Should You Cycle Creatine? What the Research Says

In short: Many people still “cycle” creatine, taking it for a few weeks and then stopping for a break. Current research doesn’t support doing this. Studies in people show creatine doesn’t permanently switch off your body’s own production, muscle levels don’t drop below normal when you stop, and daily use for years appears safe in healthy adults.

An earlier version of this article suggested that cycling on and off creatine “might be a good idea.” That was a reasonable guess back in 2013, when there was less long-term data. The evidence has caught up since then, and it points the other way. Here’s what the research shows now.

What does it mean to cycle creatine?

To cycle creatine means taking it for a set period (often 6–12 weeks), then stopping for a few weeks before starting again. The idea is borrowed from other supplements and drugs where the body can get used to a substance over time.

The usual reasons given for cycling creatine are:

• to stop your body from “forgetting” how to make its own creatine
• to stop your muscles from becoming less able to absorb it
• to give your kidneys or liver a rest

Let’s look at each of these.

Does creatine switch off your body’s own production?

Your liver and kidneys make some creatine every day from three amino acids (the building blocks of protein). You also get some from meat and fish. While you’re taking a supplement, your body makes a bit less of its own. That’s normal and is the same thing that happens when you eat a lot of meat.

The key question is what happens when you stop. In a classic study of 31 men, muscle creatine rose by about 20% after six days of 20 g a day. When they stopped, it gradually fell back to its starting level over about 30 days. It didn’t drop below where it started [1]. The International Society of Sports Nutrition (ISSN), a professional organization of sports nutrition researchers, reviewed the evidence in 2017. It reported that levels generally return to baseline within 4–6 weeks, and that there’s no evidence of long-term suppression of the body’s own creatine production [2].

So taking a break doesn’t “reset” anything. It just means your muscles slowly lose the extra creatine you built up.

Do your muscles stop absorbing creatine over time?

Creatine gets into muscle cells through a “creatine transporter,” a protein in the cell wall that acts like a doorway. Some animal studies found that very high doses, around 5–10 times what people normally take, reduced the number of these transporters [3].

Human studies at normal doses haven’t found the same thing. A set of three small controlled trials looked at young men taking creatine for two months, older adults taking it for four months, and young adults doing a short loading phase. None of them showed a drop in transporter levels, and muscle creatine stayed raised throughout [3]. These were small studies (8–14 people per group), so they aren’t the final word, but they don’t support the main reason people give for cycling.

Is long-term daily creatine safe?

Creatine is one of the most studied supplements available. In one study, 98 college football players were followed for up to 21 months. Those taking about 5 g a day showed no meaningful differences in 69 blood and urine health markers, including kidney and liver tests, compared with those not taking it [4].

The ISSN position stand concluded that short- and long-term use, in studies lasting up to five years, appears safe and well tolerated in healthy people [2]. The US National Institutes of Health (NIH) Office of Dietary Supplements also notes that evidence suggests several years of use is safe in healthy adults [5]. A 2021 expert review found no harm to kidney function in healthy people taking recommended doses [6].

The most common side effect is weight gain of around 1–2 kg (about 2–4 lb), mostly from extra water stored in muscle, especially during a loading phase [5]. Some people also report stomach upset with large single doses [6].

One important caveat: people with existing kidney disease, or who take medicines that affect the kidneys, should talk to their doctor first. Most safety studies were done in healthy people. You can read more in our article on long-term creatine supplementation and side effects.

What about creatine and blood sugar?

The original version of this post was built around one study on creatine and glucose (blood sugar) handling. That research is still interesting, so here’s an updated look.

GLUT4 is a protein that moves sugar from your blood into your muscles, mostly in response to insulin and exercise. When you stop training, GLUT4 levels drop. In one study, middle-aged adults trained for 12 weeks and then 10 of them stopped exercising completely. After just two weeks off, their GLUT4 levels and insulin sensitivity were back to untrained levels [7].

In 2001, researchers put one leg of 22 healthy young adults in a cast for two weeks, then had them do 10 weeks of leg strength training. In the placebo group, GLUT4 fell by about 20% during immobilization. In the creatine group it didn’t fall, and it rose by about 40% during retraining. Muscle glycogen (stored sugar) and creatine were higher in the creatine group after three weeks of training, but the difference had disappeared by week 10 [8].

The old post read that fading glycogen effect as a hint that the body “adapts” to creatine, so taking breaks might help. That’s a stretch. The study wasn’t designed to test cycling. The creatine dose was also cut from 15 g to 5 g a day partway through, which could explain the smaller difference later on. Most importantly, the GLUT4 benefit didn’t fade.

