Creatine to creatinine: the reaction behind every failed gummy test
Creatine does not spoil, get contaminated or go rancid. It quietly folds in on itself and becomes creatinine — a compound with no biological activity at all. Water, heat and time drive that reaction, and a gummy is the one format that applies all three. Here is the actual chemistry, with the published numbers.
Affiliate disclosure: GummyGains is reader-supported. The commercial links on this page point to Create, our current verified pick — if you buy through one we may earn a commission at no extra cost to you. Nothing in the chemistry below changes depending on what you buy, and the published results we cite include a round that Create failed. Full policy.
The headline number: creatine monohydrate powder shows no measurable degradation after three years at room temperature or at 40 °C. The same molecule in water at pH 3.5 loses 21% in three days at 25 °C. Pectin gummies are manufactured at pH 2.8–3.5 and cooked at 85–95 °C. That gap between the two numbers is the entire story of why gummies fail label-claim tests and powders do not.
What the reaction actually is
Creatine is not broken apart by anything external. It performs an intramolecular cyclization: one end of the molecule attacks the other, a molecule of water is expelled, and the open chain closes into a ring. The ring is creatinine.
Three things about this matter to you as a buyer:
- It is one-way. Under any condition you will encounter, creatinine does not turn back into creatine. Degraded product cannot recover on the shelf or in your stomach.
- It needs no help. There is no oxygen, no light and no microbe required. This is not spoilage. A sealed, sterile, perfectly clean gummy degrades on exactly the same schedule as a dirty one.
- Creatinine does nothing. It is biologically inert as a supplement ingredient — your kidneys filter it out. It is not poisoning you. It is simply not the thing you paid for.
Your body runs this same reaction on purpose. Roughly 1–2% of the creatine stored in your muscle converts to creatinine every day and leaves in your urine, which is why you have to keep taking it. The chemistry in a jar is the chemistry in a muscle; only the rate differs.
The three levers: water, heat, time — with pH as the dial
The cyclization expels a water molecule, so it is strongly affected by how much water is around for it to happen in. It is a chemical reaction, so it obeys Arrhenius temperature dependence. And it accumulates, so it is a function of how long the product has existed.
The fourth variable is pH, and it behaves in a way most people find counterintuitive. The International Society of Sports Nutrition's position stand on creatine states the rule plainly: the conversion happens faster the lower the pH and the higher the temperature. Acid accelerates it.
The exception that saves your dose: below roughly pH 2.5, the relevant amide group becomes protonated and the cyclization is blocked outright. Stomach acid sits well below that line. This is why swallowing creatine works at all, and why "it turns to creatinine in your stomach" — a claim invented to sell alternative creatine forms — is backwards. Transit through the gut converts a negligible amount regardless of how long it takes.
So the danger zone is the middle: acidic enough to accelerate the reaction, not acidic enough to shut it down. That window is roughly pH 3 to pH 6. Read that range again, then read the next section.
Powder: effectively inert for years
Published stability work on creatine monohydrate powder found creatinine below the 67 ppm limit of quantification after more than three years of storage at room temperature and at 40 °C (104 °F). Only under deliberately abusive conditions — 44 months at 60 °C, which is 140 °F — did creatinine become measurable, at 106 ppm. That is 0.01%.
Crystalline creatine monohydrate is one of the more boringly stable compounds in the supplement aisle, on one condition: it must stay dry enough not to reach deliquescence, the point at which the crystal starts absorbing enough atmospheric moisture to dissolve in it. Keep the lid on and the scoop dry and a tub of powder is chemically the same next year.
Water: the same molecule, a completely different timescale
Dissolve it and the picture inverts. Measured degradation of creatine in aqueous solution after three days at 25 °C:
| pH of the solution | Creatine lost in 3 days at 25 °C |
|---|---|
| 5.5 | 4% |
| 4.5 | 12% |
| 3.5 | 21% |
Degradation in solution tracks pH rather than concentration — mixing it weaker does not protect it.
