Creatine Monohydrate Purity: What 99.9% Actually Means
When a creatine label says 99.9% pure, it means the remaining 0.1% is not creatine monohydrate. That fraction is small, but knowing what it might contain — and how manufacturers are supposed to keep it there — is worth understanding before you buy.
What is in the other 0.1%?
Creatine monohydrate is synthesised from two precursors: sarcosine and cyanamide. Both reactions can leave residues if the process is not well controlled. The two impurities that regulators and quality labs look for most closely are dicyandiamide (DCD) and dihydrotriazine.
Dicyandiamide is a by-product of cyanamide and, in poorly manufactured batches, can be present at levels that attract attention. It is not acutely toxic in small amounts, but it is not something you want to be consuming daily over months or years when it should not be there at all. Dihydrotriazine is a cyclisation product that forms under certain reaction conditions; it is less commonly discussed but is listed in pharmacopoeial monographs as a controlled impurity.
A 99.9% purity specification sets the upper limit on this combined residual fraction. At 5g per day — the serving size in our micronised creatine powder — a 0.1% residual means roughly 5mg of non-creatine material per dose. Whether that matters depends entirely on what those 5mg actually are.
Why the source country matters
Most creatine monohydrate worldwide is synthesised rather than extracted from food. Manufacturer quality varies considerably. Independent testing has found that some lower-cost batches, particularly from facilities without robust quality programmes, carry dicyandiamide levels well above the trace amounts implied by a 99.9% claim. A purity figure on a label is only as reliable as the testing behind it.
GMP — Good Manufacturing Practice — is the standard that governs how pharmaceutical and supplement ingredients should be made. A GMP facility is required to test incoming raw materials, validate its synthesis process, and document results batch by batch. Our micronised creatine powder is made in the UK to GMP standards. That does not make it immune to variation, but it means there is a documented quality system in place, not just a number printed on a bag.
What micronisation does and does not do
Micronised creatine has been milled to a finer particle size than standard creatine monohydrate — typically under 200 microns. This improves how it disperses in water and reduces the gritty texture some people notice with coarser grades. If you have ever mixed creatine and found it settling to the bottom of the glass, micronisation reduces that significantly. Our page on micronised versus standard creatine covers more detail on this.
What micronisation does not do is change the chemical composition. It is a physical process. A batch that is 99.9% pure before milling is still 99.9% pure after it. A batch with elevated dicyandiamide before milling has elevated dicyandiamide after it. Purity is set at the synthesis stage, not the milling stage.
Single-ingredient products and adulteration risk
There is a separate issue that purity specifications do not fully address: deliberate or accidental adulteration. This is less about synthesis by-products and more about what else ends up in the finished product. Proprietary blends, pre-workouts and flavoured creatine products contain multiple ingredients, which means more places for unlisted substances to appear — whether through cross-contamination, labelling error or, in the worst cases, intentional addition.
A single-ingredient, unflavoured product has a simpler matrix. There is only one thing in the tub, which makes any deviation from specification easier to detect. Why we sell unflavoured supplements covers this reasoning in more detail, but the short version is that simplicity is itself a quality control measure.
What we can and cannot tell you about our own testing
Our creatine monohydrate is made in the UK to GMP standards. We do not make a specific public claim that we test each batch for dicyandiamide or dihydrotriazine by name, because we have not published that data. What GMP manufacturing requires is that the synthesis process is controlled and validated, which is the upstream point at which these impurities are managed.
If you are buying creatine and purity documentation matters to you — for sport, for professional reasons, or simply because you want to know — asking a supplier for a certificate of analysis (COA) is reasonable. A COA from a reputable third-party lab will list the assayed purity and any tested impurities, not just a specification claim from the manufacturer.
Powder or tablets: does format affect purity?
If you prefer a measured dose without scooping, creatine powder versus tablets is worth reading. From a purity standpoint, the same principle applies: the relevant variable is the source and manufacturing standard of the creatine itself, not the format it comes in. Our tablets contain 1,000mg of creatine monohydrate per tablet; three tablets delivers 3g of creatine per day. Creatine increases physical performance in successive bursts of short-term, high-intensity exercise. The beneficial effect is obtained with a daily intake of 3g of creatine.
The 99.9% figure is not marketing fiction. It is a genuine specification, and at well-run GMP facilities it reflects what the product actually contains. The questions worth asking are who set that figure, how it was verified, and what the manufacturing process looks like behind it.
