Does creatine affect your sleep?
Creatine may improve how your sleep feels, but objective measurements show no effect. Do not use it primarily as a sleep aid; if you are already taking it for sport, you need not expect worse sleep.
Creatine appears to improve how you experience your sleep. In a small study with 14 men, participants who took 20 grams of creatine per day for one week scored significantly better on a sleep quality scale than the placebo group. The effect was medium-sized and they also went to bed earlier. However, this is a single small study, so it should not be given too much weight.
What you feel yourself and what a device measures diverged in that same study. Objective measurement via a motion sensor worn on the wrist showed no difference whatsoever in how long it took to fall asleep, how efficiently participants slept, or how long they slept. Creatine may therefore change how your sleep feels without actually shifting the underlying sleep structure.
A second small study, involving 21 women who took 5 grams of creatine per day alongside strength training for six weeks, showed a slightly different picture. On training days, women in the creatine group slept significantly longer than women taking a placebo. On rest days and on the general sleep quality scale there was no difference. At most, this points to a recovery effect after exercise, not a broad sleep benefit.
There are also indications that creatine partially protects the brain against the effects of sleep deprivation. Creatine acts as a rapid energy reserve in the brain, which can be useful when you are short on sleep. A review article concludes that creatine supplementation can partially offset cognitive decline caused by sleep deprivation or ageing. The researchers themselves stress that the findings are preliminary and inconsistent.
As an additional effect, creatine also reduced muscle soreness after exercise. This could indirectly improve sleep, but that link has not been directly investigated in the available studies.
All findings come from two small studies (14 and 21 participants) and one review article. None of the studies is large enough to support firm conclusions. The fact that objective measurements did not align with subjective improvements makes interpretation particularly difficult.
What does alcohol do to the quality of my sleep, and is there anything that can be done about it?
Alcohol helps you fall asleep faster, but measurably disrupts the rest of your night, even with just two drinks. If you want to sleep better, drinking less or no alcohol before bed is the most effective step.
Can sleep deprivation raise your blood pressure?
Chronically sleeping too little is associated with a clearly elevated risk of high blood pressure. If your blood pressure is raised and you are structurally sleeping too little, that is a good topic to discuss with your doctor.
Chronic sleep deprivation: how harmful is it for weight and hormones?
Chronic sleep deprivation disrupts your hormones and metabolism after just a few nights. Structurally sleeping too little increases the risk of weight gain, muscle loss and diabetes.
Does taking glycine help you sleep better?
Glycine shows tentatively positive signals, but the evidence is thin and the only direct human study comes from the manufacturer itself. Anyone who wants to try it would be wise to view it as a complement to good sleep habits, not a replacement.
Does creatine affect dopamine levels?
In healthy people, creatine has no demonstrable effect on dopamine in the blood. Positive signals so far come exclusively from mouse research.
Does creatine also help with memory and concentration?
Creatine can improve your memory, but mainly if you are older, vegetarian, or your brain is under pressure. If you are a young, healthy meat-eater who sleeps well, the effect is small to negligible.