Grade: C

MEDIUM RISK

KOS

Item: KOS
Rating: 50
Author: SupplementChecker

KOS has a SupplementChecker.co trust score of 50/100, which is a Grade C and indicates a MEDIUM risk level. KOS does not appear to conduct third-party testing on its supplements. Consumers should be aware of the lack of independent verification when considering KOS products.

KOS Trust Summary

Trust Score: 50/100 (Fair)
Grade: C
Risk Level: MEDIUM
Third-Party Tested: No
FDA Recalls: 0
Adverse Events: 2

KOS has a trust score of 50/100 (Fair). The brand is not third-party tested by NSF, USP, or Informed Sport, has no FDA recalls on record and 2 adverse event reports.

Where to Buy KOS

Purchase from trusted retailers. We may earn a commission at no extra cost to you.

Buy on iHerb Buy on Amazon

Check another brand:

e.g. Nature Made, Thorne, NOW Foods...

Check

Red Flags

⚠No third-party testing certifications found
⚠No GMP certification visible

Verified Strengths

✓Clean FDA record — no warnings, recalls, or significant adverse events

Certifications

No certifications on record. This brand has not demonstrated GMP compliance or third-party testing verification.

FDA Record

FDA Warning Letters

Recalls

Adverse Reports

Is KOS Third-Party Tested?

No — KOS is not currently third-party tested by independent certifiers like NSF, USP, or Informed Sport. No GMP certification was found on record either. 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 KOS a Good Brand?

KOS scores 50/100 (C) — this is a below-average score. We recommend considering brands with third-party certifications like NSF or USP. KOS has a clean FDA record with no warnings or recalls. The brand does not currently hold third-party testing certifications.

About KOS

KOS is a supplement brand operating as an independent company with headquarters in the US. The founding date of KOS is unknown. They offer a range of supplements in the specialty category.

Product Specialization

KOS specializes in the specialty supplement category. While specific product lines are not detailed here, specialty supplements often include items targeting niche health needs or dietary preferences.

Testing & Certifications Explained

KOS does not have any third-party certifications on record. This means that their products are not independently tested or verified by organizations like NSF, USP, or Informed-Sport. The absence of these certifications means consumers must rely solely on the brand's own claims regarding product quality and safety. Consumers concerned about ingredient accuracy or contamination should consider brands that invest in third-party testing.

How KOS Compares

Compared to other brands in the specialty supplement category, KOS's trust score of 50/100 is in the lower range. For example, a brand like Garden of Life (trust score 75/100) undergoes more rigorous third-party testing. Another competitor, NOW Foods (trust score 80/100), also has a stronger commitment to certifications. Consumers should compare KOS reviews and testing policies against those of competitors to make an informed decision.

Buying Guidance

Given KOS's trust score and lack of third-party testing, consumers should exercise caution. Purchase KOS products directly from the manufacturer or reputable retailers to minimize the risk of counterfeit products. Carefully examine product labels and consider consulting with a healthcare professional before use.

Frequently Asked Questions

Has KOS had any recalls?

No — as of 2026, KOS has zero FDA product recalls on record. They maintain a clean FDA record with no warning letters or significant adverse event reports. KOS received a trust score of 50/100 from SupplementChecker.

Are KOS supplements third-party tested?

No — KOS supplements are not currently third-party tested by independent certifiers like NSF, USP, or Informed Sport. No independent testing or GMP certification was found on record.

Is KOS safe?

KOS received a trust score of 50/100 (grade: C, risk level: MEDIUM). 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 KOS a good brand?

KOS scores 50/100 (grade: C) — 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.

Get FDA Recall Alerts

We'll notify you when FDA recalls affect supplement brands you care about.

Compare Similar Brands

Brands in similar categories with comparable trust profiles. Compare certifications, scores, and safety records.

65/100

Lower rated

Brightside

Grade B • Higher score

65/100

Lower rated

Outwork Nutrition

Grade B • Higher score

65/100

Lower rated

Vital Vitamins

Grade B • Higher score

65/100

Lower rated

Thesis

Grade B • Higher score

65/100

Lower rated

Traditional Medicinals

Grade B • Higher score

Want more comparisons? Browse our supplement categories or check our buying guides.

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.

Promote Your Trust Score

Embed this badge on your site — it displays KOS's verified trust score and links back to this profile page. Helps show buyers you're transparent about third-party testing.

Small · 220×110

<iframe src="https://supplementchecker.co/embed/kos/" width="220" height="110" frameborder="0" loading="lazy" title="KOS trust score by SupplementChecker"></iframe>

Medium · 320×160

<iframe src="https://supplementchecker.co/embed/kos/" width="320" height="160" frameborder="0" loading="lazy" title="KOS trust score by SupplementChecker"></iframe>

Large · 420×210

<iframe src="https://supplementchecker.co/embed/kos/" width="420" height="210" frameborder="0" loading="lazy" title="KOS trust score by SupplementChecker"></iframe>

Paste the snippet anywhere on your site. The badge updates automatically when KOS's trust score changes.

Own this brand? Contact us to update your information.

Want to find supplements you can trust?

Third-party testing is the single best indicator of supplement quality. We analyzed KOS and 500+ other brands to find the ones that actually prove what's on the label.

See the best third-party tested supplements →