Creatine: Effects, Benefits and Safety

Creatine is one of the best supplements you can take if your goal is strength and muscle growth.

Creatine has been studied in over a thousand trials, and has consistently been found to increase strength and muscle size. Furthermore, it seems to diminish muscle damage after exercise, and may enhance cognitive functions such as memory and executive functioning.

In this guide, you’ll learn what creatine is, how it works, and why you as a lifter should be interested.

Table of Contents

What is Creatine?

Creatine is a naturally occuring compound that your kidneys and liver produces every day from amino acids.

It is a molecule used as an energy reserve in especially energy consuming organs such as your muscles, where ~95% of all creatine is stored, but also in the brain.¹

About 1/3 of the creatine stored in your muscles is free creatine, with the remaining 2/3 being stored in the form of creatine phosphate. When your muscles exepend energy, in the form of the energy rich molecule ATP, creatine phosphate is used to regenerate ATP.

Your muscles stores of ATP only last for 2–3 seconds of maximal work, such as one or two very heavy lifts, at which point creatine phosphate kicks in as the quickest source of regenerating ATP.

Your stores of creatine phosphate are however only enough to regenerate ATP for 5–6 seconds of maximal work, and after 10 seconds of maximally intensive work, half of the regenerated ATP will come from creatine phosphate and the other half from glycogen.

After 20 seconds of maximal work, your stores of creatine phosphate will be almost completely depleted, and glycogen accounts for the majority of ATP-production.²

Here’s a breakdown of the process:

Your muscles contract, using ATP.
Creatine phosphate is split into free creatine + one phosphate ion, releasing energy in the process, which is used to regenerate ATP.
When you rest, the free creatine and that was already stored in your muscles and the free creatine that was produced in step 2, is used to regenerate creatine phosphate. This is done with energy from other energy systems (like the aerobic system).
It takes about 20 seconds of maximally intensive work to deplete your creatine phosphate stores completely, and about 2 minutes to regenerate these stores to 95%.

Sources of Creatine and Daily Intake

Every day, you produce about 1–2 grams of creatine out of amino acids, in your liver and kidneys. If you eat meat, fish or poultry, you’re likely getting an additional gram of creatine from your diet.

Remember that 95% of your creatine is stored in your muscles? Well, the same goes for other animals, and when you eat the animals muscles, you’ll absorb their creatine. Red meat, fish and poultry typically contains about 1–3 grams of creatine per pound (3–5 grams per kg), and a litre of milk (~1 quart) contains 0.1 g.³

This means that vegetarians does not get any (or very little) creatine from their diet, and vegetarians also have less creatine in their muscles – about 85% of the levels of people who eat meat.⁴ ⁵ ⁶

Creatine supplementation could therefore be of extra interest to those of you who seldom or never eat meat. Creatine supplements are vegetarian by the way; they are produced from amino acids without the involvement of animals.

However, even when people who eat meat, fish or poultry begin to supplement with creatine, the creatine content of their muscles increase by 20–40%. The diagram below gives you a rough idea of average creatine content in muscles of people who 1) are vegetarians, 2) eat meat, fish or poultry, or 3) have supplemented with creatine.

So, if you start eating more creatine in your diet or supplement with it, your muscle creatine content will rise.

Effects of Extra Creatine

The increased amounts of creatine in your muscles means that you have more rapidly available fuel to use for short burst of high intensity activites, like lifting weights or sprinting.

More creatine in your muscles means that you might be able to do a few extra reps per set, or do a similar amount of reps as before but with a heavier weight. You’ll also recover quicker between sets, and can perform a larger total volume of work during your workouts. This will in turn lead to a greater training stimulus, with potentially greater gains of muscle mass and strength as a result.⁷ ⁸

How much greater gains?

Let’s break it down into four different aspects:

Strength
Strength endurance
Muscle growth
Recovery

Creatine – Effect on Strength

A review of 22 training studies found that participants who were given placebo increased their strength by 12% on average during the training, while participants who were given creatine increased their strength by 20%. In strength tests where the participants did as many reps as possible on a given % of their max, the placebo-groups increased their performance by 12% on average, while the creatine groups increased by 26%.⁹

This was in studies lasting 2–3 months on average.

