Creatine
Best-in-class: Creatine
The single most-studied sports supplement. Rapidly regenerates ATP for high-intensity work by expanding phosphocreatine stores. Thorne's is NSF Certified for Sport (clean for tested athletes).
Creatine quick facts
| Suggested dose | 3–5 g daily, every day, timing-independent. No loading required. |
| How often | Daily |
| Who it's for | Every strength/power athlete, and increasingly a general-health/cognition staple across ages. |
| Best-in-class brand | Creatine |
The most evidenced supplement in sport, and unusually one where the cheap version is the correct version — monohydrate is what essentially every trial used, and the exotic forms exist for margin, not results. Loading is optional; 3–5 g daily reaches the same saturation in about three to four weeks. The weight gain in the first fortnight is intramuscular water, not fat. It does not damage kidneys in healthy people, though it does raise serum creatinine — which will look alarming on a blood test if nobody warned you first.
How Creatine actually works
Creatine works by buffering, not by adding energy. Muscle stores it as phosphocreatine, and creatine kinase transfers that phosphate to spent ADP to regenerate ATP almost instantly — faster than glycolysis or mitochondria can respond. That matters only in the first seconds of maximal effort, which is why the benefit is concentrated in repeated hard sets rather than endurance. Loading raises muscle stores by roughly 20–40% in most people. The same phosphocreatine system operates in the brain, which is the mechanistic basis for the cognitive work in sleep-deprived and vegetarian populations.
Where to get Creatine
Buy Creatine at Thorne →The evidence for Creatine
Graded by what exists behind each claim.
✅ Clinically validated
- Consistently increases strength, power and lean mass when combined with training (hundreds of RCTs; meta-analyses robust).
- Improves high-intensity/repeated-sprint performance.
- Emerging RCT evidence for cognition/memory benefits, especially under sleep deprivation or in older adults.
📊 Correlative data
- Higher muscle creatine stores track with better anaerobic performance; vegetarians (lower baseline) tend to respond most.
🧪 Theoretical / extrapolated benefits
- Proposed neuroprotective and mood roles via brain bioenergetics are promising but earlier-stage than the muscle data.
How to read these tiers: they say how much human evidence exists, not how well something works — and ✗ flags harm, never a disappointing trial. How the evidence tiers work →
What Creatine actually does
Creatine is a phosphate buffer, and the enzyme that makes it useful is reversible. Creatine kinase transfers a phosphoryl group between ATP and creatine in both directions. During a maximal effort, phosphocreatine donates its phosphate to ADP faster than any other system can, holding ATP concentration nearly constant while it is consumed at an enormous rate. The store is small — enough for about 10 seconds of maximal work — and the whole ergogenic case is about making that store slightly larger and refilling it slightly faster.
Getting it into muscle is an active, saturable, sodium-dependent transport step. The creatine transporter SLC6A8 moves creatine against a concentration gradient of roughly 200-fold, using the sodium and chloride electrochemical gradient. It is downregulated by high intracellular creatine, which is the mechanical reason muscle stores have a ceiling near 150 to 160 mmol per kg dry mass and why loading beyond it does nothing Hultman 1985.
The body already makes about half of what it uses, and it does so in two organs. Arginine:glycine amidinotransferase in the kidney makes guanidinoacetate; guanidinoacetate N-methyltransferase in the liver methylates it using S-adenosylmethionine. That second step is one of the largest consumers of methyl groups in the body, which is why creatine supplementation lowers homocysteine in some studies and why it interacts with the methylation pages in this catalog.
The exit route is non-enzymatic and constant, and it is the source of the confusion this page is about. Creatine and phosphocreatine cyclize spontaneously to creatinine at a fixed fractional rate of roughly 1.7 percent of the pool per day. Creatinine is then renally cleared. A larger creatine pool therefore produces more creatinine, every day, by simple chemistry — with no change in the glomerulus at all.
And there is a second tissue with a different constraint. Brain creatine turns over more slowly and the blood-brain barrier expresses relatively little SLC6A8, so raising brain creatine takes longer and higher doses than raising muscle creatine. That is why the cognitive literature runs on different timescales from the performance literature Smith 2025.
Cell, rodent, human — and where it stops
This is one of the few pages in this cohort where the outcome evidence is stronger than the marker evidence. The surrogate problem here is a different one: a number that rises and means nothing.
