PlainVitamins

Buffered C Powder

by Thorne · powder · 8.47 ounces

  • On the market (NIH)
  • UPC 6 93749 15502 7
  • DSLD label 337854
  • Serving 5.7 g (One Scoop)
  • 42 servings

Buffered C Powder by Thorne lists 4 ingredients, 4 with an amount per serving of 5.7 g, such as 2.35 g of vitamin C, 350 mg of calcium, 350 mg of magnesium and 99 mg of potassium. Its current label entered the NIH Dietary Supplement Label Database on September 25, 2025.

What is in Buffered C Powder?

Each row as the label prints it, per serving of 5.7 g. 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).

Buffered C Powder: Supplement Facts rows against the market (DSLD label 337854, January 2026 release)
IngredientAmount% DVAmong products listing it
Vitamin Cas Ascorbic Acid2.35 g2,611%Vitamin C in Buffered C Powder against 18,583 products2,350 mg per serving; the middle half of products list 60 mg to 270 mg, the median 100 mg.DV 90 mgUL 2,000 mg2,350 mg

Higher than over 99% of 18,583 products listing vitamin C (median 100 mg). 1.2 times the adult UL a day.

Calciumas Ascorbic Acid, Calcium Ascorbate350 mg27%Calcium in Buffered C Powder against 17,831 products350 mg per serving; the middle half of products list 50 mg to 252 mg, the median 115 mg.DV 1,300 mgUL 2,500 mg350 mg

Higher than 81% of 17,831 products listing calcium (median 115 mg).

Magnesiumas Magnesium Ascorbate350 mg83%Magnesium in Buffered C Powder against 14,003 products350 mg per serving; the middle half of products list 30 mg to 200 mg, the median 86 mg.UL 350 mgDV 420 mg350 mg

Higher than 91% of 14,003 products listing magnesium (median 86 mg).

Potassiumas Potassium Ascorbate99 mg2%Potassium in Buffered C Powder against 11,614 products99 mg per serving; the middle half of products list 50 mg to 190 mg, the median 99 mg.DV 4,700 mg99 mg

49% of 11,614 products listing potassium give more (median 99 mg).

Source: NIH ODS Dietary Supplement Label Database, label 337854 (entered September 25, 2025), 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:

  • At 1 serving a day, the most its directions give, the label lists 2,350 mg of vitamin C, 1.2 times the adult Tolerable Upper Intake Level.
  • Its 350 mg of magnesium is higher than 91% of the 14,003 magnesium products that print an amount; 1,247 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?

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 use: Mix 1 scoop with at least 8 ounces of water daily or as recommended by your health-care practitioner.
Warnings
Tamper evident: Use only if bottle is sealed.
If pregnant, consult your health-care practitioner before using this product.
Allergens and what it does not contain
Gluten free
Storage
Store tightly sealed in a cool, dry place.

Source: label statements in DSLD label 337854.

What else is on the label?

Seals and symbols as the label prints them (the maker's; a certifier's own list confirms a seal): Manufactured in the USA using US & imported ingredients NSF Contents Certified. Listed with: NSF certified (contents or GMP) (a seal is the label's claim; the certifier's own list confirms it).

How many labels does Buffered C Powder have?

7 labels are on file under this name since October 25, 2018: other sizes, label designs and reformulations. The current one leads this page.

  1. Label 337854 (current) Entered September 25, 2025 · on the market · 8.47 ounces · UPC 6 93749 15502 7
  2. Label 328821 Entered February 23, 2025 · off the market June 17, 2025 · 8.32 ounces · UPC 6 93749 15502 7
  3. Label 306264 Entered February 22, 2024 · off the market October 22, 2024 · 8.32 ounces · UPC 6 93749 15502 7
  4. Label 284199 Entered February 21, 2023 · off the market February 20, 2024 · 8.32 ounces · UPC 6 93749 15502 7
  5. Label 260359 Entered October 22, 2021 · off the market November 30, 2022 · 8.32 ounces · UPC 6 93749 15502 7
  6. Label 242351 Entered January 22, 2021 · off the market October 4, 2021 · 8.32 oz. · UPC 6 93749 15502 7
  7. Label 181779 Entered October 25, 2018 · off the market December 16, 2020 · 8.15 oz. · UPC 6 93749 15502 7

DSLD also links this label to: Buffered C Powder (image difference, same product), Buffered C Powder (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 Thorne Research, Inc. (manufacturer). All Thorne products.

Where next?