Über 65.000 Labore weltweit – Tendenz steigend
Getting Started

Supplement Testing for New Brands: What to Do First (Before You Waste Money)

14 min read Updated June 9, 2026

By someone who learned the hard way so you don't have to.


So You've Got Your First Batch of Supplements. Now What?

You wired a few thousand dollars to a contract manufacturer. The bottles are sitting in your garage. The label looks fire. The logo you spent $500 on Fiverr is on point. You're ready to launch.

Hold up.

Before you sell a single bottle, before you send a single influencer sample, before you even post that unboxing video — you need test results. Not because I'm some compliance nerd who gets excited about ISO standards. Because if something goes wrong, you don't have a "small setback." You have a lawsuit, an FDA warning letter, a destroyed reputation, and a very awkward phone call with your mom explaining why her friend got sick from your product.

I've been building supplement brands for years. I've seen both disasters up close: founders who tested literally nothing and got obliterated by a single contamination event, and founders who torched $15K on unnecessary tests before they'd made their first dollar in revenue. Both paths are dumb. This guide is the smart middle path — what to test, when to test it, what to skip, and how to not go broke doing it.


The Minimum Testing You NEED Before Selling Your First Bottle

No fluff. Here's what's actually required:

1. Heavy Metals Panel (Non-Negotiable)

Arsenic, lead, cadmium, mercury. Every brand needs this — including your organic, plant-based superfood. Soil absorbs metals. Equipment sheds particles. Raw materials get contaminated in transit. "Natural" doesn't mean clean. Arsenic is natural too.

Cost: $150–$350 per batch.

2. Microbial Testing (Non-Negotiable)

Total plate count, yeast and mold, E. coli, Salmonella, Staph. aureus. If it goes into someone's body, it cannot be a petri dish. Critical for powders, liquids, gummies — anything above 0.6 water activity. I once watched a startup lose $40K in pre-sold inventory because the entire production run was moldy.

Cost: $150–$400 per batch.

3. Potency / Label Claim Verification

Bottle says "1000mg Ashwagandha"? Prove it. cGMPs (21 CFR Part 111) require label claims to match reality. If you claim 500mg magnesium and the lab finds 320mg, you've got a misbranded product AND a manufacturer who's incompetent or lying.

Cost: $200–$600 per active ingredient.

That's It. The Big Three.

If you're pre-revenue and bootstrapped, do these three before selling. Not zero. Not "after the first 100 orders." These three. Period.


The Testing Timeline: When to Test What

Phase 1: Formulation / Bench Samples

Goal is confirmation, not certification. Test raw material identity (is this actually Ashwagandha or rice flour?), rough potency on candidate formulas, solubility/compressibility for tablets or liquids. Budget: $500–$800. Don't pay for full CoAs on formulas getting tweaked three more times.

Phase 2: Pilot Batch (100–500 Units)

The most important testing moment of your launch. Made on the production line — these results follow you to market. Test the full Big Three, start stability, dissolution if applicable. Budget: $1,500–$3,500. Catch a failure at 500 units, not 10,000.

Phase 3: First Full Production (1,000+ Units)

Verify that production scaled without drift. Repeat Big Three, raw material identity (don't skip this), schedule GMP audit if retail is the plan. Budget: $2,000–$5,000.

Phase 4: Ongoing / Every Lot

Microbial and potency on every lot. Heavy metals can shift to skip-lot (every 3rd–5th) after 5–10 clean data points with documented justification. Budget per lot: $500–$1,500.

Stability Testing: Don't Skip This

That expiration date on your bottle isn't decorative. It's a claim backed by data — or at least, it should be. Stability testing tells you how long your product actually holds its potency and stays safe under real storage conditions. Start it the day your pilot batch comes off the line.

Real-time stability runs 12–24 months (storing product at normal conditions and testing at set intervals). Accelerated stability runs 6 months at 40°C/75% relative humidity and gives you a 2-year shelf-life estimate you can use to get to market while real-time data collects.

Budget: $3,000–$8,000 for a full ICH stability study. I've seen brands put "Exp 2 Years" on labels based on pure vibes and wishful thinking. Don't be that founder. When a retailer asks for your stability data — and they will — "we just guessed" is not the answer that gets you shelf placement.