This is the origin of the old advice not to pre-mix creatine and leave it in a bottle. Over an afternoon the loss is trivial. Over three days in a slightly acidic flavoured drink it is a fifth of your dose.
Why a gummy pulls all three levers at once
Now put the manufacturing process next to the chemistry.
A pectin gummy only gels in a narrow acid window. Manufacturing guidance for high-methoxyl pectin specifies a target pH of 2.8 to 3.5, with 3.0 to 3.2 typical for balanced texture. The pectin itself is activated by cooking at 85 to 95 °C (185–203 °F), and the slurry is held at 75 to 80 °C while it is deposited into moulds.
Line that up against the table above and the problem is obvious. The acid that makes a pectin gummy set is the acid that accelerates creatine cyclization, and it lands just above the pH 2.5 floor where protonation would have protected it. The heat that activates the pectin is heat applied directly to dissolved creatine. And then the finished product sits in a warehouse, a delivery van and a kitchen cupboard for months.
| Format | Water present | Heat applied to dissolved creatine | Acidified | Months on a shelf |
|---|---|---|---|---|
| Powder in a tub | No | No | No | Yes — but inert without the other three |
| Stick pack | No | No | No | Yes — same |
| Capsule | No | No | No | Yes — same |
| Gummy | Yes | Yes, 85–95 °C | Yes, pH 2.8–3.5 | Yes |
This is a property of the format, not an accusation against any particular brand. Every pectin gummy on the market is made roughly this way, because that is what makes a pectin gummy.
The water-activity finding that breaks the usual intuition
Here is the objection a food scientist would raise, and it is a good one: a gummy is not a solution. It is a semisolid with much of its water bound up in a gel network and in sugar. Water activity, not water content, is what drives reactions — and in most food systems, dropping water activity below about 0.7 causes reaction rates to fall off sharply, a dilution effect that is the basis of shelf-stable food design.
A 2009 study in Drug Development and Industrial Pharmacy tested exactly this, across water activities from 0.31 to 0.983 at 4, 23 and 35 °C. Its finding: creatine degradation did not exhibit that dilution effect. The rate did not drop off around aw 0.7 the way microbial growth and other chemical reactions in semisolid food matrices do. Half-life fell on a straight line against water activity on a semilog plot at every temperature, with no protective cliff. The authors noted that pH and increased viscosity together could not fully explain the rate changes they saw.
In other words, the intuition that "it's a gummy, it's low-moisture, it'll be fine" is a reasonable inference from how most food chemistry behaves — and for creatine specifically, it does not hold. Degradation followed first-order kinetics with an activation energy of about 20 kcal/mol at higher water activity, rising to 23 kcal/mol below aw 0.68. A gummy is a slower environment than a glass of water. It is not the safe harbour a candy's texture implies.
A 2025 paper in Food Research International stress-tested commercial creatine across 60–200 °C, UV exposure, pH 3, 8 and 13, and three beverage matrices, using FTIR and high-resolution mass spectrometry. It found temperature the single most significant factor affecting stability, and identified degradation products beyond creatinine — though notably those extra products appeared at alkaline pH and not at acidic pH. For gummies, which live on the acid side, creatinine remains the relevant product; heat remains the relevant lever.
Creatinine is not a contaminant. That distinction matters.
This is the single most common confusion in this category, and it is worth being precise about, because two very different things get filed under "impurities".
| Creatinine | DCD and DHT | |
|---|---|---|
| What it is | Your creatine, folded into a ring | Leftovers from the synthesis reaction |
| Where it comes from | The product itself, over time | The raw material, at manufacture |
| When it appears | Grows continuously after production | Present on day one or not at all |
| Controlled by | Formulation, storage, shelf time | Raw-material specification and supplier |
| What it costs you | Dose — you get less creatine | Purity — a different question |
| Who publishes limits | Nobody in this category | Create: DCD ≤50 ppm, DHT ≤3 ppm |
Dicyandiamide and dihydrotriazine are manufacturing residues — a supplier question, fixed at the moment the powder is made, and covered in full in our piece on impurity limits. A brand can buy pharmaceutical-grade powder with tight DCD and DHT ceilings and still ship a gummy that has lost a quarter of its creatine to cyclization, because those are unrelated failure modes. Buying clean raw material does not protect the finished product from time.
