How long does creatine take to work?
Your muscles are full in about 6 days if you load, and in about 4 weeks on 3 to 5 g a day. The extra rep or two on hard sets shows up once they’re full. Any new muscle comes over the months of training after that.
Most people expect to feel creatine within days, the way you feel a coffee. What they notice first is the scale, which jumps in the first week for anyone who loads, and plenty of people take that as proof it’s working. Others feel nothing by week two and quit, a couple of weeks before their muscles were even full.
What we’d do
Count from the day your stores are full, and give it until week eight before you judge it. Do one test, like push-ups or a dead hang, twice before your first scoop and once more at week eight. The dose tool gives you the full-by date and the prove it tool gives you the retest date.
Why there’s a wait
Creatine works as a small reserve of fuel in your muscles. In the first seconds of a hard effort, your muscles burn through their energy molecule (ATP) and rebuild it from phosphocreatine, which is creatine with a phosphate attached. More creatine stored means a little more of that fast fuel for the last reps of a set.
It’s like a slightly bigger reserve tank on a car. The engine is the same, with a little more fuel for the last stretch before you have to stop. That’s also why it can’t help until the tank is full. The International Society of Sports Nutrition says the slow 3 g a day path may have less effect on training until stores are fully saturated.
The tank fills on a schedule. In the 1996 trial behind both paths, 20 g a day raised muscle creatine about 20% in 6 days, and 3 g a day reached the same 20% by day 28. Start on Monday, November 16 and you’re full by Saturday, November 21 if you load, or Sunday, December 13 on 3 to 5 g a day.
5 g a day may get you there a few days sooner than 3 g, but no trial has timed it, so we use day 28 for the whole range.
What happens when
| When | What happens |
|---|---|
| Week one | The scale goes up, mostly water. In a 2003 trial of 32 lifters who loaded, body water rose 1.37 L in the first week |
| Day 6 if you load, about day 28 if you don’t | Your muscles are full |
| Once you’re full | An extra rep or two on hard sets. Across 22 lifting studies, reps at the same weight rose 26% with creatine and 12% with training alone |
| The months after | More strength and muscle from all those extra reps. Across 35 trials, lean mass rose about 2.4 lb (1.1 kg) more with lifting than lifting alone |
Those strength numbers all come from people who lifted. Creatine adds to training and does very little without it. In the same 35 trials, people who took it without exercise gained essentially nothing in lean mass.
How to know it worked
The scale can’t tell you, since it goes up for nearly everyone who loads, and how you feel is easy to fool. Pick one test you can repeat, like push-ups, a dead hang or a plank. Do it twice a few days apart before you start, so you know how much you vary on your own, then retest at week eight. If you start Monday, November 16, the retest is Monday, January 11. A change bigger than the gap between your first two tries is a real change.
5 sources
- Hultman E and others, Muscle creatine loading in men, J Appl Physiol, 1996pubmed.ncbi.nlm.nih.gov
- Kreider RB and others, International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine, JISSN, 2017pmc.ncbi.nlm.nih.gov
- Rawson ES and Volek JS, Effects of creatine supplementation and resistance training on muscle strength and weightlifting performance, Journal of Strength and Conditioning Research, 2003pubmed.ncbi.nlm.nih.gov
- Delpino FM and others, Influence of age, sex, and type of exercise on the efficacy of creatine supplementation on lean body mass, Nutrition, 2022pubmed.ncbi.nlm.nih.gov
- Powers ME and others, Creatine supplementation increases total body water without altering fluid distribution, Journal of Athletic Training, 2003pmc.ncbi.nlm.nih.gov
