Evidence explainerCreatine monohydrate

Creatine Loading Phase: Do You Need It, and Why Did the Scale Just Jump?

Twenty grams a day for a week, or a few grams from day one? NIH describes both. Here is what each does, why your weight moves, and the lab-test quirk to know about.

By Kymata Health editorial teamPublished October 9, 2026Last reviewed October 9, 2026

Medical review pending. Written by our editorial team from the studies cited below; a credentialed clinician has not reviewed it yet. Educational only, not medical advice.

Key takeaways

  • NIH describes two approaches used in studies: a 5 to 7 day load at 20 g/day followed by 3 to 5 g/day, or about 3 to 6 g/day with no load for 3 to 4 weeks; both produced ergogenic effects [1].
  • A 2024 trial included monohydrate groups with and without a 5-day load; both gained strength and muscle versus placebo [2].
  • A 1 to 2 kg weight gain in the first month is common and mostly water held in muscle [1].
  • Creatine can raise serum creatinine, a standard kidney lab, without a significant change in filtration rate in trials, so mention it before blood work [3].

Safety at a glance

From our Creatine monohydrate monograph. Published interactions and cautions only, each with its source.

Who should be careful

  • Medicines. Our sources (NIH ODS) document no drug interactions for creatine. That means none are published in these sources, not that creatine is safe with every medicine.[1]
  • Kidney. A 2025 meta-analysis found a small rise in serum creatinine (significant at follow-ups under 1 week and over 12 weeks, not at 1–12 weeks) with no significant change in glomerular filtration rate. Because creatinine is a routine kidney test, this can complicate lab results. Trials mostly enrolled healthy people, so anyone with kidney disease or reduced kidney function should discuss creatine with their clinician first.[12]
  • Pregnancy and breastfeeding. Insufficient human safety data in our sources.[1]
  • Liver. No liver-specific human safety data in our sources.[1]

Full Creatine monohydrate safety section

The evidence, graded

Pulled from our monograph evidence tables. Grades follow our evidence-grading policy.

  • Grade AImprovedMuscle strength with resistance trainingCreatine monohydrate · Meta-analysis · n=509 · 2024 · PMID 39519498Versus placebo, upper-body strength +4.43 kg and lower-body strength +11.35 kg. Gains were significant in men; women showed no significant gains, but only 2 trials (40 women) were female-only.
  • Grade DImprovedStrength and muscle size with creatine HClCreatine monohydrate · RCT · n=40 · 2024 · PMID 39545789Both HCl and monohydrate increased strength, muscle cross-sectional area and skeletal muscle mass more than placebo. Creatine HCl showed no benefit over monohydrate.

Two ways to start, both used in research

The NIH Office of Dietary Supplements describes a typical research approach as a loading phase of 5 to 7 days at 20 g/day of creatine monohydrate in four 5 g portions, followed by 3 to 5 g/day [1]. Some studies scale the load to body weight, for example 0.3 g/kg [1].

NIH also describes a no-load approach: single amounts of about 3 to 6 g/day (0.03 to 0.1 g/kg) for 3 to 4 weeks, which also produced ergogenic effects [1]. In plain terms, loading gets you to the same place, sooner.

A 2024 trial in 40 young adults is a useful snapshot: one monohydrate group loaded at 0.3 g/kg/day for five days, another took 0.03 g/kg/day from the start, and both improved strength, muscle cross-sectional area and muscle mass more than placebo over eight weeks [2]. The abstract does not report a head-to-head difference between the two monohydrate groups, and each group had only 10 people [2].

Why the scale jumps (and why it is not fat)

NIH notes that the one consistent side effect across creatine studies is weight gain, because creatine increases water retention and possibly muscle protein synthesis [1]. In strength-training studies, the gain is often 1 to 2 kg in the first month [1].

That water is held inside muscle cells. It is also part of why trials report lean-mass gains: on our creatine monograph we note that some of the measured lean mass likely reflects water. If you compete in a weight class or an endurance sport, NIH flags that the extra weight could be a drawback [1].

The blood-test quirk

Creatinine is a breakdown product of creatine and a routine kidney marker. A 2025 meta-analysis found creatine produced a small but statistically significant rise in serum creatinine, with no significant change in glomerular filtration rate [3]. The authors attribute the rise to creatine turnover rather than kidney harm [3].

The trials mostly enrolled healthy people. Tell your clinician you use creatine before blood work, and if you have kidney disease or reduced kidney function, discuss it with them before starting [3].

Do you need a fancier form to skip the bloat?

Creatine HCl is often marketed as gentler. In the 2024 trial above, HCl showed no benefit over monohydrate for strength or muscle [2]. A review of newer creatine forms found little to no evidence that any of them is more effective or safer than monohydrate [4], and we found no published human comparison of stomach comfort between HCl and monohydrate. Monohydrate remains the form used in nearly all of the research.

Quick answers

Will I lose the gains if I skip loading?

NIH describes 3 to 6 g/day without loading for 3 to 4 weeks as producing ergogenic effects [1]. Loading mainly changes how fast you get there.

How long does the water weight last?

Studies report the 1 to 2 kg rise over the first month of strength training with creatine [1]. We found no trial data on how quickly it goes away after stopping.

Keep reading

Full monographs

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References

  1. [1]Dietary Supplements for Exercise and Athletic Performance: Fact Sheet for Health Professionals (creatine section). NIH Office of Dietary Supplements, 2024.
  2. [2]Supplementing With Which Form of Creatine (Hydrochloride or Monohydrate) Alongside Resistance Training Can Have More Impacts on Anabolic/Catabolic Hormones, Strength and Body Composition?. Physiol Res, 2024. PMID 39545789
  3. [3]Effect of creatine supplementation on kidney function: a systematic review and meta-analysis. BMC Nephrol, 2025. PMID 41199218
  4. [4]Analysis of the efficacy, safety, and regulatory status of novel forms of creatine. Amino Acids, 2011. PMID 21424716

Creatine monohydrate and other dietary supplements are not intended to diagnose, treat, cure or prevent any disease, and these statements have not been evaluated by the FDA. Talk to your clinician or pharmacist before starting a supplement, especially if you take prescription medicines. This page has no product or affiliate links.

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