In humans, the muscle loading study is the foundation. Twenty grams a day for six days raises muscle total creatine by roughly 20 percent, 3 g a day reaches the same ceiling in about 28 days, and people who start with low muscle creatine gain the most Hultman 1985. That is a direct tissue measurement rather than a plasma marker, which is unusual and is why this literature is trusted.
The performance outcome followed the marker, which almost never happens. The position stand summarizes hundreds of trials: consistent improvement in high-intensity repeated-effort work, in strength gains over a training block, and in lean mass, with the effect concentrated in short maximal efforts and absent in endurance events Kreider 2017.
Where the transfer breaks is the non-responder, and the reason is baseline. Somewhere between a fifth and a third of people gain little muscle creatine because they started near the ceiling — typically meat eaters with high habitual intake. Vegetarians show the largest increases. A trial averaging responders and non-responders reports a smaller mean effect than either group experiences Kreider 2022.
In the brain the chain is much shorter and the newest work is honest about it. A pilot in Alzheimer's disease established feasibility and measured brain creatine directly by spectroscopy alongside cognition Smith 2025, and an 8-week comparison of two alternative forms measured brain creatine as well as cognitive outcomes Korovljev 2025. Measuring the tissue rather than assuming it is the right design and it is still at pilot scale.
And the marker that fails is serum creatinine. A rise of roughly 0.1 to 0.3 mg/dL on supplementation reflects a larger creatine pool, not renal injury, and the narrative review of the creatine-and-kidney literature concludes that decades of case reports have not produced evidence of harm in people with normal renal function Longobardi 2023. The number moved; the kidney did not.
Creatine — which form, and does it matter
Creatine monohydrate is the studied material and everything else is a solubility argument in search of an endpoint. The critical review of forms concludes that no alternative has demonstrated superiority over monohydrate for raising muscle creatine or for performance, and several are less stable Kreider 2022. That is an unusually firm conclusion for a supplement category.
The alternative forms fail for chemical reasons that are worth naming. Creatine ethyl ester is hydrolyzed rapidly at gastric pH to creatinine rather than to creatine, so a portion of the dose is degraded before absorption. Buffered forms rely on the premise that monohydrate is destroyed in the stomach, which it largely is not. Creatine hydrochloride is more soluble and there is no evidence that solubility was ever the limiting step. An analysis of alternative creatine products sold online found label claims frequently unsupported Escalante 2022, and a direct 8-week comparison of hydrochloride and ethyl ester measured brain creatine as an objective endpoint Korovljev 2025.
The pharmacokinetics explain both the loading protocol and the 3 gram maintenance dose. Oral creatine is absorbed nearly completely at doses up to about 5 g, with peak plasma concentration at roughly 1 to 2 hours and a plasma half-life of about 3 hours. There is no cytochrome metabolism and no meaningful first-pass step; plasma creatine is either taken up by SLC6A8 into muscle or lost to renal clearance. Because muscle uptake is slow relative to plasma clearance, a large single dose mostly ends up in urine, and splitting doses genuinely raises retention.
The clocks are 6 days, 28 days and 4 to 6 weeks. A 20 g loading phase saturates muscle in about 6 days; 3 g daily reaches the same place in about 4 weeks Hultman 1985. Washout after stopping takes 4 to 6 weeks, following the 1.7 percent daily conversion to creatinine. Nothing about creatine is fast except the loading protocol.
Two practical form notes. Micronized monohydrate is the same molecule with smaller particles and dissolves better, which is a palatability improvement rather than a pharmacological one. And insulin stimulates SLC6A8, which is why co-ingestion with carbohydrate modestly raises retention — the one delivery trick in this category with a mechanism behind it Kreider 2017.
What would have to be true, and how you would know it was not
1. Predict body mass rises 1 to 2 kg in the first week and that it is water. Creatine is osmotically active and drawn into muscle with water. Predict the gain during a loading phase is intracellular fluid, that it appears within days, and that lean tissue accrual over a training block is a separate and slower phenomenon Kreider 2017.
2. Predict serum creatinine rises and estimated GFR falls, and predict cystatin C does not. This is the most useful test on the page. Creatinine is generated from the enlarged creatine pool; cystatin C is a separate filtration marker with no creatine dependence. Predict a small rise in creatinine with an unchanged cystatin C with eGFR, which distinguishes a bigger pool from a worse kidney Longobardi 2023.