The increased strength gains from creatine is thought to be an effect of the enhanced training you can do while supplementing – you can do more reps with heavier weights, and maybe also recover faster (more on that later).

The performance enhancing effect on 1RM after supplementing with creatine during a training period is well established, but does creatine also have an “acute” effect on 1RM strength, which is seen as soon as you have loaded up on creatine – i.e after a 5–6 day loading phase with 20 g/day?

There are a small number of studies that support that.¹⁰ ¹¹ This contrasts with the hypothesis of increased performance only via increased creatine phosphate, since lack of creatine phosphate will probably not be an issue in a 1RM test. But, the results might simply be chance: the number of studies are few, with few participants, low statistical power and small effects.

As of now, the only thing we know for sure regarding the effect of creatine on maximal strength is that when athletes supplement with creatine during their training, they gain more strength than otherwise.

Creatine – Effect on Strength Endurance

Creatine is your muscles fastest way to regenerate ATP, and the primary energy source for short-term high-intensity work. Creatine supplementation increases the content of creatine in your muscles, which makes it ideal for enhancing performance not only in strength endurance tasks (typically lasting less than a minute), but also in repeated high-intensity efforts, like the repeated sprints that occur in many team sports like football or soccer, for example.¹²

Cycling (Wingate test): Creatine supplementation (2–5 g/day) have been found to increase mean and peak power output during 30s Wingate Anaerobic Test compared to placebo, in both football and soccer players.

The acute endurance effect is not exclusive to sprints or intensive cycling:

Bench Press: After supplementing with 25 g of creatine for 6 days, resistance trained men significantly increased their number of reps performed in the bench press during 5 sets to failure with 10RM-loads, compared to placebo.

An example of creatines effect on strength endurance can be seen in the diagram adapted from Izquierdo (2002) below.

Creatine supplementation acute effect on bench press endurance

It shows the results before and after five days of creatine supplementation (20 g/day) in bench press performance, where the participants where instructed to do as many and as powerful reps of bench press as possible. The diagram shows the results of the group that received creatine, who significantly increased their performance. The group that received placebo didn’t see any improvement at all during the five days between the tests.

Note that the diagram shows the second set of bench press – the first set was only a pre-exhaustion set of 10 reps, designed to test endurance and recovery to the second test. That explains why the creatine group could lift with more power from the first repetition: they hadn’t become stronger – they where just more recovered from the first set in the “after”-test.

Contrary to 1RM strength, the positive effect on short-term, high-intensity activites are acute – meaning that after a loading phase of 5–7 days with 4 x 5 grams of creatine per day, a small effect is already seen. This is because as soon as you have increased your muscles stores of creatine, you can put it to use.

In addition to the short-term effect, creatine likely also have a long-term effect: if you can train faster, harder, and recover more quickly, this will enable you to get a better training stimulus and thus better long-term results. The acute effect of increased fatigue resistance will vanish once you cease taking creatine, but not your hard-earned, long-term training results.

When is creatine no longer beneficial for endurance?

Creatine supplementation aids your phosphocreatine-system, which only lasts for about 20–30 seconds of high-intensity work before glycolysis takes over as the main energy source.

Creatine supplementation has been found to aid performance in activities lasting less than 3 minutes,¹³ ¹⁴ but the effect is likely larger the closer you are to phosphocreatines 20–30 seconds worth of stores, or say <1 minute – which is coincidentally right around the same amount of time it takes to perform a typical weight training set of 8–20 reps.

Creatine – Effect on Muscle Growth

When it comes to the effect of creatine on muscle growth, it’s a bit harder to distinguish the lean mass gains from creatine loading on it’s own, from it’s beneficial effect on muscle growth.

