Grade: D

HIGH RISK

One A Day

Item: One A Day
Rating: 45
Author: SupplementChecker

Part of Bayer

https://www.oneaday.com Est. 1940 (86 years)

One A Day has a SupplementChecker.co trust score of 45/100, which is a Grade D and indicates a HIGH risk level. One A Day does not appear to be third-party tested. Consumers should be aware of a high number of FDA adverse event reports associated with One A Day products.

One A Day Trust Summary

Trust Score: 45/100 (Below Average)
Grade: D
Risk Level: HIGH
Third-Party Tested: No
FDA Recalls: 0
Adverse Events: 118
Years in Business: 86 years
GMP Certified: Yes

One A Day has a trust score of 45/100 (Below Average). The brand is not third-party tested by NSF, USP, or Informed Sport, has no FDA recalls on record and 118 adverse event reports and has been in business for 86 years.

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Red Flags

⚠High number of FDA adverse event reports (118)
⚠No third-party testing certifications found

Verified Strengths

✓Established brand — operating since 1940 (86 years)

Certifications

GMP Certified

GMP certification ensures manufacturing quality standards are met, but does not verify that product contents match the label through independent testing. Look for NSF, USP, or Informed Sport certifications for third-party verified products.

FDA Record

FDA Warning Letters

Recalls

118

Adverse Reports

Is One A Day Third-Party Tested?

No — One A Day is not currently third-party tested by independent certifiers like NSF, USP, or Informed Sport. They do hold GMP certification, which ensures manufacturing quality but does not independently verify product contents. We recommend looking for brands with verified third-party testing for the highest confidence in product quality. See our guide to third-party tested supplements.

Is One A Day a Good Brand?

One A Day scores 45/100 (D) — this is a below-average score. We recommend considering brands with third-party certifications like NSF or USP. One A Day has a clean FDA record with no warnings or recalls. The brand does not currently hold third-party testing certifications.

About One A Day

One A Day is a multivitamin brand that has been in business since 1940, giving it 86 years of operating history. It is owned by parent company Bayer and headquartered in the US. One A Day is a well-known brand in the vitamin and supplement space.

Product Specialization

One A Day specializes in multivitamins for various demographics, including men, women, children, and seniors. They offer a range of multivitamin formulations designed to address specific health needs.

Testing & Certifications Explained

One A Day is GMP certified, which means the company adheres to Good Manufacturing Practices set by regulatory bodies. However, One A Day is not third-party tested. This means that an independent organization does not verify the contents and purity of One A Day products. Consumers seeking third-party tested supplements should look for brands with certifications like USP, NSF, or Informed-Sport.

How One A Day Compares

Compared to competitors like Garden of Life (trust score 78/100) and Thorne Research (trust score 92/100), One A Day's trust score is significantly lower. Garden of Life and Thorne Research both utilize third-party testing and have higher transparency standards. Nature Made, another competitor, has a similar trust score (50/100) and also lacks comprehensive third-party testing.

Buying Guidance

Given One A Day's low trust score and lack of third-party testing, consumers should carefully consider alternative brands. If you choose to use One A Day products, purchase from reputable retailers and carefully monitor for any adverse reactions. Check for any potential One A Day recall announcements from the FDA.

Frequently Asked Questions

Has One A Day had any recalls?

No — as of 2026, One A Day has zero FDA product recalls on record. One A Day received a trust score of 45/100 from SupplementChecker.

Are One A Day supplements third-party tested?

No — One A Day supplements are not currently third-party tested by independent certifiers like NSF, USP, or Informed Sport. They do have GMP (Good Manufacturing Practice) certification, which ensures manufacturing quality but does not independently verify product contents.

Is One A Day safe?

One A Day received a trust score of 45/100 (grade: D, risk level: HIGH). This score is calculated from FDA records, third-party certifications, adverse event reports, and transparency practices. No FDA warnings or recalls are on record.

Is One A Day a good brand?

One A Day scores 45/100 (grade: D) — this is below average. We recommend looking for brands with third-party certifications like NSF or USP. They do not currently hold third-party testing certifications like NSF, USP, or Informed Sport. No FDA warnings or recalls found.

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How We Calculated This Score

Every brand starts with a baseline score of 70/100.

Points added for: Third-party certifications (NSF +15, USP +15, Informed Sport +10), publishing lab results (+10), clean regulatory record (+10), 10+ years in business (+10), organic certification (+5).

Points deducted for: FDA warning letters (-25), product recalls (-20), high adverse events (-15), no third-party testing (-15), proprietary blends (-10), no GMP (-10).

Score is capped at 0-100. Grade and risk level are derived from the final score.

All data sourced from FDA.gov, Health Canada (LNHPD / recalls-rappels), NSF.org, USP.org, and publicly available brand information. Last updated: 4/9/2026.

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