When claims are no longer enough: in a highly competitive health and beauty market, many brand owners invest heavily in marketing, only to fall short because they lack clear evidence of credibility. Listing an extract on the label no longer proves quality to trade partners or regulators. What you need is a pair of documents, the COI (Certificate of Ingredients) and the COA (Certificate of Analysis). Used together, they show your standards in a way that others can verify.
What Is a COI? Meaning and Definition
COI stands for Certificate of Ingredients (also called a certificate of composition or an ingredient declaration). It is a document issued by the manufacturer that lists every ingredient in a product formula and the amount of each. Brand owners request it from their manufacturer.
A note on the COI meaning: in other fields, COI often refers to something else entirely, such as a certificate of insurance or a conflict of interest. This article is about the COI document used for cosmetics, dietary supplements and extracts.
What Does a COI Contain?
Formats differ between manufacturers, but a useful COI document usually includes:
- Product name and formula version: so you know the document matches the formula actually produced.
- Every ingredient: listed by standard names, such as INCI names for cosmetics.
- The amount of each ingredient: usually as a percentage by weight, or as ranges when the manufacturer wants to protect the formula.
- The function of each ingredient: for example active ingredient, preservative, humectant or texture agent.
- Details of key raw materials: such as CAS numbers, grades or suppliers.
- Date, approver and signature: confirming who is responsible for the information.
COI and the INCI List
INCI stands for International Nomenclature of Cosmetic Ingredients, the international naming system for cosmetic ingredients. It gives each ingredient the same name wherever the product is sold: niacinamide is listed as Niacinamide, and Centella asiatica extract as Centella Asiatica Extract, in many markets. Cosmetic labels list ingredients by INCI names, generally in descending order of amount, following each country’s rules.
A COI that uses INCI names helps the manufacturer, the brand owner, the laboratory and regulators understand the formula in the same way, and makes it easier to check that the INCI list on the label matches the real formula.
Why COI and COA Matter
COI (the map) + COA (the proof) = transparency
Imagine setting out on a journey through a forest, which stands for the manufacturing process. The COI is the map that tells you what is in your backpack and how much of each item you are carrying. The COA is the photo taken when you come out of the forest, proving that you still have those items and that they work.
- COI (Certificate of Ingredients): a document that shows the formula and all the ingredients in your product, including which extracts are used and at what percentage.
- COA (Certificate of Analysis): the manufacturer’s certificate for each lot, backed by test results from a laboratory. It shows whether the extracts listed in the COI are actually present in the finished product and whether the product meets its quality specifications.
| COI | COA | |
|---|---|---|
| Answers | What is in the formula, and how much? | Did this lot meet its quality criteria? |
| Issued by | The manufacturer or formula owner | The manufacturer, based on a laboratory Test Report |
| Issued when | When a formula is set or changed | For every production lot |
| Used for | Notification, labeling, and choosing reference standards for testing | Product release, incoming checks and export |
Why Use COI and COA Together?
Having a COA without a COI, or a COI without results from an independent laboratory, is a risk that brands should avoid:
- Accuracy: When you send your COI to a laboratory such as Visbio, our scientists use it as the basis for selecting the most appropriate reference standards (standard markers). Without a COI, the lab may be looking for a needle in a haystack, or the results may be less accurate than they should be.
- Cross-check: Using both documents lets you check your manufacturer. If the measured value is far below what the COI implies, that is a warning sign that protects your money and your reputation.
A worked example: the COI states 5% turmeric extract, and the extract’s specification states 10% curcuminoids. The expected curcuminoid content of the product is therefore about 0.5% (5% × 10%). If the laboratory finds only 0.05%, a tenth of the expected level, the cause should be investigated with the manufacturer. Before drawing conclusions, consider other factors too, such as degradation during production or storage.
Reading the COI for Herbal Extracts
For herbal extracts, the figures in a COI may not tell you the key compound content directly. Always read these details together:
- Drug-extract ratio (for example 10:1): how much herbal material was used per part of extract. It does not state the key compound content of the extract.
