What Is Creatine? The Compound, Phosphocreatine and the 3g Rule
What is creatine?
Not a stimulant, not a hormone, not a steroid — and not something foreign you're introducing. Your body makes it and your muscles are storing it right now. Here's what creatine actually is, how the phosphocreatine system works, and the single thing it's legally allowed to be sold on in the UK.
What is creatine — explainer summary
Creatine is a naturally occurring compound formed from three amino acids: glycine, arginine and methionine. The human body synthesises it in the liver, kidneys and pancreas, and the great majority of the body's creatine is then stored in skeletal muscle. It is not a stimulant, a hormone or a steroid. Most of the creatine held in muscle is stored as phosphocreatine, which acts as a rapid phosphate reserve. When a muscle contracts hard it spends adenosine triphosphate, or ATP, the cell's immediate energy currency, and ATP stores are very small. Phosphocreatine donates a phosphate group to regenerate ATP quickly. That system is fast but short-lived, which is why creatine is associated with brief bursts of high-intensity effort rather than endurance activity. This describes normal physiology and is not a health claim. Creatine is also obtained from the diet, principally from meat and fish, at an amount typically estimated around 1 to 2 grams per day on an omnivorous diet. It varies with intake and with cooking, since creatine degrades under prolonged heat. Plant foods contain negligible creatine, so vegetarians and vegans generally obtain very little from food. Creatine monohydrate is the form referenced by the single authorised Great Britain and European Union health claim and by the great majority of the research base, and it is generally the cheapest per gram of creatine delivered. Alternative forms including creatine hydrochloride, ethyl ester, buffered creatine and liquid creatine are marketed as improvements, but no authorised claim distinguishes one creatine form from another. Creatinine is the inactive breakdown product of creatine. The body produces it continuously and clears it through the kidneys, which is why blood creatinine is used clinically as a marker of kidney function. Creatine can also convert to creatinine outside the body in the presence of moisture, heat and acidity, which is why the creatine content of a finished product matters more than that of the raw material, particularly in formats containing moisture. The single authorised health claim states that creatine increases physical performance in successive bursts of short-term, high-intensity exercise. Its conditions of use permit it only for a food providing a daily intake of 3 grams of creatine, require consumers to be informed that the beneficial effect is obtained with that daily intake, and identify the target population as adults performing high-intensity exercise. No claims regarding muscle growth, strength, recovery, body composition or cognition are authorised in the United Kingdom. A loading phase is not required by the authorised claim. Creatine supplements are not intended for children.
Something your body already makes.
Creatine is built from three amino acids — glycine, arginine and methionine — and your body synthesises it in the liver, kidneys and pancreas. From there the great majority of it goes to skeletal muscle, which is where nearly all of your body's creatine sits.
That's worth stating plainly because creatine attracts a lot of confusion. It isn't a stimulant. It isn't a hormone. It isn't a steroid. And supplementing isn't introducing a foreign substance — it's adding to a pool you already maintain and already top up from food.
The phosphocreatine system.
Muscle contraction is paid for in ATP — adenosine triphosphate, the cell's immediate energy currency. The catch is that cells hold very little of it. Enough for a few seconds of hard effort, not more.
Most creatine in muscle is held as phosphocreatine — creatine carrying a phosphate group, sitting ready.
A hard contraction burns through the small ATP store quickly. Something has to regenerate it, immediately.
Phosphocreatine hands over its phosphate group to rebuild ATP — the fastest system the cell has.
That system is fast but short-lived, which is the whole reason creatine is associated with brief, repeated bursts of maximal effort rather than with endurance. It's also why the authorised claim is worded the way it is — "successive bursts of short-term, high-intensity exercise" describes exactly the window this system covers.
Everything above describes normal physiology — how a system in your body works — rather than making a claim about what a supplement will do for you. That distinction matters legally, and we'll be explicit about it below.
You already eat some.
Creatine comes principally from meat and fish. On an omnivorous diet, intake is typically estimated at around 1 to 2 grams per day — though it varies a lot with how much meat and fish someone actually eats, and with cooking, since creatine degrades under prolonged heat.
Plant foods contain negligible creatine. So vegetarians and vegans generally get very little from the diet, and that's a straightforward compositional fact rather than a claim about anyone's requirements.
Set that dietary figure against the number that matters commercially: the authorised health claim is conditioned on a daily intake of 3 grams. Typical dietary intake sits below it. That gap is the practical reason creatine supplements exist — and the reason a supplement below 3g a day can't lawfully carry the claim at all.
Monohydrate is the reference.
