BCAAs, also known as branched-chain amino acids, are one of the most popular supplements for athletic performance.
These three amino acids have been shown to promote muscle recovery and growth, increase energy for endurance performance, and potentially reduce muscle soreness.
But, do BCAAs disrupt sleep or cause insomnia?
Is it okay to take BCAAs before bed or will BCAAs keep you awake?
Keep reading to find out about what the science says about BCAAs and sleep.
Do BCAAs Impact the Brain?
The three BCAAs are leucine, isoleucine, and valine.
These amino acids have a unique chemical structure that includes a long chain branching off the side.
As such, the metabolism and utilization of BCAAs differs from regular amino acids found in proteins.
How BCAAs affect neurotransmitters involved in sleep
We often think about the role of protein and its constituent amino acids in helping build and repair muscle, but amino acids have many roles in the body.
These building blocks of protein can also interact with the brain, causing changes in mood and energy levels, which in turn can impact sleep quality and quantity.
For example, tryptophan is an amino acid that is well-known to promote relaxation and sleepiness.
Tryptophan has been found to cross the blood-brain barrier where it can bind with receptors in the brain that increase the production of a molecule known as 5-HTP.
Through a series of reactions, 5-HTP then produces serotonin, which is a precursor to melatonin, a hormone that is inextricably involved in the sleep-wake cycle.
Interestingly, even though BCAAs have a different chemical structure than tryptophan, BCAAs have been shown to compete for the same binding sites in the brain as tryptophan.
When BCAAs competitively bind instead of tryptophan, it prevents the reactions that eventually produce melatonin.
This is one of the primary reasons why BCAAs are thought to boost energy and decrease feelings of lethargy and perceived exertion during endurance exercise.
If BCAAs bind in the brain instead of tryptophan, there won't be as much serotonin and melatonin production, which means you won't get as tired.
While this can be beneficial during prolonged exercise or during the daytime, it has the potential to cause wakefulness and difficulty sleeping before bed (when you want the sleepiness-inducing compounds).
Indeed, some survey research has found that a higher BCAA intake is associated with later sleep onset in adults.
That said, BCAAs may also impact the production of other neurotransmitters such as GABA and glutamate, which are also involved in sleep.
To this end, some studies have found that BCAAs improve sleep quality, potentially by modulating the levels of GABA and glutamate.
For example, one study found that a higher intake of BCAAs and aromatic amino acids (like tryptophan) improved sleep quality and duration in normal weight adults but not adults with obesity.
There is still not enough evidence to conclusively determine the impact of taking BCAAs at bedtime on sleep.
Your overall diet, including your carbohydrate intake and overall protein intake, also seem to impact the effects of BCAAs on sleep.
BMI, or body weight, may also influence if and how BCAAs improve sleep or cause symptoms of insomnia as evidenced by the aforementioned study.
Are There Stimulants in BCAA Supplements?
BCAA supplements come in a variety of formulations.
Clean BCAA supplements, like our strawberry lemonade BCAAs, may be sold as powders, pre-mixed liquids, capsules, or even gummies.
These BCAA supplements do not contain any fillers or other ingredients aside from leucine, isoleucine, and valine, typically in a 2:1:1 ratio.
Pure BCAA supplements do not contain any stimulants because amino acids are not stimulants.
However, BCAAs can be found in a variety of other sports supplements including pre-workout powders and pre-workout drinks.
Most pre-workout supplements are intended to give you a burst of energy before training, so they often contain caffeine, which is a stimulant.
Note that many pre-workout formulations also include other amino acids such as taurine and citrulline along with B vitamins, creatine, and other ingredients, but caffeine, often in the form of green tea extract or coffee bean extract, is the primary stimulant found in these products.
Energy drinks and pre-workout supplements with BCAAs may also contain guarana, another stimulant.
Timing of BCAA Consumption and Sleep Impact
There are many reasons to consider taking BCAA supplements, but understanding when to take BCAAs to maximize the benefits is important.
When is the best time to take BCAAs?
Ever since a clear consensus on the best time to take BCAAs for all individuals.
Studies have found that BCAAs before a workout can improve energy and endurance while taking BCAAs after a workout can support muscle growth and recovery.
Depending on your training goals, overall diet, and the timing of your workouts relative to your meals, it may be helpful to split your BCAA dosage by having 2.5-5 grams in the morning or before your workout and a similar dosage post-workout or later in the day.
Keep in mind that consuming a well-rounded diet with plenty of complete protein will also give your body an ample supply of BCAAs.
However, BCAAs are considered essential amino acids, which means that they must be consumed in the diet or through supplements because the body cannot manufacture them endogenously.
Managing BCAAs for Optimal Sleep and Recovery
Best time to take BCAAs to avoid interference with sleep
Some individuals are sensitive to taking BCAAs at bedtime.
Because these amino acids can compete with binding sites in the brain for tryptophan, some people do experience difficulty sleeping or other symptoms of insomnia if BCAAs are taken at bedtime, or shortly beforehand.
For example, one study found that BCAAs disrupted sleep quality and quantity in children but not adults.
If you find that BCAAs disrupt your sleep, it is recommended that you take them first thing in the morning or with breakfast to ensure that these supplements are fully metabolized long before you go to sleep.
Alternatives for BCAAs at bedtime to support sleep and recovery
Bodybuilders and strength athletes are often interested in taking BCAAs before bed to help prevent muscle catabolism, particularly during a cutting phase or when in a caloric deficit.
Leucine, in particular, has been shown to stimulate muscle growth, so having an influx of BCAAs before bed can potentially offset muscle breakdown.
Additionally, if you are training in the evening or simply undergoing high-intensity weight lifting that is breaking down your muscles, you may want to boost your protein intake before bed.
However, if you find that BCAAs keep you awake or cause sleep disturbances, consider non-stimulating recovery supplements and other amino acids.
For example, tryptophan is an aromatic amino acid that has been shown to promote sleep (think about all of the jokes and memes about needing to take a nap after a big turkey dinner!).
Casein is a protein found in supplement form as well as dairy foods such as cottage cheese.
Some studies suggest that casein protein before bed may support muscle recovery while improving sleep quality.
You can also consider pairing your bedtime recovery protein supplements with other micronutrients that aid sleep such as magnesium.
Using whole foods or other amino acids for evening recovery support
As mentioned, dairy foods such as cottage cheese contain casein protein, which can be helpful in promoting sleep before bed.
Studies also suggest that kiwi fruit, tart cherries, and milk may help promote sleep.
Milk paired with something like a banana can also be a good alternative because you get a balance of protein for recovery along with complex carbohydrates to replenish glycogen stores and natural electrolytes such as magnesium and potassium.
Bananas are also a natural source of tryptophan, the sleep-promoting amino acid.
If you prefer using supplements, consider making a protein shake with casein protein powder, milk, a banana, tart cherries, and some cottage cheese or Greek yogurt.
TL;DR: Do BCAAs Keep You Awake?
Overall, there isn't enough evidence to suggest that BCAAs cause insomnia or will keep you awake.
Some athletes are sensitive to BCAAs because they can increase energy by blocking tryptophan from binding in the brain.
If you find that BCAAs at bedtime are keeping you awake or causing restlessness, shift your schedule to have BCAAs with breakfast or before your workout and opt for other sources of protein before bed.