A common misconception about creatine is that it will make you look bloated or watery and appear less lean, but the opposite is true: 95% of creatine is stored in your muscles, so creatine loading will rather make you appear more muscular. In one study, 10 days of creatine loading increasead the diameter of type I, IIa and IIx muscle fibers in the quadriceps by 9%, 5% and 4% respectively.¹⁵

Lean mass typically increase by up to 1–2% from creatine loading, but the extra muscle growth compared to control groups seem to be larger than what could be explained by the loading effect alone. A meta-analysis of 18 training studies which compared creatine to placebo, found that during the studies (which on average lasted 8 weeks) the placebo groups increased their lean mass by 0.20% per week, while the creatine groups increased lean mass by 0.56% per week – a difference of 0.36% per week. It is reasonable to assume that some of this extra lean mass compared to the control groups might be lost if the participants stopped taking creatine, but not all of it.¹⁶

A more recent study had 43 resistance-trained men train for 8 weeks, while either getting placebo or creatine. The creatine group received about 20 g/day for the first week, and then about 2 g/day for an additional 7 weeks. The result is shown in the diagram below: the creatine group increased their lean mass significantly more than the placebo group, measured with DXA.¹⁷ Again, some of this gain is probably due to the increased stores of creatine itself, but likely not all of it.

Lean mass increase after creatine Nunes 2017 vs placebo

The increase was largest in the arms. It is unclear if this is because the arms benefit more from creatine supplementation than the legs do. An earlier meta-analysis did indeed find that performance gains from creatine supplementation were larger in the upper body than the lower body.¹⁸ It might also simply be explained by the fact that the particular training program used in this study had quite a bit larger training volume for the arms than for the legs. As creatine augments training results, the higher volume might conceivably benefit the creatine group.

Creatine – Effect on Recovery

Except greater strength and muscle gains, creatine supplementation has been found to enhance recovery after training. Studies have shown that participants who supplemented with creatine regained full muscle function quicker, and showed less markers of muscle damage after hard workouts or strenous training periods.¹⁹ ²⁰ ²¹ ²²

This points towards creatine being one of very few supplements that can actually aid your recovery. Theoretically it could mean that you can train with a larger volume or higher frequency while supplementing with creatine, without exceeding your recovery capabilities.

Dosage of Creatine: How Much Should You Take?

Probably the most common way to dose creatine is to begin with a loading phase where you take 20 g/day (split in 4 doses x 5 g) for 4–6 days, followed by a maintenance phase where you take 3–5 g/day every day.

The purpose of the loading phase is to load the muscles with creatine in a shorter time than it would take if you’d go straight into the maintenance phase. The end result will be the same – the only difference is how fast you reach the creatine loaded state.

An early study²³ demonstrated the difference between dosing strategies of creatine in a clear way, using four groups of participants:

One group who took 20 g/day (split in 4 x 5 g) for 6 days, and no more after that.
One group who took 20 g/day (split in 4 x 5 g) for 6 days, and then 2 g/day for 28 additional days.
One group who took 3 g/day for 28 days.
One group who only received placebo.

They used creatine monohydrate, and the participants were physically active young men with a bodyweight around 170 lbs or 75–80 kg.

The results?

Group 1 who received 20 g/day for 6 days and then nothing more, increased their muscle creatine content by 18% after those 6 days, but during the following 28 days, the creatine content gradually decreased. On day 35 (after 28 days without creatine) they had about as much creatine in their muscles as before the study – just a non-significant 7% increase was still there.
Group 2 who received 20 g/day for 6 days and then 2 g/day for 28 days, increased their muscle creatine content similarily to group 1: 21% increase after 6 days with 20 g/day. But, differently from group 1, they maintained this creatine content throughout the following 28 days (where they received 2 g/day).
Group 3 who received 3 g/day for 28 days gradually increased their muscle creatine content throughout the study: 12% increase after 14 days, and 17% total after 28 days.

So – how low can you go?

A study on non-vegetarian female swimmers failed to see any difference in muscle creatine content (or performance) compared to placebo after six weeks of 2 g/day creatine supplementation.

It would seem that ~2 g/day is right around the lower limit for an effective dose. The standard “safe” dose for performance enhancement is 5 g/day, but it seems 3 g/day (a teaspoon of creatine) is sufficient for many.

We therefore recommend a daily dose between 3–5 g/day – where you might err on the higher end if you have a very large muscle mass and/or don’t eat a lot of meat.

A loading phase of 20 g/day for 4–6 days is not necessary, but will load your muscles with creatine faster – in a week, as opposed to 3–4 weeks of 3–5 g/day. Divide the 20 g into 4 x 5 g doses spread evenly throughout the day.

