Does Creatine Cause Water Retention?

As William Shakespeare (probably) said, “to Creatine? Or not to Creatine? That is the question.” 

It seems like we’re asking that question a lot these days. But even with decades of positive data behind it, Creatine will always have its detractors. Amongst safety profile concerns and alleged side effects, there’s still a belief that all Creatine does is make you gain water weight. 

To be fair, a “watery” or “bloated” physique is probably not something people are actively working for. Most people wouldn’t assume water retention could actually help you gain muscle or strength, either. 

But does this critique hold any water? Or is this yet another myth about Creatine that we should flush away?

How Do You Respond?

If you’ve been able to swim through my river of water puns thus far, you’ll find yourself floating up against something known as the Creatine response spectrum. This largely depends on how much Creatine your body naturally stores in the first place. 

Creatine’s primary mechanism of action is to saturate Phosphocreatine stores to help recycle ATP and fuel high-intensity performance. But about 20-30% of users end up having naturally saturated Creatine stores, or have a lower percentage of the type II muscle fibers that tend to store the most Creatine. These types of users have been dubbed “non-responders,” and tend to experience less than 10% of dry mass additional Creatine storage in their muscle tissue.

However, “responders” make up a much larger chunk of the population, which has been reflected in research for the past 40+ years. Hultman et al. found a loading protocol of 20g of Creatine taken daily for six days increased levels of total body water. Other short-term studies found increases in water retention in just three days’ time. If you’re seeing gains of ~1-2 kg (~2-4 lbs) in scale weight in the early days of supplementing (especially when loading), that’s a good sign you’re a responder.

How does Creatine go about turning you into a sentient water balloon? Creatine is what’s referred to as an “osmotically active substance.” It has the ability to encourage the movement of fluid across membranes. Creatine’s vehicle of choice to be taken up from circulation into muscles is a sodium-dependent transporter. Water then hitches a ride with the sodium being transferred to maintain the proper concentration of electrolytes within muscle cells.

So in a week’s time, you’ve already put on a few pounds if you’re a responder, and rightly deduce that you couldn’t have possibly added pounds of new muscle mass so quickly (although we can all dream…). 

This water weight must be useless, right?

Not exactly.

Turning Water Into Wine

Total body water is actually a sum of two parts: intracellular water (ICW) and extracellular water (ECW). This is water stored “within cells” and “between cells,” respectively. Remember, part of Creatine’s magic is its ability to influence fluid movement between these two spaces.

Several studies [2, 3] have shown that supplementing with Creatine only ends up having significant effects on measures of ICW. ECW is largely unaffected, except for one caveat we’ll discuss later. Functionally, this means that an increase in ICW is muscle mass. This fluid gain isn’t cosmetic; fluid itself is being absorbed into the cellular membrane of your muscles, increasing their volume.

Luckily, from an anabolic perspective, cellular hydration and swelling are… pretty swell. Putting a cell in a fully volumized state has been linked to increased rates of protein synthesis and anti-catabolic effects. In fact, some researchers have posited that increased cell volumization “may be the first step in muscle protein synthesis.” 

Creatine supplementation has also been shown to increase intramuscular concentrations of insulin-like growth factor 1 (IGF-1). IGF-1 is not only directly anabolic, but can also lead to the recruitment of satellite cells to spur additional growth. Further, Creatine can upregulate expression of specific myogenic regulatory factors (MRFs) that can directly enhance strength and performance.

Creatine may even downregulate myostatin, which is essentially the genetic governor on how much and how quickly your natural muscle growth process occurs. When it comes to gains, Creatine says “to hell with checks and balances!”

Note that these effects aren’t seen to the same degree in placebo groups completing the same programs without using Creatine.

Does Creatine Water Weight Go Away?

The increase in ICW will subside once you stop supplementing with Creatine. But having learned what we have to this point, would you really want it to? Besides the benefits, there also tends to be a minimal impact on aesthetics from gains in ICW. That is, if it’s even observable in the first place. You’re looking at giving up tons of potential benefits for something you can likely deem a nuisance in name only.

Wrapping it All Up

Looks like we can put another feather in the cap for the King of Legal Supps (trademark pending). The water retention responders see from Creatine should actually be welcomed with open arms, considering all of the ways it can aid in muscle growth. 

There are circumstances where supplementing with Creatine can cause some digestive issues. This can easily be mitigated by keeping your daily dose to 5g/day. Loading protocols that call for 20g+ a day may make it easier to gauge if you’re a responder or not and expedite the benefits of supplementing, but the end result over time is ultimately the same.

Believe it or not, if you do experience actual bloating and retention of ECW, this is probably a good sign too. This likely indicates you are absorbing a lot of Creatine. You simply need to hydrate more in order for enough water to be pulled along with the Creatine into ICW.

Almost any way you cut it, supplementing with Creatine is a net-positive if you’re a responder. If you’re a non-responder, or a competitive athlete who needs to make weight prior to specific events, then you may want to save the money and bypass Creatine altogether.

For anyone not in those categories, though, it’s all aboard the gains boat! Or… you’ll be swimming in gains! Or… you know what, I’m done with water puns now, I promise.

If you enjoyed the supp science presented here, check out Menno’s Online PT Course. You can learn about this and so (so) much more.