- Standardized extract: an extract with a stated key compound content, such as 95% curcuminoids, which can be verified by HPLC.
- Solvent and carrier: many cosmetic extracts are sold as solutions in glycerin or glycols, so “5% extract” in a formula may contain far less actual extract. Powdered extracts may use maltodextrin as a carrier.
- Marker compound: state clearly which compound will be used to confirm the extract’s quality, so the laboratory can prepare the right reference standard from the start.
Common COI Mistakes
- An outdated COI that no longer matches the formula actually produced after a reformulation.
- Trade names instead of INCI names, which makes it harder to check labels and choose reference standards.
- Percentages that do not add up to 100%, or missing solvents and carriers for extracts.
- No version number or date, so the COI cannot be matched to production lots.
- An ingredient included for a claim, with no measurable key compound to confirm it.
These mistakes can be fixed when you request the documents, and fixing them helps laboratory testing start quickly and on target.
Using the COI When You Send Samples for Testing
When you want to confirm that a product contains its key compounds as formulated, working with a laboratory usually follows these steps:
- Send information before samples: share the COI, or the necessary composition details, together with the specification or COA of the key extracts.
- Choose what to measure: the team identifies the key compounds that can be measured and that match what you want to claim, and confirms whether a method and reference standards are available.
- Analyze the product: the key compound content of the product is measured by HPLC against reference standards. See the principle in What Is HPLC?
- Compare with the COI: the measured values are compared with the values calculated from the COI and reported in a Test Report that the manufacturer can use for the COA. See the full process in COA Testing.
How to Request a COI from Your Manufacturer
- Sign a non-disclosure agreement (NDA) first if the manufacturer is concerned about revealing the formula.
- Ask for a COI with a formula version number, and request a new one whenever the formula changes.
- If the manufacturer gives ranges, ask for exact values at least for the key compounds you plan to claim.
- Ask for the raw material COAs of key ingredients, so you know the key compound content of the materials actually used.
- Keep the COI and COA together in your product file for future reference.
How to Use COI and COA Beyond Thai FDA Notification
- Thai FDA notification: cosmetic notification requires the formula’s ingredients, and an accurate, current COI helps you submit information that matches the real product.
- Export (Global Gateway): Trade partners in Europe and the United States want more than a single sheet of paper. They look for consistency between the COI (what you say is inside) and the COA (what is actually found). When the two match, your product earns a higher level of confidence.
- Product information file: in the European Union, for example, cosmetics need a Product Information File (PIF) that includes the qualitative and quantitative composition of the formula, so the COI is an essential starting point.
- Quality control (QC): Use them as the baseline for controlling every production lot, so that a customer who buys your product three years from now receives the same quality as your very first lot.
- Labeling: Use the COI to check that the ingredient list on your label matches the real formula, reducing the risk of labeling errors.
Frequently Asked Questions About the COI
What does COI stand for?
In cosmetics, supplements and extracts, COI stands for Certificate of Ingredients: a document listing the ingredients and amounts in a product formula. It is also called a certificate of composition.
What is the difference between a COI and a COA?
A COI states what the formula contains and how much. A COA certifies that each production lot meets its criteria, based on laboratory test results.
Who issues a COI?
The manufacturer or formula owner. Brand owners who use contract manufacturers request the COI from them.
Do I have to disclose my full formula to the laboratory?
The laboratory needs only the information required to choose the test method and reference standards, such as the key compounds and their approximate levels, and a confidentiality agreement can be signed.
What is an INCI name?
The international name of a cosmetic ingredient, used on labels and in documents such as the COI so that everyone understands the formula in the same way.
Does 5% extract in a COI mean 5% key compound?
No. The key compound content depends on the concentration of the key compound in the extract and on any solvent or carrier. Check the extract’s specification or COA, and confirm it by analysis.
When should a COI be updated?
Whenever the formula changes, including when a key raw material or its supplier changes.
Conclusion
Understanding and managing the COI and COA together is the first step in moving from online seller to brand owner with international standards. At Visbio, we are ready to be a key piece of that puzzle, proving the facts through scientific testing so that your document pair truly leads to success.
Related reading
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