Different Types of Creatine

Creatine is a white, cristalline powder that tastes like sand and is water soluble. Creatine monohydrate is the variant with highest creatine content, and it takes 12 fl oz (3.5 dl) of water at 68°F (20°C ) to completely solve 5 g of creatine monohydrate. Some other forms of creatine, such as creatine citrate and pyruvate, have higher water solubility, but does not differ in absorption or effect otherwise.

Creatine monohydrate is the most common and by far the most studied (97%+ of studies) form of creatine, and no other form of creatine have been found to be more effective. In the best cases they are equally effective but at a higher cost – in the worst case they are not only more expensive but also have a worse effect.

In 2011, a review of all scientific litterature regarding different forms of creatine supplements was performed, and this was their conclusion:

”There is little to no evidence supporting marketing claims that these newer forms of creatine are more stable, digested faster, and more effective in increasing muscle creatine levels and/or associated with fewer side effects than CM [Creatine Monohydrate].”
Jäger (2011)²⁴

Only in one aspect is there a relevant (well, sort of) difference between the different forms, and that is water solubility. Since various myths and misunderstandings arise from this difference, let’s adress it.

Water Solubility of Different Forms of Creatine

Creatine monohydrate consists of 87.9% creatine, which is the highest creatine content of all creatine supplements – the closest you’ll get to pure creatine. It has a moderate water solubility, which is highly influenced by the water temperature.

One litre of water dissolves:

6 g of creatine monohydrate at 4°C
14 g at 20°C
34 g at 50°C

You probably know what unsolved creatine looks like: white, grainy sand on the bottom of your water glass.

Some other forms of creatine show better water solubility, such as creatine citrate and creatine pyruvate. Here’s how their solubility stack up against creatine monohydrate:

Creatine monohydrate: 14 g/L at 20°C
Creatine citrate: 29 g/L at 20°C
Creatine pyruvate: 54 g/L at 20°C

This means that you could mix your creatine citrate or pyruvate in less water than you would mix monohydrate, and it would still dissolve completely. However, both creatine citrate and pyruvate contain less creatine than creatine monohydrate – creatine monohydrate contains 87.9% creatine, citrate 66% and pyruvate 60% – so you would need to increase the number of grams of powder you take, which would require additional water. The end result will still be that you’ll need slightly less water for a dose of creatine from citrate and pyruvate, but only like a couple of ounces / a decilitre or so.

Does it matter?

In my personal opinion: No. At least not enough to warrant the difference in price.

I’d wager that most people who take creatine doesn’t even use enough water to dissolve it to begin with, and for most people that works just fine. Your stomach is full of fluids, and if you don’t dissolve your creatine in enough water in your glass, it will simply dissolve in your stomach contents instead.

Some people might be more sensitive to mixing creatine with too little water, however. Read more about this in the section on side effects below.

To recap: there are some forms of creatine that dissolve more easily in water. This does not affect how they increase your muscle creatine content, it does not affect water retention, and it does not affect performance enhancements.

The form of creatine we recommend is creatine monohydrate.

Creatine Safety and Side Effects

Creatine supplementation has been studied rigorously for decades, in over a thousand studies, and have consistently proven to be safe and without any adverse effects on clinical health markers – even in long-term studies lasting up to five years.²⁵ ²⁶ ²⁷ ²⁸

A systematic review and meta-analysis published in 2019 investigated the effect of creatine supplementation on renal function, and concluded that is has no adverse effects.²⁹

In the few case-reports reporting adverse effects in patients using creatine, many contain confounding factors, such as previous renal disease, steroid-use or overdosing. As an example, a patient submitted with an inflammation in his kidneys reported continuously taking a “large quantity” of anabolic-androgenic steroids and 200 grams of creatine per day.³⁰

For healthy people, using normal doses (as discussed earlier in this article), over 30 years of research and more than a thousand studies suggest that creatine is a safe supplement.

Safe, however, is not the same as free of side effects. There are two reported side effects of creatine:

Weight gain
Stomach discomfort

Weight Gain

When you take extra creatine, you increase the amount of creatine stored in your muscles by about 20–30%. This creatine is bound in your muscles with water, just like glycogen.

As a consequence, body weight has been found to increase by up to 1–2% after 28 days of creatine supplementation (a loading phase of 25 g/day for 7 days (loading phase) and 5 g/day for the remaining 21 days).³¹

In many cases, however, no significant increase is observed at all. In a recent meta-analysis, 15 studies on female participants only, found no significant body weight increase from creatine supplementation.