The Startup Testing Budget: Real Numbers

StageWhat You're TestingRealistic Budget
Formulation/BenchRaw material ID, rough potency$500 – $800
Pilot Batch (100–500 units)Full metals, microbial, potency, start stability$4,000 – $8,000
First Production (1,000+ units)Repeat Big Three, raw material verify, GMP audit prep$3,000 – $6,000
Ongoing Per LotPotency, skip-lot metals, full microbial$500 – $1,500
Annual MaintenanceGMP audit, method validation, stability pull-points$5,000 – $12,000

Year-One for a Single-SKU Launch: $10,000–$25,000.

If that number scares you, good. $15K in testing is dramatically cheaper than one recall, one lawsuit, or one lost retail deal because you couldn't produce a CoA. Testing is line-item #3 after manufacturing and packaging. If you can't afford the Big Three, you can't afford to launch.


What You CAN Defer vs. What You CANNOT Skip

CANNOT Skip — No Exceptions

TestWhy
Heavy metals (Pb, As, Cd, Hg)Consumer safety. FDA priority #1.
Microbial (APC, yeast/mold, pathogens)One bad batch kills a brand.
Potency/label claim verification21 CFR 111. Your label is a legal document.
Identity testing on incoming raw materialscGMP requirement. Know what's going in.

CAN Defer to Post-Revenue

TestDefer Until
Full pesticide residue panelPost-revenue. Use supplier CoA first, spot-check later.
Full solvent residue panelSame logic. Reputable suppliers do this already.
Full allergen panel (beyond required labels)Unless claiming "free from X."
Nutritional labeling full panelDatabase values initially. But if claiming "high in vitamin D," test it.
Shelf-life extension studiesStart base stability. Don't buy 36-month data until year 2.
Dissolution (non-critical products)Database references fine for standard vitamins.

The Gray Zone: GMP Certification

Not legally required for DTC. Required for Amazon, Whole Foods, any serious retailer. Plan year 2 for DTC-only; year 1 if retail is your strategy.


Phased Testing as You Grow

Seed Stage ($0–$100K ARR)

Big Three on every batch. Raw material identity (supplier CoAs for rest). Stability started. DIY management (you are QC). Budget: $10K–$25K/year.

Post-Revenue ($100K–$500K)

Skip-lot metals after 5 clean data points. Stability pull-points at 3, 6, 9, 12 months. Primary lab relationship. Part-time QC consultant (5–10 hrs/month). GMP cert prep if retail is coming.

Series A ($500K–$2M+)

Full 24-month stability. GMP certification complete. Full pesticide/solvent panels on incoming materials. Full-time QA/QC hire (or fractional at 20+ hrs/week). Method validation for proprietary actives. Competitor benchmarking. Annual FDA mock audit.

Enterprise ($2M+)

ISO 17025 lab partnership. Continuous stability. Full raw material program on every lot. Multiple QA/QC staff. Complaint trending and adverse event monitoring. Budget: $50K–$150K+/year.

Don't build Pfizer's quality system for your two-SKU protein powder. Phase it in.


How to Test Your Supplier's Raw Materials Before Committing

Common disaster: you find a supplier with an amazing price. You wire $15K. The material fails identity testing. Now you're fighting for a refund from another legal jurisdiction.

1. Request blind samples. Three samples from different lots. Send all to the lab. Consistent results = green flag. 95% purity on one, 78% on another = run.

2. Verify their CoA, don't trust it. Some CoAs are real. Some are Microsoft Paint. Send a sample to your lab and compare. Their CoA says 98% purity, your lab says 91%? Problem.

3. Audit the facility. $500–$1,000 for a third-party audit beats losing a $20K order. Firms specialize in this.

4. Test for the scary stuff on the first real order. Not just potency — heavy metals, pesticides (botanicals), residual solvents (extracts), adulteration (high-value ingredients).

5. Put testing in the contract. "Material failing independent testing returned at supplier's expense with full refund within 30 days." If they won't agree, walk.


Reverse engineering through lab testing is competitive intelligence, not espionage.

What you learn: Actual potency vs. label claims (if your competitor is under-delivering and you can truthfully hit label claim, that's a marketing advantage you can talk about without naming them), purity profiles and any contaminants lurking, fillers and excipients (tells you their manufacturing approach), and price-per-active-mg analysis to sharpen your value proposition.