And no brand in this category publishes a creatinine ceiling for its finished gummy. Not one. That is the actual gap.
What it means when a lab reports "elevated creatinine"
Across the three independent testing rounds we track, 16 of 28 product tests missed label claim. When a report pairs a low creatine figure with elevated creatinine, it is telling you something specific: this is not a company that skimped on the recipe. This is a product that was dosed and then converted, somewhere between the mixing tank and the analyser.
It is a chemical timestamp. Elevated creatinine with a low creatine number points at formulation and shelf time — the format doing what the format does. A low creatine number with no creatinine points somewhere else entirely: at a product that never contained the stated dose. In the SuppCo round, some products contained only trace creatine and others none detectable at all, which is a fraud problem rather than a chemistry problem.
This also explains a result people find contradictory. Create was flagged in the NOW Foods round alongside Beast Bites and Con-Cret, then measured 4.59 g against a 4.5 g label in the later ISO 17025 round and passed the Eurofins round after that. Degradation is lot-, age- and storage-dependent by its nature, so a single flagged result is a statement about one lot at one age, not a permanent property of a brand. It is also why a recent test is worth more than an old one, and why repeat testing is worth more than either.
Is creatinine bad for you?
As an ingredient you swallow, no — it is inert and excreted. The practical cost is that you are not getting your dose.
There is a separate, frequently confused point worth knowing. Taking creatine raises the creatinine level measured in your blood, because more creatine in muscle means more of the normal daily conversion. On a routine blood panel that can look like a marker of reduced kidney function in someone whose kidneys are fine. This is well documented and it is worth mentioning to a doctor before a blood test rather than after. We are not clinicians and this is not medical advice; if a result concerns you, that conversation belongs with your doctor, not a supplement site.
What you can actually do about it
- Treat the expiry date as real. For powder it is conservative. For a gummy it is a genuine cutoff, because the reaction has been running since the day it was made. More on shelf life.
- Do not bulk-stockpile gummies. Buying six months at once means the last months are meaningfully weaker than the first. Powder stockpiles fine; gummies do not. This is also why multi-month bundles are a worse deal than they look.
- Store them cool and sealed. Activation energy around 20 kcal/mol means the rate is meaningfully temperature-sensitive. A cupboard beats a car, a windowsill or a gym bag — by a lot, not a little.
- Do not pre-mix powder and leave it. Same day is fine. Three days in an acidic flavoured drink is a real loss.
- Weight recent independent testing heavily. Certification tells you what is not in a product; only an assay tells you how much creatine survived. A result from this year beats a result from three years ago, because the whole variable is time.
- If dose certainty is what you care about most, buy powder. It is the honest conclusion of this chemistry, and it is cheaper. The case for gummies is adherence — the dose you actually take beats the better one you skip — and that is a real argument. Just make it knowingly. The full comparison.
Where this leaves our pick: no gummy escapes this chemistry, so the question is which one has been measured recently. Create is the only gummy in our set with a current independent ISO 17025 assay that came back above its own label — 4.59 g against 4.5 g — and the only one publishing a stability-testing commitment behind its expiry date, which is the brand's own statement rather than an independent finding. That is a narrow claim and we would rather state it narrowly than oversell it.