Creatine is sold in several forms, most of them positioned as improvements on the original. Here's the honest position:
| Form | Position |
|---|---|
| Creatine monohydrate | The form the authorised claim and most of the research base refer to. Generally the cheapest per gram delivered |
| Creatine hydrochloride (HCL) | Marketed on solubility and smaller doses. No authorised claim distinguishes it |
| Buffered creatine | Marketed on pH stability. No authorised claim distinguishes it |
| Creatine ethyl ester | Marketed on absorption. No authorised claim distinguishes it |
| Liquid creatine | Creatine in solution raises the same degradation question as any moist format |
No authorised UK or EU claim distinguishes one creatine form from another. So when a costlier form is sold on being more effective, the fair question is what authorises that statement — and generally nothing does. Our creatine buying guide goes through this in more detail.
Creatine and creatinine are not the same thing.
One letter apart, and they get mixed up constantly. Creatinine is the inactive breakdown product of creatine. Your body produces it continuously as creatine and phosphocreatine break down, and the kidneys clear it — which is why blood creatinine is used clinically as a marker of kidney function.
The part that matters when you're buying: creatine can also convert to creatinine outside the body, in the presence of moisture, heat and acidity. Dry powder in a sealed tub isn't exposed to those conditions. A format containing moisture is.
Which is why, for any moist format, the meaningful measurement is creatine content in the finished product rather than in the raw material that went into it — two different laboratory tests. That's a fair question to put to any brand selling creatine in a gummy, including us. We cover it properly in gummies vs powder.
What creatine is allowed to be sold on.
Creatine has exactly one authorised health claim in Great Britain and the EU. Everything else you'll see attached to it in marketing is not authorised:
| Claim | Status in Great Britain |
|---|---|
| Increases physical performance in successive bursts of short-term, high-intensity exercise | Authorised. Only for food providing a daily intake of 3g creatine; consumers informed the effect is obtained with 3g/day; target population adults performing high-intensity exercise |
| Builds muscle | Not authorised |
| Increases strength | Not authorised |
| Speeds recovery | Not authorised |
| Improves body composition | Not authorised |
| Cognitive or brain benefits | Not authorised |
| One form outperforms another | Not authorised — no claim distinguishes forms |
Note the gap between the mechanism and the claim. Describing how phosphocreatine regenerates ATP is physiology, and we can explain it. Telling you a product will therefore build your muscles is a claim, and it isn't authorised. Plenty of brands slide from the first into the second in a single sentence — worth watching for, because it tells you how carefully the rest of the label was written.
Ready to choose one?
Our buying guide applies the 3g threshold and the monohydrate test to real products, with an honest comparison of powder and gummies.
Common questions.
Keep going.
- BuyingBest creatine UK — the 3g rule, monohydrate and format
- BuyingBest creatine gummies UK — the 3g threshold applied
- CompareCreatine gummies vs powder — cost, sugar, dosing, stability
- ShopCreatine gummies — the UK range
- QualityQuality, testing & sourcing — UK manufacture and batch CoAs
- ResearchResearch references — every study we cite
- EditorialEditorial standards — how we research and review
Last reviewed 17 August 2026 by the Vitality Supplements Editorial Team, written to our published editorial standards and quality & testing policy. We are a UK supplement manufacturer and we sell creatine, in gummy format only, which we disclose openly. One editorial decision worth naming: this page explains the phosphocreatine mechanism because that is physiology and can be described, but it does not slide from that explanation into telling you what a supplement will do for you — which would be an unauthorised claim. The single authorised creatine claim is quoted with its conditions of use in full, and the claims that are commonly made and are not authorised are listed explicitly rather than repeated.
Food supplements should not be used as a substitute for a varied, balanced diet and a healthy lifestyle. Do not exceed the stated recommended daily dose. The authorised GB and EU health claim for creatine — that creatine increases physical performance in successive bursts of short-term, high-intensity exercise — may be used only for food which provides a daily intake of 3g of creatine; the beneficial effect is obtained with a daily intake of 3g of creatine; the target population is adults performing high-intensity exercise. No other health claims are authorised for creatine in the United Kingdom, and no claims regarding muscle growth, strength, recovery, body composition or cognition are made here. Not suitable for children. If you are pregnant, breastfeeding, taking medication, or have a kidney condition or any other medical condition, consult a healthcare professional before use. This page is general information, not medical advice, and is not intended to diagnose, treat or prevent any condition. Every Vitality batch is independently tested. UK manufactured. Free UK delivery. 60-day satisfaction guarantee on first purchase. See our full disclaimer · Privacy · Terms · info@vitality-supplements.co.uk