How to do it: Buy 3+ units from different lot numbers. Potency profile + heavy metals screen. $500–$1,500 per competitor.

Ethical line: Testing competitors = legal. Publishing their results in your marketing = lawsuit. Say "Our product tests at 100% of label claim." Never say "Brand X tested at 62%."


Using Test Results in Your Pitch Deck and Marketing

Pitch Deck:

One slide: "All products tested for heavy metals, microbials, and label-claim potency by ISO-accredited third-party labs. CoAs available on request." Investor asks about regulatory risk: "We test every batch through independent ISO labs. Here are our latest results. Quality infrastructure is built ahead of retail." That answer beats 90% of supplement pitches.

Marketing (DTC):

  • "Lab-Verified" badge linking to actual posted CoAs
  • Social: "Every batch tested — here's batch #004" with real lab report photo
  • Email subject: "We tested our [product] for arsenic. Here's what happened."

Don't:

  • Make testing your entire brand identity (it's table stakes)
  • Publish competitor results (I mean it)
  • Claim "most tested" or "safest" without comparative data

Common First-Time Founder Mistakes

Mistake #1: Over-Testing. I knew a founder who ran 47 tests on a 200-unit multivitamin batch. $11K testing, $4K retail. Broke before launch. Fix: Big Three first. Add tests with specific reasons.

Mistake #2: Wrong Test Methods. "Test for Ashwagandha" without specifying the marker compound and method = garbage data and a $400 bill, then $600 to redo it with a lab that knows what they're doing. Different matrices need different sample prep — you can't run a gummy on a method validated for powder and expect usable numbers. Fix: work with a lab that actually knows supplements. Tell them your matrix, analytes, and expected concentration range upfront. If they can't answer basic questions about method suitability for your product type, they're not your lab.

Mistake #3: Choosing the Cheapest Lab. Range is "ISO 17025 accredited, FDA-inspected" to "guy with an HPLC in a strip mall." Fix: look for accreditation, proficiency testing participation, and ask their OOS investigation procedure. Good labs have a documented process. Bad labs say "we retest and send the passing number."

Mistake #4: Not Reading Your CoA. You see green checkmarks and file it. Six months later a retailer flags that a result was below the LOQ — your label claim isn't actually verified. Fix: learn LOQ, LOD. "ND" means "below detection limit," not necessarily zero. Call the lab and ask.

Mistake #5: Zero Documentation System. CoAs in Downloads next to "receipt-from-doordash-47.pdf." Can't find them when asked. Fix: day one, Google Drive, one folder per batch number. CoA, batch record, raw material CoAs, complaints. Ten minutes per batch.


Talking About Testing with Investors and Retailers

With Investors:

They care about risk. "We've built our quality program to mitigate the top three regulatory risks: contamination, misbranding, adulteration. Every batch tested for metals, microbials, and potency through ISO 17025 labs. Full batch documentation to raw material receipt. Quality infrastructure built for retail from day one."

With Retailers:

They care about THEIR liability. Come prepared with: Certificate of Liability Insurance ($1M minimum), GMP certification (NSF/USP/UL), batch-specific CoAs, written recall plan (1–2 pages fine at startup), adverse event procedure. Show up with all this and you've beaten 80% of brands who pitch them.


The LabQuotes Advantage for Startups

Most labs want ongoing contracts and minimums. When you're launching with one product, that conversation sucks.

No minimum orders. One heavy metals panel on one batch? Done. Nobody tells you it's too small.

Compare prices. Submit requirements once, get multiple quotes from accredited labs. Price differences can be 2–3x for identical specs. Without comparison, you'd never know.

Startup-friendly labs. Not every accredited lab wants small-brand work. LabQuotes connects you with the ones that do.

Real turnaround times. Filter by turnaround and read founder reviews. "The lab is running behind" is not a launch-day conversation you want.

I did it the hard way — Googled, called, overpaid 40%, got ghosted for 18 days. You can skip that part.

[Get Free Quotes from Accredited Supplement Testing Labs →]


When to Hire QA/QC vs. DIY

DIY Is Fine When:

1–3 SKUs, 2–4 runs/year, 1–3 suppliers, you review every CoA, and you've read some of 21 CFR Part 111.

You Need Help When:

4+ SKUs or 6+ runs/year, new product category (powders → gummies = different risks), retail partner requiring quarterly docs, an OOS investigation, or 5+ hours/week on testing tasks without being a quality pro.