Creatine binds with water and is stored in your muscles, but this doesn’t seem to lead to significant weight gains in everyone, and up to 1–2% at most.

Stomach Discomfort

Various forms of gastrointestinal distress such as upset stomachs or even diarrhea, are uncommon in the scientific litterature where corrects dosages of creatine are given. However, “in the real world”, it seems a bit more common that people experience different kinds of stomach discomfort.

This is likely a consequence of incorrect dosing. The recommended dosing is to begin with a loading phase where you take 20 g/day (split in 4 doses x 5 g) for 4–6 days, followed by a maintenance phase where you take 3–5 g/day every day (or just skip straight to the maintenance phase, but what will require a few extra weeks before you are fully loaded up on creatine). In either case, don’t take more than 5 g at once, as 10 g per dose (but not 5 g) has been found to increase the risk of stomach discomfort compared to placebo.³²

Additionally, you need 12 fl oz (3.5 dl) of water at 68°F (20°C ) to completely solve 5 g of creatine monohydrate. Taking it with less water likely increase your risk of stomach discomfort.

Stomach sensitivity seems to differ between individuals, as some simply take a spoon of creatine in their mouth, wash it down with a sip of water, and don’t experience any problems.

If you do experience stomach discomfort from creatine, try this:

Make sure you’re only taking 3–5 g/dose. A teaspoon (the measure, i.e. 5 mL) contains 3 g of creatine. With a maximally filled actual teaspoon (not the measure) it’s easy to get 10 g of creatine in one spoon. If you wan’t to be sure, get a kitchen scale and check your dosing.
Take it with enough fluid. 12 fl oz (3.5 dl) of water at 68°F (20°C ) for 5 g of creatine – slightly less if you use a warm fluid, such as coffee or tea.
Take it with food. Take the creatine with a meal, and it will be even more diluted in your stomach, decreasing the risk of stomach discomfort.

Frequently Asked Questions About Creatine

Will Creatine Make You Look Bloated and Watery?

No.

When you start taking creatine, your body weight might increase by up to 1–2% from extra water retention. But the thing is, this is stored in your muscles. In the same way that filled stores of muscle glycogen makes you look more muscular, so will the extra creatine.

So no – creatine will not make you look watery, or bloated, or fatter. Creatine will at most make you look like you have up to 1–2% bigger muscles.

Do You Need to Drink More Water While Taking Creatine?

Probably not. Or, at least not consciously. In the study by Powers (2003) referenced above, the participants had increased their total body water by 1.4 litres after a 7-day loading phase, and by 2.0 litres (total) after the full 28 day creatine supplementation period.

1.4 litres in seven days is just 2 dL, or slightly less than a cup of water each day. If you currently are not drinking enough to support that need, you will simply be little more thirsty, which will drive you to make up for the extra water.

This is not something you need to worry about.

Should You Take Creatine While Cutting?

It depends on why you are cutting.

If you are cutting weight to make a weight class – yes, you probably should stop taking creatine. Stop taking it about a month out for all the extra creatine to leave your muscles.
If you are cutting to lose fat or look good – no, there is no reason to stop taking creatine. The creatine might make you appear up to 1–2% more muscular, and it will aid your training, enabling you to keep (or build) more muscle and strength during your cut.

Creatine enhances your training via greater stores of creatine phosphate inside your muscles, kind of like larger glycogen stores, and therefore leads to an increased lean mass (= weight).

There is no reason to cease supplementation unless you care about your total body weight in absolute numbers only.

Will You Lose Your Strength and Muscle Gains When You Stop Taking Creatine?

No. Yes. Sort of.

It depends in part on which aspects of strength and muscle gains we are talking about.

Creatine’s main effect is to increase the amount of creatine phosphate stored in your muscles, by about 20–30%. The creatine is bound with water inside your muscles, thereby increasing your lean mass by up to 1–2%, and the diameter of your muscle fibers by about 5–10%.³³ The extra creatine phosphate enhances your performance in primarily high-intensity exercise that is short-term (<1 minute) or repetitive in nature – like classic strength training or sprints – and possibly also some other effects, as discussed earlier in this guide.

