Choosing a Third-Party Test
Third-party testing is the only way to verify what is actually in a product. Whether you are testing your own tap water, validating a supplement, or auditing a brand's claims, here is how to choose the right lab, the right tests, and what to expect in terms of cost and timeline.
When to commission testing
Tap water: when moving into a new home, after plumbing work, if you have a private well (test annually), before buying a filtration system, or if your utility has a history of EPA violations. Check your local water quality first via our zip code lookup tool.
Bottled water: if the brand does not publish a COA, or the published COA is outdated (more than 12 months old), or you want to verify claims independently.
Supplements: if the product is not USP Verified or NSF Certified, if you are taking high doses of anything, or if the brand uses proprietary blends that hide actual doses.
Recommended labs
SimpleLab (Tap Score)
Consumer-friendly water testing. You order a kit, collect a sample at home, mail it back, and receive a detailed report online. ISO 17025 accredited partner labs. Three tiers: Essential ($150, basic metals and bacteria), Advanced ($250, adds PFAS and pesticides), Extended ($400, comprehensive with radiologicals).
Turnaround: 7-10 business days. Best for homeowners testing tap water.
Eurofins
Global laboratory network with ISO 17025 accreditation. Handles water, food, supplements, environmental samples. Used by brands, regulators, and researchers. More complex ordering process -- typically requires contacting a sales representative. Pricing varies by panel but expect $200-$600 for water, $300-$800 for supplements.
Turnaround: 10-15 business days. Best for brands and serious consumers.
NSF International
Primarily a certification body rather than a testing-for-hire lab. NSF certifies water filters (NSF 42, 53, 401), supplements (NSF Certified for Sport), and water contact materials (NSF 61). If you want a product certified, NSF runs ongoing testing and audits.
Certification process: weeks to months. Best for manufacturers seeking third-party certification.
What to test by product type
Drinking water ($150-$400): heavy metals (lead, arsenic, cadmium, chromium-6), PFAS (EPA 533/537.1), bacteria (total coliforms, E. coli), nitrate/nitrite, VOCs, and minerals. If you are on well water, add radiologicals.
Supplements ($200-$600): identity (is the labeled ingredient present), potency (dose accuracy), heavy metals (USP 232/233), microbial limits, and dissolution. For herbal supplements, add pesticide screening.
Personal care ($250-$500): heavy metals, PFAS, phthalates, 1,4-dioxane, formaldehyde. Testing personal care products is less standardized than water or supplements.
Cost and turnaround summary
Water (consumer): $150-$400. Results in 7-15 business days. SimpleLab is the easiest entry point.
Supplements: $200-$600 per product. Results in 10-20 business days. Eurofins or contract labs with USP method capabilities.
Rush testing: most labs offer expedited service for 50-100% surcharge. SimpleLab does not offer rush options.
Interpreting results: read our COA reading guide before diving into your report. Focus on MCL comparisons and ND results for contaminants.