OptionCostBest For
DIY + occasional consultant$2K–$5K/yearPre-revenue, 1–3 SKUs
Fractional QA/QC (5–10 hrs/week)$15K–$40K/year$250K–$1M, 3–10 SKUs
Full-time QA/QC hire$60K–$90K/year$1M+, 10+ SKUs, retail
Quality consultant retainer$2K–$5K/monthSeries A+, multi-category, pre-audit

Don't hire a $75K QC person at $200K revenue. Don't still be reviewing CoAs at 11pm when you're doing $800K with 12 SKUs.


Quick-Reference Checklist: Before Your First Bottle Ships

  • Heavy metals panel (Pb, As, Cd, Hg) — passing results in hand
  • Microbial panel (APC, yeast/mold, E. coli, Salmonella, Staph. aureus) — passing
  • Potency/label claim for every active — within ±10% of label claim
  • Raw material identity on incoming ingredients (or supplier CoAs with verify plan)
  • CoAs filed in an organized system (not Downloads folder)
  • Certificate of Liability Insurance active
  • Written recall plan (1–2 pages is fine)
  • Adverse event reporting procedure documented
  • Stability study initiated (or firm calendar date)
  • Label checked against test results (don't print 10K labels for 1000mg if tests show 920mg)
  • Supplier contract includes testing-failure return/refund clause

FAQ

Q: Can I just use my manufacturer's CoA? No. 21 CFR Part 111 requires independent identity verification. Relying on the manufacturer's CoA is like asking a student to grade their own homework. Retailers and FDA won't accept it as independent.

Q: How long does testing take? Standard panels: 5–10 business days. Rush: 2–5 days at 50–100% surcharge. Stability: 6 months accelerated, 12–24 months real-time.

Q: What if my batch fails a test? Don't panic. Don't retest three times hoping for a different number — labs flag suspicious retesting and it doesn't fix the root problem. Step one: investigate with your manufacturer. Was it the raw material? A processing error? Cross-contamination on the line? Depending on severity and whether the result is truly out of spec vs. borderline within regulatory limits, you may need to rework the batch, destroy it, or document a risk-based justification. This exact scenario is why having a QA consultant on call is worth every penny. They've seen a hundred OOS investigations and won't freeze up like you will your first time.

Q: Do I need to test every batch forever? Microbial: every batch, no exceptions. Heavy metals: skip-lot (every 3rd–5th) after 5–10 clean lots, documented in SOP. Potency: every batch for label-claimed actives.

Q: What lab certifications should I look for? ISO 17025 accreditation. Proficiency testing participation (LGC, AOCS, USP). Labs that do pharma work alongside supplements tend to have higher standards.

Q: Amazon-specific testing requirements? Amazon wants: third-party CoAs from ISO 17025 labs for metals and microbial, GMP certificate (NSF/USP/UL/SAI Global), product images with full label, Letter of Guarantee. Have it all ready before listing — they're aggressive about suspensions.

Q: US labs or overseas? US-based ISO 17025 labs. FDA wants labs they recognize and audit. US retailers expect US results. Overseas savings aren't worth the regulatory and credibility risk.

Q: Different testing for gummies and liquids? Yes. Higher water activity = different microbial risks (mold). Different sample prep needed — sugar matrix in gummies interferes with some methods. Talk to your lab about method suitability for your matrix.


The Bottom Line

Testing isn't Instagrammable. It won't go viral on TikTok. But it's the difference between a brand that exists in five years and a cautionary tale in someone else's blog post.

Do the Big Three before you sell a single unit. Phase everything else in with revenue. Document everything. Get quotes and compare — it costs nothing and might save thousands.

Get Free Quotes from ISO-Accredited Supplement Testing Labs →


Questions? Drop them in the comments. I answer everything — especially the dumb ones. Those are usually the expensive ones.

Ready to get your products tested?

Build a basket of the tests you need and compare quotes from ISO 17025–accredited labs in one place. Free to start.

Get lab quotes

More guides

Cost & Pricing

How Much Does Supplement Testing Actually Cost?