Opens the official Create site · 20% comes off at checkout · we may earn a commission · prices checked Sep 14, 2026
Sources
- Jäger R. et al., Analysis of the efficacy, safety, and regulatory status of novel forms of creatine, Amino Acids (2011) — powder stability to three years, solution degradation by pH, the pH 2.5 protonation floor. Springer
- Uzzan M., Nechrebeki J., Zhou P., Labuza T.P., Effect of water activity and temperature on the stability of creatine during storage, Drug Dev Ind Pharm 35(8):1003–8 (2009) — first-order kinetics, absence of a dilution effect below aw 0.7, activation energies. PubMed
- Saiki P.Y., Sales G.M., de Oliveira A.N., Catharino R.R., Multi-analytical characterization of creatine degradation for dietary supplement safety assessment, Food Research International 221 (2025) — temperature as the dominant factor; degradation products at alkaline but not acidic pH. PubMed
- Kreider R.B. et al., ISSN position stand: safety and efficacy of creatine supplementation, JISSN (2017) — the pH and temperature rule; the 1–2% daily physiological conversion. JISSN
- Pectin gummy manufacturing parameters — activation at 85–95 °C, depositing at 75–80 °C, target pH 2.8–3.5. Pacific Pectin manufacturing guide
Sources checked 14 September 2026. Lab-round results as reported by the testing organisations; we have not commissioned testing of our own. How we verify.
Questions
What is creatinine and how is it different from creatine?
Creatinine is what creatine becomes when the molecule folds in on itself and expels a water molecule, a reaction called intramolecular cyclization. The ring that forms has no biological activity as a supplement — your kidneys filter it out. It is not a contaminant added to the product; it is the creatine you paid for, in a form that no longer does anything.
Why do creatine gummies degrade faster than powder?
The reaction needs water, heat and time, and is accelerated by acid. Dry powder supplies none of them, and published data shows no measurable degradation after three years at room temperature or 40 °C. A pectin gummy supplies all of them: it is cooked at 85–95 °C, must be acidified to pH 2.8–3.5 in order to gel, contains water, and then sits on a shelf for months.
How fast does creatine turn into creatinine in water?
Published measurements at 25 °C over three days show about 4% lost at pH 5.5, 12% at pH 4.5 and 21% at pH 3.5. The rate tracks pH rather than concentration, so mixing it more dilute does not protect it. Over a single afternoon in a shaker the loss is negligible.
Does creatine turn into creatinine in your stomach?
Essentially no, and the reason is counterintuitive. Below about pH 2.5 the relevant amide group becomes protonated and the cyclization is blocked entirely. Stomach acid is well below that threshold, so conversion during gut transit is minimal regardless of how long it takes. The claim that creatine is destroyed in the stomach was used to market alternative creatine forms; the chemistry does not support it.
Doesn't a gummy's low moisture protect the creatine?
Less than you would expect. In most food systems, reaction rates fall off sharply below a water activity of about 0.7 — the dilution effect that shelf-stable food design relies on. A 2009 study testing creatine across water activities from 0.31 to 0.983 found it did not show that effect: half-life fell on a straight line against water activity with no protective cliff. A gummy is slower than a glass of water, but it is not the safe harbour the texture suggests.
Is creatinine in a supplement harmful?
As an ingredient, no — it is inert and excreted. The cost is that you are under-dosed. Separately, taking creatine raises the creatinine measured in a blood test, because more muscle creatine means more of the normal daily conversion, and that can resemble a kidney marker in someone with healthy kidneys. Worth mentioning to your doctor before a blood panel. We are not clinicians and this is not medical advice.
Is creatinine the same as the DCD and DHT impurities?
No, and conflating them is the most common error in this category. Dicyandiamide and dihydrotriazine are residues from manufacturing the raw creatine — present on day one or not at all, and controlled by the supplier specification. Creatinine accumulates after manufacture and is controlled by formulation and shelf time. A brand can buy powder with tight DCD and DHT limits and still ship a gummy that has lost a quarter of its creatine.
What does it mean if a lab reports elevated creatinine in a product?
That the product was probably dosed correctly and then degraded. A low creatine figure paired with elevated creatinine points at formulation and shelf time; a low creatine figure with no creatinine points at a product that never contained the stated dose. Because degradation depends on lot, age and storage, a single flagged result describes one lot at one age rather than a permanent property of a brand.