off the market since May 2015 (NIH)
  • UPC 8 50757 00108 5
  • DSLD label 30789
  • Serving 4 to 8 tablets; amounts per 8 tablets
  • 30 servings

Core Flex by Core Nutritionals lists 11 ingredients, 11 with an amount per serving of 8 tablets, such as 800 mg of chondroitin sulfate, 1,400 mg of glucosamine sulfate, 1,000 mg of MSM and 800 mg of cissus quadrangularis. Its current label entered the NIH Dietary Supplement Label Database on February 26, 2014.

What is in Core Flex?

Each row as the label prints it, per serving of 8 tablets. 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).

Core Flex: Supplement Facts rows against the market (DSLD label 30789, January 2026 release)
IngredientAmount% DVAmong products listing it
Chondroitin Sulfate800 mgChondroitin Sulfate in Core Flex against 950 products800 mg per serving; the middle half of products list 200 mg to 1,200 mg, the median 400 mg.800 mg

Higher than 66% of 950 products listing chondroitin sulfate (median 400 mg). Per day at the most servings: 1,600 mg.

Glucosamine Sulfate1,400 mgGlucosamine Sulfate in Core Flex against 875 products1.4 g per serving; the middle half of products list 0.5 g to 1.5 g, the median 1 g.1.4 g

Higher than 64% of 875 products listing glucosamine sulfate (median 1 g). Per day at the most servings: 2.8 g.

MSM1,000 mgMethylsulfonylmethane in Core Flex against 1,454 products1,000 mg per serving; the middle half of products list 150 mg to 1,000 mg, the median 500 mg.1,000 mg

Higher than 74% of 1,454 products listing methylsulfonylmethane (median 500 mg). Per day at the most servings: 2,000 mg.

Cissus quadrangularisas ketosteronesCissus quadrangularis (Form: 10% ketosterones) Genus: Cissus Species: quadrangularis800 mgCissus quadrangularis in Core Flex against 140 products800 mg per serving; the middle half of products list 100 mg to 800 mg, the median 400 mg.800 mg

Higher than 72% of 140 products listing cissus quadrangularis (median 400 mg). Per day at the most servings: 1,600 mg.

Black Cherry extractBlack Cherry extract Genus: Prunus Species: cerasus Note: 5:1100 mgWild Cherry in Core Flex against 68 products100 mg per serving; the middle half of products list 100 mg to 1,000 mg, the median 450 mg.100 mg

71% of 68 products listing wild cherry give more (median 450 mg). Per day at the most servings: 200 mg.

Turmericas CurcuminTurmeric (Form: 95% Curcumin)500 mgTurmeric in Core Flex against 2,369 products500 mg per serving; the middle half of products list 50 mg to 500 mg, the median 150 mg.500 mg

Higher than 72% of 2,369 products listing turmeric (median 150 mg). Per day at the most servings: 1,000 mg.

Boswelliaas boswellic acidsBoswellia (Form: 37% boswellic acids)800 mgBoswellia in Core Flex against 665 products800 mg per serving; the middle half of products list 100 mg to 290 mg, the median 135 mg.800 mg

Higher than 95% of 665 products listing boswellia (median 135 mg). Per day at the most servings: 1,600 mg.

BromelainBromelain Note: 2400 GDU/g400 mgBromelain in Core Flex against 1,337 products400 mg per serving; the middle half of products list 25 mg to 200 mg, the median 50 mg.400 mg

Higher than 87% of 1,337 products listing bromelain (median 50 mg). Per day at the most servings: 800 mg.

Vitamin Cas Ascorbic Acid500 mg833%Vitamin C in Core Flex 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). Per day at the most servings: 1,000 mg.

Vitamin D3as Cholecalciferol1,000 IU (25 mcg)250%Vitamin D in Core Flex against 14,175 products25 mcg per serving; the middle half of products list 10 mcg to 25 mcg, the median 15 mcg.DV 20 mcgUL 100 mcg25 mcg

Higher than 59% of 14,175 products listing vitamin D (median 15 mcg). Per day at the most servings: 50 mcg.

Black Pepper extractas PiperineBlack Pepper extract (Form: 95% Piperine)5 mgBlack Pepper in Core Flex against 2,363 products5 mg per serving; the middle half of products list 5 mg to 10 mg, the median 5 mg.5 mg

33% of 2,363 products listing black pepper give more (median 5 mg). Per day at the most servings: 10 mg.

Source: NIH ODS Dietary Supplement Label Database, label 30789 (entered February 26, 2014), 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?

The rows in the top or bottom tenth of the products that list the same ingredient, and any above the adult upper limit at the most servings a day the directions give:

  • Its 800 mg of boswellia is higher than 95% of the 665 boswellia products that print an amount; 21 list more.

The NIH database records 2 servings 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?

The products whose ingredient lists overlap most with Core Flex's, rare ingredients counting for more.

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
Directions: Take 4 tablets twice daily. As additional 2-4 tablets per day can be taken if desired.
Warnings
Before using this product consult with your physician if you are using any prescription or over the counter medication or if you have any pre-existing medical condition including but not limited to: high or low blood pressure, cardiac arrhythmia, stroke, heart, liver, kidney or thyroid disease, seizure disorder, psychiatric disease, diabetes, difficulty urinating due to prostate enlargement or if you are taking a MAO-B inhibitor or any other medication.
Discontinue use and consult your health care professional if you experience any adverse reaction to this product. Do not exceed recommended serving. Do not use if safety seal is broken or missing.
Not for use by pregnant or nursing women.
Warning: Keep out of the reach of children.
Storage
Store in a cool, dry place.

Source: label statements in DSLD label 30789.

What else is on the label?

Other ingredients: Hydroxypropylcellulose, Calcium Carbonate, Maltodextrin, Stearic Acid, Sodium Croscarmellose, Magnesium Stearate.

Seals and symbols as the label prints them (the maker's; a certifier's own list confirms a seal): CORE NUTRITIONALS.

How many labels does Core Flex have?

One label is on file, entered on February 26, 2014.

  1. Label 30789 (current) Entered February 26, 2014 · off the market May 19, 2015 · 240 tablets · UPC 8 50757 00108 5

DSLD also links this label to: Flex (image difference, same product), Flex (image difference, same product), Flex (image difference, same product).

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

Who makes it?

The label names Core Nutritionals, LLC (distributor), Arlington, Virginia. All Core Nutritionals products.

Where next?