Amazon & Marketplace

Amazon Supplement Compliance: Don't Get Delisted

FDA & GMP

The "Oh Crap, The FDA Is Calling" Guide to 21 CFR 111 Testing Requirements

Getting Started

How to Find a Supplement Testing Lab — The Complete Guide

Test Methods

Heavy Metal Testing for Supplements: Methods, Costs, and What You're Actually Testing For

Test Methods

Shelf-Life and Stability Testing: How Long Does Your Supplement Actually Last?

Manufacturing

Contract Manufacturer Testing: Why 'They Handle It' Is the Most Dangerous Phrase in Supplements

Specialized

Sports Nutrition Banned Substance Testing: NSF, Informed Sport, and BSCG Explained

Getting Started

How to Read a Certificate of Analysis: What the Numbers Actually Mean

Test Methods

Probiotic Testing: CFU Counts, Strain Verification, and Shelf-Life Stability

Specialized

CBD Testing: Potency, THC Limits, and the Tests That Keep Your Product Legal

Compliance

Importing Supplements: The Testing and Customs Documentation You Need to Clear the FDA

Manufacturing

Private Label Supplement Testing: Why Your Manufacturer's COA Isn't Enough

Compliance

Prop 65 Supplement Testing: Don't Wait for the Lawsuit Letter

Manufacturing

How to Source Ingredients That Actually Pass Prop 65 Testing

Compliance

California vs. Federal Supplement Testing: Why FDA Compliance Isn't Enough

Specialized

Mushroom Supplement Testing: Is It Actually Mushrooms or Just Grain Powder?

Getting Started

Your Supplement Failed Testing. Now What?

Selling Online

How to Use Your Test Results in Marketing (Without Getting an FDA Letter)

Selling Online

Amazon Supplement Reinstatement: How to Get Your Listing Back After a Compliance Removal

Specialized

Gummy Vitamin Testing: The Sticky Truth Nobody Tells You

Test Methods

Is Your Magnesium Glycinate Actually Magnesium Oxide? How to Test What's Really in the Bottle

Getting Started

How to Test Your Supplement Before Selling (First Batch Checklist)

FDA & GMP

Supplement Finished Product Testing: The GMP Release Checklist

Getting Started

Are Your Supplier's COAs Real? How to Verify Raw Material Testing

Compliance

5 FDA Supplement Regulations You're Probably Violating Right Now

Manufacturing

How to Switch Supplement Testing Labs Without Screwing Up Your Compliance

Getting Started

Do I Actually Need to Test My Supplements? The Honest Answer

Free Resources

21 CFR 111 GMP Compliance Checklist — Free PDF Download

Free Resources

State of Supplement Testing 2026 — Real Data From Thousands of Quotes

Free Resources

Free Supplement Specification & COA Templates

Selling Online

Amazon Supplement Approved Lab List — What Labs Amazon Actually Accepts

Selling Online

How to Upload a COA to Amazon Seller Central — Step by Step

Getting Started

Supplement Lab Comparison — Eurofins vs SGS vs Intertek vs ALS vs Independent Labs

Test Methods

Allergen & Gluten-Free Testing for Supplements — ELISA Methods

Ingredient Testing

Ashwagandha Testing: Withanolides, Root Auth, Heavy Metals

Ingredient Testing

B-Complex Supplement Testing: Simultaneous B-Vitamin Potency HPLC Panel

Ingredient Testing

Beetroot Nitrate Testing: Quantifying Active, Label Claims, Metals

Ingredient Testing

Berberine Supplement Testing: HPLC Purity, Adulteration, Identity

Test Methods

Botanical Identity Testing — HPTLC, Microscopy, DNA Barcoding

Specialized

Collagen Supplement Testing — Amino Acid Profile Verification

Ingredient Testing

Creatine Supplement Testing: Purity, Impurities by HPLC, and Creapure Verification

Test Methods

Disintegration & Dissolution Testing for Supplements — USP <2040>

Test Methods

DNA Barcoding Supplement Identity: Species Authentication by qPCR

FDA & GMP

DSHEA Explained for Supplement Brands

Ingredient Testing

Elderberry Supplement Testing: Anthocyanin Content, Identity, and Microbial Safety

Specialized

Electrolyte Powder Testing — Sodium, Potassium, Magnesium Verification

Test Methods

Ethylene Oxide Testing Supplements: EtO and 2-Chloroethanol by GC-MS

FDA & GMP

FDA Warning Letters for Supplements -- Testing Violations

FDA & GMP

Form 483 Response Guide for Supplement Companies

Ingredient Testing

Ginseng Testing: Ginsenoside Profile by HPLC, Species Authentication, and Pesticide Risks

Ingredient Testing

Glucosamine Chondroitin Testing: Potency and Adulteration Detection

Test Methods

Glyphosate Testing Supplements: LC-MS/MS Residue Detection, Claims

Amazon & Marketplace

GMP Certificate for Amazon -- Do You Need One?

