PlainVitamins

Flex

by Core Nutritionals · tablet or pill · 240 tablets

  • On the market (NIH)
  • UPC 6 72975 00969 4
  • DSLD label 297981
  • Serving 8 tablets
  • 30 servings

Flex by Core Nutritionals lists 12 ingredients, 12 with an amount per serving of 8 tablets, such as 500 mg of vitamin C, 25 mcg (1,000 IU) of vitamin D3, 40 mg of calcium and 1,400 mg of glucosamine sulfate potassium chloride. Its current label entered the NIH Dietary Supplement Label Database on October 24, 2023.

What is in 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).

Flex: Supplement Facts rows against the market (DSLD label 297981, January 2026 release)
IngredientAmount% DVAmong products listing it
Vitamin Cas Ascorbic Acid500 mg556%Vitamin C in 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).

Vitamin D3as Cholecalciferol25 mcg (1,000 IU)125%Vitamin D in 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).

Calciumas Dicalcium Phosphate40 mg3%Calcium in FLEX against 17,831 products40 mg per serving; the middle half of products list 50 mg to 252 mg, the median 115 mg.DV 1,300 mgUL 2,500 mg40 mg

79% of 17,831 products listing calcium give more (median 115 mg).

Glucosamine Sulfate Potassium Chloride1,400 mgGlucosamine Sulfate in 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).

Methylsulfonylmethane1,000 mgMethylsulfonylmethane in 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).

Boswelliaas Boswellia serrata37% boswellic acids800 mgBoswellia in 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).

Chondroitin Sulfate Sodium800 mgChondroitin Sulfate in 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).

Cissus quadrangularis Stem Extractas Ketosterol10% ketosterol800 mgCissus quadrangularis in 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).

Turmeric Root Extractas Curcumin95% curcumin500 mgTurmeric in 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).

Bromelain2400 GDU/g400 mgBromelain in 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).

Black Cherry Fruit Extract4:1100 mgWild Cherry in 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).

Black Pepper Fruit Extractas Piperine95% piperine5 mgBlack Pepper in 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).

Source: NIH ODS Dietary Supplement Label Database, label 297981 (entered October 24, 2023), version 9.4.0. See the label on DSLD or its label image (PDF). 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 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?

The products whose ingredient lists overlap most with 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 8 tablets daily with or without food.
Warnings
Warning: This product is only intended for use in healthy adults 18 years of age or older.
Pregnant or nursing women should not use this product. Consult your healthcare provider before using this product, especially if you are taking any prescription, over the counter medication, dietary supplement product, 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 MAOI (Monoamine Oxidase Inhibitor) or any other medication.
Discontinue use and consult your health care professional if you experience adverse reaction to this product. Discontinue use 2 weeks prior to surgery. Do not exceed recommended serving. Do not use if safety seal is broken or missing.
Keep out of reach of children.
Allergen statement: Contains shellfish.
Warning: Consuming this product can expose you to chemicals including lead, which is known to the State of California to cause cancer. For more information, go to www.P65Warnings.ca.gov.

Source: label statements in DSLD label 297981.

What else is on the label?

Other ingredients: Stearic Acid, Croscarmellose Sodium, Maltodextrin, Silicon Dioxide, Magnesium Stearate, Food Glaze, micro fine Wax.

How many labels does Flex have?

5 labels are on file under this name since November 24, 2015: other sizes, label designs and reformulations. The current one leads this page.

  1. Label 297981 (current) Entered October 24, 2023 · on the market · 240 tablets · UPC 6 72975 00969 4
  2. Label 269177 Entered June 16, 2022 · off the market November 16, 2022 · 240 tablets · UPC 6 72975 00969 4
  3. Label 183122 Entered November 21, 2018 · on the market · 240 tablets · UPC 8 50757 00108 5
  4. Label 74219 Entered May 24, 2017 · off the market June 20, 2018 · 240 tablets · UPC 8 50757 00108 5
  5. Label 53607 Entered November 24, 2015 · off the market April 19, 2017 · 240 tablets · UPC 8 50757 00108 5

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), Statesville, NC. All Core Nutritionals products.

Where next?