If you stop taking creatine, your internal stores of creatine will revert back to your baseline (before you started supplementing) within about a month. At that point, you will no longer have the aid of the extra creatine for your training and recovery. What you will still have, however, is the extra gains you made because you had the aid of creatine. While you supplemented, you were able to train harder and better, and as a consequence could create a greater stimuli for training adaptations.

So while you might see a slight performance decrease in the month following a cessation of creatine supplementation because your creatine stores will decrease, you will still keep the training adaptations you made over the last training period.

Should You Take Creatine on Rest Days?

Yes.

Creatine works by increasing your muscle stores of creatine, which takes about 5–6 days with a loading phase of 20 g/day, or about four weeks with 5 g/day. It does not have an acute effect, meaning: you don’t see a performance increase on the same or first day you take creatine – you must first load up on it.

After you’ve loaded up on creatine, you need to maintain that level of muscle creatine to keep the effect going. That means taking 3–5 g/day every day.

What Happens if You Forget to Take Creatine a Day or Two?

Not much.

It takes about a month after you stop taking creatine to revert back to your baseline levels of muscle creatine, so one missed day does not make much of a difference.

In this study, two weeks without creatine only decreased the muscles creatine content by ~5%.

Creatine loading strategies 20g day 1-6 then zero

That means that you could go for a two-week trip without packing creatine, and still not lose much (or any) of the creatines effect when you get back home. Just resume your training and start supplementing again.

It also means that you don’t need to worry about missing the occasional day here or there. But keep missing days, up to the point that your daily average throughout the week slips below about 3 g/day for an extended period of time, and your muscles creatine stores will likely start to dwindle, which means that the effect will diminish.

Aim for 3–5 g/day, every day. Then it won’t matter if you miss an occasional day here or there.

Should You Cycle Creatine?

No.

There is no evidence to support that claim, and neither have studies on long-term creatine supplementation found any adverse health effects.

The myth likely stems from the fact that creatines effect is largest when you start taking it, due to the sudden increase in muscle creatine content, and the thinking goes that “If I stop taking creatine, I can get this performance increase again!”. Well, yeah, you can, but not without first getting the exact same performance decrease when the creatine is leaving your muscles.

If you wish to use creatine: Load up on it, maintain the dose, and just keep training hard.

Does Caffeine Counteract Creatine?

Maybe.

There is very limited research to suggest that caffeine might blunt the performance enhancing effect of creatine:

Vandenberghe (1996): This study had participants perform several 12 sets of 10–30 reps of leg extensions, with short rest between sets. The participants performed this test in three conditions: control (without any supplements), creatine only, or creatine + caffeine. The group consuming creatine only saw a slight increase in force production compared to control, while the group that consumed creatine+caffeine did not.

A suggested mechanism of why caffeine might blunt creatines effect, is because creatine shortens a muscles relaxation time, while caffeine prolongs it, and taken together the relaxation time is unchanged.³⁴

So that’s it, then? Caffeine blunts the effect of creatine?

Not so fast.

Creatine has strong evidence supporting it’s effects. So does caffeine, with a meta-analysis from 2018 showing positive effects on maximum muscle strength and power, based on 20 studies.³⁵

So does two rights really make one wrong?

The study by Vandenberghe (1996) and the abstract from Harris (2005) are as of today still the only pieces of evidence for a counteracting effect between caffeine and creatine.

On the other side, several studies have used tea or coffee to deliver the creatine, and seen increased performance during repeated high-intensity cycling sprints lasting 10–30 seconds,³⁶ ³⁷ and faster recovery of creatine phosphate after intensive exercise.³⁸

Furthermore, several multi-ingredient supplements containing both caffeine and creatine have shown positive effects on strength, power and lean mass gains.³⁹

And opposed to a blunting effect, two studies have found an additive effect of creatine combined with caffeine:

In 6 x 10 seconds cycling sprints with one minute rest intervals, creatine+placebo performed slightly better than control, and creatine+caffeine performed even better.

In longer cycling times, 3–15 minutes, which is longer durations than where creatine is generally performance enhancing, caffeine+creatine still performs significantly better than the control case.⁴⁰ ⁴¹

So – does caffeine counteract the effect of creatine?

Maybe. Maybe not. The research is sparse and points in both directions, which might be an indicator that if there is an effect at all, it could be small.

