How to Check Creatine Purity: Contaminants, Fillers, and Label Claims

The label on a creatine supplement tells you what the manufacturer wants you to know. Purity testing tells you what is actually in the container. The gap between these two can range from negligible (in high-quality products) to significant (in poorly manufactured ones). This guide covers what contaminants to look for, how to read a Certificate of Analysis, and what signals distinguish quality products from questionable ones.

Common Contaminants in Creatine

Creatine monohydrate is produced through chemical synthesis, typically reacting sarcosine with cyanamide. This reaction produces creatine as the primary product along with several byproducts whose presence and concentration depend on reaction conditions, raw material quality, and purification procedures.

Dicyandiamide (DCD)

DCD is a dimer of cyanamide that forms when cyanamide molecules react with each other instead of with sarcosine. Its presence indicates incomplete or poorly controlled reaction conditions. Creapure specifications limit DCD to below 50 parts per million (ppm). Some generic products have been found with DCD levels exceeding 200 ppm. DCD is generally considered to have low acute toxicity, but its presence is a marker of manufacturing quality.

Dihydrotriazine (DHT)

DHT is a heterocyclic compound that can form during creatine synthesis. It is the contaminant of greatest regulatory concern because of its structural similarity to triazine herbicides. Creapure limits DHT to below 3 ppm. Products with DHT levels significantly above this threshold indicate substandard manufacturing or purification. While no direct human toxicity data exist at the levels found in creatine supplements, the precautionary approach favors minimizing exposure.

Creatinine

Creatinine is the cyclization product of creatine. It is naturally produced in the body and excreted by the kidneys. In the context of a creatine supplement, elevated creatinine levels indicate either incomplete purification during manufacturing or degradation during storage (exposure to moisture, heat, or extended shelf time). Creatinine is not harmful, but high levels mean the product contains less active creatine than the label suggests.

Heavy Metals

Arsenic, lead, mercury, and cadmium can be present in trace amounts depending on the raw materials and equipment used in manufacturing. These are regulated at very low levels across all supplement categories. California's Proposition 65 sets particularly strict thresholds. Most reputable creatine manufacturers test for heavy metals, but the availability of test results to consumers varies.

Reading a Certificate of Analysis

A Certificate of Analysis (CoA) is a document issued by the manufacturer or a third-party laboratory that reports the results of testing on a specific batch of product. For creatine supplements, a quality CoA should include:

1. Product identification: The product name, batch or lot number, and manufacturing date.
2. Assay (purity): The percentage of the product that is creatine monohydrate. High-quality products report 99.9% or higher.
3. DCD level: Reported in ppm. Below 50 ppm is the standard for premium quality.
4. DHT level: Reported in ppm. Below 3 ppm is the Creapure standard.
5. Creatinine level: Reported in ppm or as a percentage. Below 100 ppm indicates good quality and freshness.
6. Heavy metals: Individual values for arsenic, lead, mercury, and cadmium, or a total heavy metals figure.
7. Microbial testing: Total plate count, yeast and mold, coliforms, and specific pathogens (E. coli, Salmonella, Staphylococcus).
8. Testing method: HPLC for purity and contaminant quantification is the preferred method.
9. Laboratory identification: For third-party CoAs, the name and accreditation of the testing laboratory.

Red Flags on a CoA

• No batch or lot number (cannot be linked to a specific production run).
• Results listed as "conforms" or "pass" without numerical values.
• No testing method specified.
• The manufacturer issued the CoA with no third-party verification.
• The document is undated or very old relative to the product's manufacturing date.

What the Label Should Tell You

Under FDA regulations (21 CFR Part 101), the supplement facts panel must list all active ingredients and their amounts per serving. For a straightforward creatine product, the panel should show:

• Creatine monohydrate as the active ingredient.
• The amount per serving in grams (typically 5 grams).
• Other ingredients, which should be minimal in a plain creatine product. Acceptable other ingredients include anti-caking agents like silicon dioxide.

Label Warning Signs

• Proprietary blends containing creatine: If creatine is part of a proprietary blend, the individual amount of creatine is not disclosed. You cannot know if you are getting an effective dose.
• Long ingredient lists: A pure creatine product should have one active ingredient. Multiple active ingredients dilute the creatine content per serving.
• Vague form descriptions: The label should specify "creatine monohydrate" rather than just "creatine." Without the form specified, you cannot evaluate the product against the research base.
• Unsubstantiated claims: Claims like "10x absorption" or "no loading needed" without citing specific peer-reviewed studies are marketing, not science.

How Consumers Can Verify Purity

Request the CoA

Contact the manufacturer and ask for the Certificate of Analysis for the specific batch you purchased (identified by the lot number on your product). Reputable companies will provide this document. Companies that refuse or do not have batch-specific CoAs are a concern.

Check Third-Party Databases

USP, NSF, and Informed Sport maintain searchable databases of certified products. You can verify whether a product's certification is current and legitimate rather than relying on a logo that may be outdated or fraudulently applied.

Independent Consumer Testing

Services like ConsumerLab.com and Labdoor purchase products at retail and publish independent test results. While these services require a subscription, they provide objective data on products tested under real market conditions rather than manufacturer-selected samples.

Visual and Physical Indicators

While not definitive, some physical properties can indicate quality issues:

• Pure creatine monohydrate is a white, odorless powder. Yellowish tints or strong odors may indicate impurities or degradation.
• Clumping or hardening in the container suggests moisture exposure, which accelerates conversion to creatinine.
• Packaging without a sealed inner barrier (foil seal, desiccant packet) is more susceptible to moisture intrusion.

The Purity Hierarchy

Level	What It Means	Consumer Confidence
Creapure + third-party certified + batch CoA	Premium raw material, independent verification, full traceability	Highest
Third-party certified (NSF/USP/Informed Sport)	Independently verified potency and purity	High
Creapure sourced, no third-party certification	Quality raw material, but finished product unverified	Moderate-High
Generic with manufacturer CoA available	Self-reported quality data, some transparency	Moderate
No certification, no CoA, unknown source	No independent quality verification	Low

Practical Guidance

Most consumers do not need pharmaceutical-grade analytical verification of their creatine. A product from a reputable brand with at least one third-party certification provides reasonable quality assurance. The minimum bar for an informed purchase is knowing the form (creatine monohydrate), the dose per serving (ideally 5 grams), and that the product has been independently tested.

For those willing to invest slightly more time, requesting a CoA from the manufacturer and cross-referencing it with the lot number on the product adds meaningful confidence. This is especially prudent for products purchased from online marketplaces where counterfeit and gray-market supplements are documented concerns.

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