3. The prediction that cuts against the product. In a habitual meat eater whose muscle creatine is already near the ceiling, predict little or no performance change, because the transporter downregulates and the store cannot expand Hultman 1985. Predict the largest responses in vegetarians. A trial finding uniform response irrespective of baseline muscle creatine would falsify this account.
4. Predict nothing in an endurance event. The phosphocreatine system supplies seconds, not minutes. Predict no improvement in a 10 km time and a measurable improvement in repeated 6-second sprints or in the last repetitions of a set. The duration boundary is the falsifiable part of the claim.
5. Predict a form comparison finds no difference. Predict that hydrochloride, ethyl ester and buffered forms match monohydrate on muscle or brain creatine at equal molar dose, and cost more Kreider 2022 Korovljev 2025. A trial showing a genuine advantage for any of them would overturn the firmest conclusion on this page.
What nobody has tested yet
The brain dose-response is not established. Muscle saturation takes 3 g a day; brain creatine responds slowly, incompletely and at higher doses, and the pilot literature has not settled how much or for how long Smith 2025. Every cognitive claim rests on that unfilled gap.
Nobody has done a long-term trial in chronic kidney disease. The safety literature is reassuring in people with normal renal function and essentially silent in people without it, because those people were excluded from the trials Longobardi 2023. That is precisely the group most likely to be told their creatinine looks worse.
The hair loss question has never been retested. A single small trial in rugby players reported a rise in dihydrotestosterone with unchanged testosterone, and no subsequent study has measured either hormone as a primary endpoint or measured hair. Two decades of argument rest on one unreplicated result, and replicating it would cost very little.
And the non-responder has never been characterized prospectively. Baseline muscle creatine predicts response Hultman 1985 and no accessible test estimates it. A validated blood or dietary proxy for muscle creatine saturation would let people know before spending a month finding out.
Creatine — its own safety story, not its category's
The best-documented adverse effect is a laboratory result that is not an adverse effect. A rise in serum creatinine on supplementation reflects the enlarged pool being converted at its usual fractional rate. Read as renal impairment it has led to unnecessary investigation and to people stopping training programs; the review of that literature finds no evidence of creatine-induced kidney failure in people with normal function Longobardi 2023. Tell whoever orders the test.
Real, common and minor. Gastrointestinal discomfort and diarrhea at single doses above about 10 g, resolved by splitting the dose. Weight gain from intracellular water, which matters in weight-class sports and in any sport where mass is a cost. Muscle cramping has been repeatedly alleged and repeatedly not found in controlled trials Kreider 2017.
Purity is a genuine risk in this category and it is a manufacturing one. Creatine is synthesized industrially from sarcosine and cyanamide, and poorly controlled production leaves dicyandiamide, dihydrotriazine and creatinine as contaminants. Product analyses have found label claims unsupported in alternative forms Escalante 2022, which makes third-party testing a more substantive recommendation here than it is for most supplements.
Who should have a conversation first. Anyone with existing kidney disease, not because harm is established but because it has never been studied and because the monitoring test becomes harder to interpret. Anyone on nephrotoxic medication, for the same monitoring reason. And anyone with a rare creatine transporter or synthesis disorder, where dosing is a clinical matter.
What this page will not do is pretend this is a risky product. Creatine monohydrate has the largest safety database of anything in this catalog, including multi-year use in adolescents and in clinical populations Kreider 2017. The honest caution is about a number on a report, not about the molecule. Nothing here is medical advice or diagnosis, and these statements have not been evaluated by the Food and Drug Administration.
Sources read for this page
- Kreider RB. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. J Int Soc Sports Nutr 2017 · PMID 28615996
- Hultman E. Muscle creatine loading in men. J Appl Physiol (1985) 1996 · PMID 8828669
- Kreider RB. Bioavailability, Efficacy, Safety, and Regulatory Status of Creatine and Related Compounds: A Critical Review. Nutrients 2022 · PMID 35268011
- Escalante G. Analysis of the efficacy, safety, and cost of alternative forms of creatine available for purchase on Amazon.com: are label claims supported by science?. Heliyon 2022 · PMID 36544833
- Longobardi I. Is It Time for a Requiem for Creatine Supplementation-Induced Kidney Failure? A Narrative Review. Nutrients 2023 · PMID 36986197
- Smith AN. Creatine monohydrate pilot in Alzheimer's: Feasibility, brain creatine, and cognition. Alzheimers Dement (N Y) 2025 · PMID 40395689
- Korovljev D. The Effects of 8-Week Creatine Hydrochloride and Creatine Ethyl Ester Supplementation on Cognition, Clinical Outcomes, and Brain Creatine Levels in Perimenopausal and Menopausal Women (CONCRET-MENOPA): A Randomized Controlled Trial. J Am Nutr Assoc 2025 · PMID 40854087
How you would know if it worked
These are the markers that recommend this product on their own pages, so they are the ones that should move if it is doing what it is sold for.