>> Click here to read our guide on caffeine.

Does Creatine Increase Your Risk of Hair Loss?

Unknown, but unlikely.

This is a common claim, with no definitive scientific evidence to back it up.

There has been no study directly investigating whether or not creatine causes hair loss, and it has not been reported in the reviews investigating creatines safety and side effects.

The rumour stems from one study⁴² where 20 rugby players underwent two different three-week supplementation periods, in randomized order:

Creatine: During this period, they received 25 g of creatine per day for a 7 day loading phase, followed by a maintenance phase with 14 days of 5 g/day.
Placebo: During this period, they received placebo throughout the three weeks.

It was a double-blind cross-over study with a 6 week wash-out period, meaning that after the supplementation period (creatine or placebo), the participants went 6 weeks without any supplement, and then were alloted to the other group.

Creatine supplementation was found to increase dihydrotestosterone (DHT), a metabolite of testosterone, by 56% after 7 days of creatine loading and remained 40% above baseline after 14 days of maintenance, while no change was seen while the participants received placebo. Even with the increase however, DHT still remained well within normal levels during the creatine supplementation period.

This increase in DHT is relevant because DHT has been implicated to have an important role in male pattern hair loss.⁴³ ⁴⁴

This study is still the only one that have investigated the effect of creatine on DHT. We don’t even know if the increase is an effect we would see if the study was replicated. Personally, I am sceptic to the seemingly dramatic increase in DHT in this study, because:

This was a cross-over study, meaning that the same people went through both protocols, separated with a 6-week wash-out period, enough to dissipate any remaining creatine.
Despite consisting of the same participants, the placebo-group had 29% higher DHT at baseline compared to the creatine group – 0.98 (creatine) vs 1.26 (placebo) nmol/L. That is, before they even started taking creatine or placebo.
This difference in baseline makes the 53% increase seem more dramatic than it is: after three weeks of creatine supplementation, the DHT-levels of the creatine group (1.38 nmol/L) is only 10% over the placebo groups baseline level of DHT (1.26 nmol/L).

When the participants underwent creatine supplementation, they also saw a non-significant increase in testosterone of 15%. That is an effect that is generally not seen in studies that have examined the effect of creatine on testosterone, which furthers the case that something might be amiss with the baseline levels in this study.

So does creatine increase your risk of hair loss?

Well, no one knows for sure – it has never been investigated. But the saying “extraordinary claims require extraordinary evidence” comes to mind. Considering that …

Creatine typically does not seem to influence testosterone.
Hair loss has not been reported as a side effect in the scientific literature.
There’s only one study investigating creatines effect on DHT, and in that one the same participants differed 29% in DHT-levels at baseline (0.98 nmol/L vs 1.26 nmol/L for creatine and placebo, respectively), and that after creatine supplementation DHT was only 10% higher (1.38 nmol/L) than at baseline for placebo, while still well within the normal range of 0 to 3.3 nmol/L

… I personally make the conclusion that while it is still possible that creatine might be implicated in accelerating hair loss in those predispositioned for it, it is as of yet unknown, but unlikely.

How Does Creatine Affect Cognitive Function?

The brain is one of our most metabolically active organs, responsible for about 20% of our resting energy expenditure, despite only accounting for 2% of our body weight. While 95% of the creatine in our bodies are stored in muscles, much of the rest is stored in, and used by, our brain.

Just like our muscles, our brain uses creatine for quick access to energy. And also like our muscles, when we supplement with creatine, we increase the creatine content of our brain.⁴⁵

While creatine is currently used to treat medical conditions that cause creatine deficiency in the brain, it is being researched as a mean to relieve symptoms or slow the degradation in brain-related diseases such as Huntingtons, Parkinsons, ALS or traumatic brain injuries. This might be the explanation for a recent surge in interest for the effect of creatine supplementation in cognitive functioning in healthy individuals.

While the evidence is still limited and many gaps needs to be filled, recent systematic reviews have found that creatine supplementation may improve performance on memory and reasoning tasks.⁴⁶ It also seems that the positive effect of creatine is greater when the brain is stressed in one way or another; whether through sleep deprivation, or more complex and fatiguing cognitive tests.⁴⁷

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That’s it! You’ve reached the end of our guide on creatine.

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