Which vitamin C brands are third-party tested?
Our picks, each format ranked separately: Capsules and tablets: Nature Made Vitamin C Extra Strength 1000 mg (300 tablets); gummies and chewables: Nature Made Chewable Vitamin C 500 mg (150 tablets). Where to buy
9 of the 81 vitamin C products we track are confirmed at the package by USP. 2 match a row in USP's directory that is not yet confirmed for the package we price. 68 appear in no database we searched. 2 match a listing that may cover them, and whether it does is not settled either way, so they are listed separately below rather than counted as absent.
A certifier lists a specific package against each certificate. A brand can sell the same formula in several sizes, or several flavors, and have one of them listed, so “this brand is NSF certified” can be true while the tub in your hand is not the tub NSF tested. The middle group below is that gap.
NSF names packages by size and count, so one bottle can be named while a larger one of the same line is not. USP's directory names a product and a strength but no package size. Each row's format, strength and count come from the brand's own label and store page.
Confirmed at this exact package, 9
The strongest evidence available here. For NSF, the listing names the package size sold; it was opened, its package text recorded, and its ID is on the product page. For USP, which names products rather than packages, the product is in USP's directory and the USP Verified Mark is on this package's own label, and both are on the product page.
| Product | Type | Per 1,000 mg | Certificate |
|---|---|---|---|
| Nature Made Vitamin C Extra Strength 1000 mg (300 tablets) | Capsules, softgels and tablets | $0.138 | USP Verified, product in directory, mark on label |
| Nature Made Vitamin C 500 mg (100 tablets) | Capsules, softgels and tablets | $0.16 | USP Verified, product in directory, mark on label |
| Nature Made Vitamin C Extra Strength 1000 mg (100 tablets) | Capsules, softgels and tablets | $0.162 | USP Verified, product in directory, mark on label |
| Nature Made Vitamin C 500 mg with Rose Hips (130 caplets) | Capsules, softgels and tablets | $0.188 | USP Verified, product in directory, mark on label |
| Nature Made Chewable Vitamin C 500 mg (150 tablets) | Gummies and chewables | $0.296 | USP Verified, product in directory, mark on label |
| Nature Made Chewable Vitamin C 500 mg (60 tablets) | Gummies and chewables | $0.36 | USP Verified, product in directory, mark on label |
| Nature Made Vitamin C 500 mg (60 softgels) | Capsules, softgels and tablets | $0.466 | USP Verified, product in directory, mark on label |
| Nature Made Vitamin C Extra Strength 500 mg Gummies (60 gummies) | Gummies and chewables | $0.986 | USP Verified, product in directory, mark on label |
| Nature Made Zero Sugar Vitamin C Gummies 250 mg per serving (100 gummies) | Gummies and chewables | $1.52 | USP Verified, product in directory, mark on label |
Listed, not confirmed for this package, 2
USP's directory holds a row matching the product. USP names no package, so confirming one takes two things, the row filed under this brand and the USP Verified Mark on this label, and here they are not both settled yet. Each product page says which. Neither confirmed nor absent.
| Product | Type | Per 1,000 mg | Certificate |
|---|---|---|---|
| Nature Made Vitamin C 500 mg (500 tablets) | Capsules, softgels and tablets | $0.13 | USP Verified, directory row not yet confirmed for this package |
| Nature Made Vitamin C 500 mg (250 tablets) | Capsules, softgels and tablets | $0.144 | USP Verified, directory row not yet confirmed for this package |
Searched, and not found, 68
Not listed by NSF Certified for Sport when we read its full directory. These programs certify what a company submits to them, so a product can be absent from the database simply because it was never entered, which is not a finding against it.
Not settled either way, 2
A certifier's list holds an entry that may cover these, and the entry does not say whether it does. Neither confirmed nor absent; each product page has the detail.
| Product | Type | Per 1,000 mg | Certificate |
|---|---|---|---|
| Nature Made Vitamin C Extra Strength Dosage 1000 mg Chewables (90 tablets) | Gummies and chewables | $0.353 | Unknown |
| Nature Made Vitamin C Gummies Maximum Strength Dosage 1000 mg per serving (80 gummies) | Gummies and chewables | $0.975 | Unknown |
NSF Certified for Sport, the Informed programs' published product lists, the IFOS directory and USP's directory are each read in full, and each product page names the day. A product missing from this page has not failed a check. It has not had one.
Where to buy: the vitamin C shortlist
The pick is the cheapest certified product, at the exact package sold where the certifier names packages, with no adverse finding on record, a price its retailer let us read recently, and no more than a year’s supply at the label’s serving; per delivered dose where the retailer publishes a delivery rate. Where none does, it is the cheapest such product before delivery, and it says how far the order is from free delivery. It is the same pick the category page shows. Any answer shown beside it is the cheapest under a different rule and says so on its own line; answers that cost more than the pick fold under one line until you ask for them.
How these lines are chosen
Among 29 products and 29 retailer listings we track; Amazon and Walmart are not included. A month is thirty doses of the size in the heading, priced the same way as the per-dose figure beside it. “Delivery known” ranks only products whose retailer publishes a delivery rate; a cheaper product with an unpublished rate is on its own line, or in the full list below.
How these lines are chosen
Among 24 products and 24 retailer listings we track; Amazon and Walmart are not included. A month is thirty doses of the size in the heading, priced the same way as the per-dose figure beside it. “Delivery known” ranks only products whose retailer publishes a delivery rate; a cheaper product with an unpublished rate is on its own line, or in the full list below.
A pick has to be independently certified, at the exact package sold where the certifier names packages, and carry no recall or failed test. Nothing we track here is yet. Each of these misses at least one bar, and says which:
How these lines are chosen
Among 16 products and 16 retailer listings we track; Amazon and Walmart are not included. A month is thirty doses of the size in the heading, priced the same way as the per-dose figure beside it. “Delivery known” ranks only products whose retailer publishes a delivery rate; a cheaper product with an unpublished rate is on its own line, or in the full list below.
How these lines are chosen
Among 12 products and 12 retailer listings we track; Amazon and Walmart are not included. A month is thirty doses of the size in the heading, priced the same way as the per-dose figure beside it. “Delivery known” ranks only products whose retailer publishes a delivery rate; a cheaper product with an unpublished rate is on its own line, or in the full list below.
A pick has to be independently certified, at the exact package sold where the certifier names packages, and carry no recall or failed test. Nothing we track here is yet. Each of these misses at least one bar, and says which:
Full comparison of every product in this category: Vitamin C. Every question we answer: the question index.
What this rests on: prices we last recorded at the retailer named on each product page, which go stale, and each page says when it was checked; the products we track, not every product sold, and Amazon and Walmart are not among the stores; listings and labels read at the source, each linked from the page. Found an error? Tell us. The full method: How we compare.