Since then, a small 12-week trial in 25 people with type 2 diabetes who were also exercising found that 5 g of creatine a day improved HbA1c (a measure of average blood sugar over the past few months) compared with placebo [9]. It’s a promising early result, but it was one small study. It doesn’t mean creatine is a treatment for diabetes. Anyone managing blood sugar should talk to their doctor before trying it.

Does it matter what you take creatine with?

Taking creatine with a large amount of carbohydrate can boost how much your muscles store. In one study of 24 men, adding about 93 g of simple sugars to each 5 g dose raised muscle creatine 60% more than creatine alone, probably because of the extra insulin [10]. Another study found that taking creatine with carbohydrate after exercise also helped muscles store more glycogen [11].

That said, 93 g of sugar four times a day isn’t practical or healthy for most people. Taking creatine with a normal meal is a simpler option. For more detail, see our post on creatine uptake with carbohydrates.

So how should you take creatine?

Based on current research [2, 6], the most common approach is:

• Daily dose: 3–5 g a day. Over about four weeks this fills your muscles about as much as a loading phase does [1, 6].
• Loading (optional): about 20 g a day, split into four 5 g doses, for 5–7 days. This fills your muscles faster but is more likely to cause short-term water weight and stomach upset.
• Form: creatine monohydrate is the most researched form. Pricier versions haven’t been shown to work better (see our post on Kre-Alkalyn vs. creatine monohydrate).
• Breaks: not needed. If you do stop, for travel or any other reason, nothing bad happens. Your levels just drift back to normal over about a month.

The bottom line

If you’d like to cycle creatine, it isn’t harmful, but there’s no good evidence it does anything useful. The main worries behind it (shutting down your own production, muscles becoming “resistant,” or strain on healthy kidneys) haven’t held up in human studies. For most healthy adults, a steady 3–5 g a day is the simplest, best-supported approach.

This article is for general information only and isn’t medical advice. Talk to your doctor or another qualified health professional before starting a new supplement. See our medical disclaimer.

References

1. Hultman E, Söderlund K, Timmons JA, Cederblad G, Greenhaff PL. Muscle creatine loading in men. Journal of Applied Physiology. 1996;81(1):232-237.
2. Kreider RB, Kalman DS, Antonio J, et al. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. Journal of the International Society of Sports Nutrition. 2017;14:18.
3. Tarnopolsky M, Parise G, Fu MH, et al. Acute and moderate-term creatine monohydrate supplementation does not affect creatine transporter mRNA or protein content in either young or elderly humans. Molecular and Cellular Biochemistry. 2003;244(1-2):159-166.
4. Kreider RB, Melton C, Rasmussen CJ, et al. Long-term creatine supplementation does not significantly affect clinical markers of health in athletes. Molecular and Cellular Biochemistry. 2003;244(1-2):95-104.
5. National Institutes of Health, Office of Dietary Supplements. Dietary Supplements for Exercise and Athletic Performance: Fact Sheet for Health Professionals.
6. Antonio J, Candow DG, Forbes SC, et al. Common questions and misconceptions about creatine supplementation: what does the scientific evidence really show? Journal of the International Society of Sports Nutrition. 2021;18(1):13.
7. Houmard JA, Tyndall GL, Midyette JB, et al. Effect of reduced training and training cessation on insulin action and muscle GLUT-4. Journal of Applied Physiology. 1996;81(3):1162-1168.
8. Op ‘t Eijnde B, Ursø B, Richter EA, Greenhaff PL, Hespel P. Effect of oral creatine supplementation on human muscle GLUT4 protein content after immobilization. Diabetes. 2001;50(1):18-23.
9. Gualano B, de Salles Painneli V, Roschel H, et al. Creatine in type 2 diabetes: a randomized, double-blind, placebo-controlled trial. Medicine and Science in Sports and Exercise. 2011;43(5):770-778.
10. Green AL, Hultman E, Macdonald IA, Sewell DA, Greenhaff PL. Carbohydrate ingestion augments skeletal muscle creatine accumulation during creatine supplementation in humans. American Journal of Physiology. 1996;271(5 Pt 1):E821-E826.
11. Robinson TM, Sewell DA, Hultman E, Greenhaff PL. Role of submaximal exercise in promoting creatine and glycogen accumulation in human skeletal muscle. Journal of Applied Physiology. 1999;87(2):598-604.