"Creatine before and after" is searched about 9,000 times a month, and the results are almost entirely photographs. This page answers the same question from the trial registry instead, and the census turns out to be the story: the before-and-after has been promised in 41 registered trials and published in the registry once. It reports what was measured and what was posted, and contains no usage guidance, per our editorial standards.
The census
ClinicalTrials.gov is where trials record what they intend to measure before they measure it, and where results are posted afterwards. Queried on 2026-09-18:
| Query | Registrations | With posted results |
|---|---|---|
| Creatine as a registered intervention | 193 | 17 |
| …listing a muscle mass outcome | 41 | 0 |
| …listing a body composition outcome | 32 | 0 |
| …listing a lean body mass outcome | 24 | 0 |
Forty-one trials set out to measure whether creatine changes muscle mass. Not one of them has posted a result.
This is not the same as saying the research does not exist. The journal literature on creatine and lean mass is large, and this site reads it elsewhere. It is saying something narrower and, for a reader trying to check a claim, more useful: the part of the record that can be compared against a pre-declared plan is empty for this outcome. A published paper reports what the authors chose to report; a registry entry with posted results reports what they said in advance they would measure. For the muscle-size question, the second record is blank.
What the 17 posted trials are actually about
The seventeen that did post results are worth listing by subject, because it explains the gap:
- Depression and psychiatric endpoints — seven trials, including several in adolescent females and in people using methamphetamine.
- Neurological disease — Huntington's disease, a 1,741-participant Parkinson's trial, amyotrophic lateral sclerosis, Angelman syndrome.
- Other clinical — peripheral artery disease, electroconvulsive therapy augmentation, middle-aged women's verbal learning.
- Metabolic — one trial in vegetarians, with a plasma beta-alanine primary outcome.
- Muscle — one.
Sixteen of the seventeen are not about appearance or athletic performance at all. The registry's creatine evidence is largely a psychiatric and neurological literature, which is a genuinely surprising shape for a supplement sold almost entirely to lifters.
The one that posted
NCT02188849 — Effects of Creatine Supplementation on Muscle Mass and Function Among Older Women Subjected to Resistance Training. Fifty community-living older women, randomised double-blind to 5 g of creatine a day or an identical placebo, with a supervised progressive resistance-training programme of three one-hour sessions a week for twelve weeks.
Posted results at twelve weeks:
| Outcome | Creatine | Placebo |
|---|---|---|
| Rectus femoris cross-sectional height | 17.5 cm (SD 2.0) | 17.6 cm (SD 2.8) |
| Quadriceps isometric strength | 278.6 N (SD 53.9) | 225.3 N (SD 50.6) |
| Twelve-minute walk | 1,091 m (SD 101) | 1,088 m (SD 108) |
| Serum creatinine | 0.80 mg/dl (SD 0.12) | 0.75 mg/dl (SD 0.13) |
Three things are worth reading carefully.
The muscle-size measure did not separate. 17.5 against 17.6 centimetres, with standard deviations of 2.0 and 2.8, is not a difference. This is the direct ultrasound thickness of a quadriceps muscle — the outcome hardest to confuse with water or fat — and after twelve weeks of supervised training it looked the same in both arms.
The strength measure did. 279 newtons against 225 is a substantial gap. Whatever produced it, it was not extra muscle at the site that was imaged.
The walking test did not. Force in an isolated isometric test moved; a functional task did not. That pattern — a measurable change in a laboratory outcome without a matching change in what a person can do — is the same one this site has recorded across the growth-hormone axis and, in a different drug class entirely, in the peptides versus steroids comparison. It is not specific to creatine, and it is the reason a single number from a trial should always be read with its companions.
The serum creatinine difference is expected and is not a kidney finding; the reason is set out on creatine and kidneys and on what creatine is in bloodwork.
Why the photographs cannot answer this
There is a specific study, not merely a general caution.
A 2003 trial measured total body water with deuterium oxide and extracellular water with sodium bromide dilution, in 16 men and 16 women over 28 days, with muscle biopsies. Total body water rose in the creatine group, and the distribution between compartments did not change. The detail that matters here is elsewhere in the same paper: the placebo group's total body water also rose significantly.
A person taking their own before-and-after photograph has no placebo group. They cannot separate the supplement from the training, the food, the hydration, the time of day, the lighting or the four weeks of ordinary variation that the placebo arm just demonstrated. The measurement problem is not that the photographs are dishonest; it is that there is nothing to compare them against.
The scale has the same problem for a different reason, which is that the early change is largely water — the subject of does creatine make you gain weight and creatine bloating, both of which carry the compartment measurements.
What a reader can take from this
- The registered evidence for a visible before-and-after is one trial, in older women, with the size outcome flat.
- Forty-one further trials promised that outcome and have posted nothing.
- The strength result in the one posted trial was real and large, and did not come with a change in measured muscle thickness.
- Anything presented as a typical result over four, eight or twelve weeks is drawn from the journal literature, not from the registry, and should name its study.
That is a thinner answer than the search deserves, and stating it plainly is the honest version of this page. When one of those 41 trials posts, it will be a better one.
What would change this page
Any of the 41 registered muscle-mass trials posting results. A second registered trial with imaging at multiple timepoints. Or a published trial reporting the distribution of individual responses rather than group means, which is what a reader asking about before-and-after is really asking for and which almost nothing reports.
Key figures
- 193 registered creatine trials; 17 with posted results.
- 41 promising a muscle-mass outcome; 0 with posted results.
- 17.5 cm vs 17.6 cm — muscle thickness at twelve weeks, creatine against placebo.
- 279 N vs 225 N — isometric strength in the same trial.
- 1,091 m vs 1,088 m — twelve-minute walk in the same trial.
This page reports registry records and posted trial results. It contains no recommendation, and decisions about supplementation belong with a clinician.
Sources
- ClinicalTrials.gov API v2 — census of studies with creatine as a registered intervention, filtered by posted results and by outcome measure, run 2026-09-18 — clinicaltrials.gov
- ClinicalTrials.gov. Effects of Creatine Supplementation on Muscle Mass and Function Among Older Women Subjected to Resistance Training, NCT02188849 — protocol and posted results section read in full 2026-09-18 — clinicaltrials.gov/study/NCT02188849
- Powers ME, Arnold BL, Weltman AL, et al. Creatine Supplementation Increases Total Body Water Without Altering Fluid Distribution. J Athl Train 2003;38(1):44–50 — PMID 12937471
- Kreider RB, Gonzalez DE, Hines K, et al. Safety of creatine supplementation. J Int Soc Sports Nutr 2025;22(sup1):2488937 — PMID 40198156 · doi:10.1080/15502783.2025.2488937
All sources retrieved 2026-09-18. Registry counts are as of that date and will move as results are posted.