- Comprehensive Metabolic Panel (CMP) — (2) A 'high' creatinine in a muscular person on creatine is frequently benign — Cystatin C is the accurate kidney measure because it's unaffected by muscle mass Retest: Every 3–6 months on any oral compound; annually otherwise.
- Cystatin C with eGFR — High protein and creatine raise creatinine without harming kidneys — cystatin C sees through that noise Retest: Annually, or to confirm any abnormal creatinine-based eGFR.
- Osteocalcin — Creatine has emerging bone-health data alongside resistance training Retest: Annually if monitoring bone health.
The cheapest panel carrying Comprehensive Metabolic Panel (CMP) and at least one other of these is Kidney Health — Read Properly, at $92 — the panel is named for a different question, and the marker is the same marker. That is the whole cost of finding out.
Draw before you start, not after. A result with nothing to compare it to answers nothing.
Creatine — safety & side effects
- Weight gain of 1–2 kg in the first weeks is water inside muscle, not fat, and it is expected. GI upset and cramping usually mean the dose is too high or too concentrated at once.
- It raises serum creatinine without harming the kidneys — creatinine is its breakdown product. This routinely causes an eGFR to look worse and triggers unnecessary investigation. Mention it before a kidney panel, or use cystatin C instead.
- In *existing* kidney disease the evidence is reassuring but limited; that is a conversation with your nephrologist rather than a flat contraindication.
- One of the most studied supplements in existence, with a good long-term safety record. Loading is optional.
Not medical advice. If you take prescription medication or have a diagnosed condition, check this against it with a pharmacist or doctor — pharmacists are underused and free.
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The full Supplement Vault — 371 products across 14 categories with clinical, correlative & theoretical evidence, plus my Thorne partner links — lives inside Skool alongside 278 peptides.
Join Skool — $10/mo →Bloodwork to run alongside Creatine
Baseline first, then again at 8–12 weeks.
| Marker | What it’s watching for |
|---|---|
| Comprehensive Metabolic Panel (CMP) | Creatine raises creatinine WITHOUT harming kidneys — expect it, don't panic |
| Cystatin C with eGFR | The kidney marker creatine doesn't distort. Use it to settle the question |
| Complete Blood Count (CBC) with Differential | General baseline before a long-term daily supplement |
The Athletic Performance & Recovery panel covers these in one order — 12 markers, $207.90 with the discount applied.
Check results you already have → · All 103 markers A–Z
Creatine — frequently asked questions
What is Creatine?
The single most-studied sports supplement. Rapidly regenerates ATP for high-intensity work by expanding phosphocreatine stores. Thorne's is NSF Certified for Sport (clean for tested athletes).
What is the suggested dose of Creatine?
3–5 g daily, every day, timing-independent. No loading required. This is a general reference for education only — statements have not been evaluated by the FDA and this is not medical advice.
What are the researched benefits of Creatine?
Consistently increases strength, power and lean mass when combined with training (hundreds of RCTs; meta-analyses robust).
Who is Creatine for?
Every strength/power athlete, and increasingly a general-health/cognition staple across ages.
Where can I buy Creatine?
Coach Cam sources Creatine from Thorne, with 10% off auto-applied at checkout — use the buy link on this page.
Creatine inside a finished plan
One arm of 6 Protocol Blueprints, free to read in full.
What Creatine is used for
Creatine appears under 8 goals in the goal router.
Related Performance supplements
Where this goes next
Creatine is lean-mass protection of this plan. The page above is the free breakdown of one compound; the plan it belongs to — the dosing, the order to correct things in, the week-by-week schedule and what to retest — is a lesson inside Skool.