Specialized

Greens Powder Testing — Heavy Metals, Pesticides, Nutritional Panel

Getting Started

How to Prepare Supplement Samples for Lab Testing — Shipping, Packaging, Chain of Custody

Test Methods

HPLC Potency Testing for Supplements — How It Works

Test Methods

ICP-MS vs AAS for Supplement Heavy Metal Testing — Which Method?

Ingredient Testing

Iron Supplement Testing: ICP-MS Potency, Form Verification, Disint

Getting Started

ISO 17025 for Supplement Testing, Explained

Getting Started

ISO 17025 vs Non-Accredited Labs: Why It Matters for Supplement Testing

Ingredient Testing

L-Theanine Supplement Testing: HPLC Purity, L vs D Enantiomer Verification, and Identity

Compliance

Supplement Label Claim Substantiation — Testing Every Word on Your Bottle

Ingredient Testing

Maca Root Testing: Identity, Macamide Markers, and Heavy Metal Screening

Test Methods

Melamine Testing Supplements: Detecting Nitrogen Spiking by LC-MS/MS

Specialized

Melatonin Supplement Testing — HPLC Content Verification

Test Methods

Microbial Limits Testing for Supplements

Test Methods

Microcystin Testing Algae Supplements: Cyanotoxin ELISA and LC-MS/MS

Ingredient Testing

Multivitamin Testing: Multi-Analyte Potency, Label Overage

Test Methods

Mycotoxin Testing Supplements: Aflatoxins, Ochratoxin A, Fumonisins

Test Methods

Nitrosamine Testing Supplements: NDMA/NDEA Detection by LC-MS/MS

Ingredient Testing

NMN Supplement Testing: Purity by HPLC, NMN vs NR Verification, and Regulatory Status

Test Methods

Non-GMO PCR Testing for Supplements — How It Works

Specialized

NSF Certified for Sport vs Informed Sport — Which Testing Program?

Specialized

Omega-3 & Fish Oil Supplement Testing — EPA, DHA, TOTOX

Compliance

Organic Supplement Certification — Testing Requirements

Getting Started

7 Supplement Tests You're Probably Overpaying For (And How to Fix It)

Test Methods

PAH Testing Supplements: Polycyclic Aromatic Hydrocarbons by GC-MS

Test Methods

Pesticide Testing for Supplements — Multi-Residue Screen Guide

Ingredient Testing

Pre-Workout Supplement Testing: Banned Stimulants and Label Accuracy

Ingredient Testing

Prenatal Vitamin Testing: Folate Form, Heavy Metal Safety, Potency

Ingredient Testing

Protein Powder Testing: Heavy Metals, Amino Spiking, and Real Protein Content

Ingredient Testing

Psyllium Fiber Testing: Identity, Microbial Screening for Salmonella, and Water Activity

Test Methods

Residual Solvent Testing for Supplements — USP <467>

Ingredient Testing

Saw Palmetto Testing: Fatty Acid Profile, Adulteration, Identity

Ingredient Testing

Sea Moss Testing: Iodine Content, Heavy Metals, Species Auth

Compliance

Skip Lot Testing for Supplements — When You Can Reduce Testing

Ingredient Testing

Spirulina Chlorella Testing: Microcystin, Heavy Metals, Micro

Compliance

Structure/Function Claims Testing Requirements

Compliance

Supplement Facts Panel Testing Requirements

Getting Started

Third-Party Supplement Testing: Why It's Non-Negotiable

Ingredient Testing

Turmeric Curcumin Testing: Potency, Lead Chromate, Identity

Test Methods

USP 2232 Heavy Metals Testing Explained

Ingredient Testing

Vitamin C Testing: Ascorbic Acid HPLC Potency, Degradation, Stability

Specialized

Vitamin D Potency Testing — HPLC vs LC-MS/MS Methods

Test Methods

Water Activity Testing for Supplements — Why It Matters