Branched chain amino acids: what they are for and when to take them

aminoacidi ramificati a cosa servono quando assumerli

The amino acids

Amino acids are responsible for carrying out important and multiple functions related to cellular metabolism but above all they represent the fundamental components of proteins, essential for normal growth and proper development of the human body.

They contain both an acid group (usually a carboxylic group, -COOH) and an amino group (NH2).

Based on their role in metabolic processes and the ability of the human body to produce them, amino acids are divided into: essential, conditionally essential and non-essential.

Essential amino acids cannot be synthesized by the body and therefore must be taken through the diet or specific supplements.

To this group belong 10 amino acids: tryptophan, valine, leucine, isoleucine, lysine, phenylalanine, methionine, threonine, carnitine and histidine.

The conditionally essential amino acids are not indispensable for survival and are not necessarily required by the diet as the human being is able to produce them through specific reactions, at certain stages of development or in the course of life and according to needs.

In particular pathophysiological conditions their synthesis can be compromised to the point of requiring supplementation. This group includes 6 amino acids: asparagine, arginine (discover Arginine AKG), glutamine, glycine, proline and tyrosine.

Non-essential amino acids (such as taurine and the citrulline) instead are those that the body synthesizes autonomously and in sufficient quantity for its needs starting from simpler products containing carbon (C), hydrogen (H), oxygen (O) and nitrogen (N).

Their integration must therefore be decided together with the attending physician and only in particular physiopathological conditions. To this group belong: serine, alanine, glutamic acid, aspartic acid and asparagine.

BCAAs: what branched chain amino acids are and how they work in our body

Branched chain amino acids are indicated with the acronym BCAA, English acronym for “Branched Chain Amino Acids”, or branched chain amino acids, and are represented by the 3 essential amino acids leucine, isoleucine and valine.

The human organism cannot produce them but must receive them through food. The name of BCAAs refers to their chemical structure, characterized by a branched side chain.

In Figure 1 the molecular structure of BCAA is represented.

Figure 1: Molecular structure of BCAAs in green, inside the red circle, the branched side chains are highlighted.

Over the past decade, the use of BCAA supplements has especially spread among bodybuilders and in extreme endurance sports such as marathon, cross country cycling, open water swimming, triathlon etc.

In fact, BCAAs possess some characteristics that differentiate them from all other amino acids. The first aspect concerns their absorption since they are captured directly by the muscles, without passing through the hepatic metabolism.

Within the muscle tissue, BCAAs are used by cells to rebuild proteins damaged by mechanical stresses given for example by intense physical exercises, allowing rapid fiber repair, with and fast recovery.

The second feature is that BCAAs are the major constituents of muscle tissue proteins: they represent 35% of the amino acids present in muscle and contribute about 15-25% of the total protein intake.

Until recently it was believed that the body used BCAAs as an energy reserve only in extreme cases of glucose and fatty acid deficiency.

However, recent studies have instead shown that these amino acids are used as fuel for energy production already at the beginning of intense aerobic exercise.

Leucine is the most important of the three BCAAs as it works as an anabolic (i.e. it stimulates the production of complex molecules starting from simple molecules) by increasing the concentration of growth hormone (or somatotropic) and accelerating protein synthesis.

Isoleucine and valine support muscle development by stimulating the insulin receptor in muscle cells and not in fat or liver cells.

Consequently, there is a high traffic of nutrients (BCAAs and sugars) towards the cells which allows muscle recovery and the restoration of glycogen reserves, used as fuel.

This process is very fast and starts in the first 40-50 minutes of training up to the next two hours.


Foods rich in branched chain amino acids and nutritional values

Branched chain amino acids are found in many protein-rich foods. However, lifestyle and nutrition can influence the correct intake of all the necessary substances and for this reason there are several amino acid and protein supplements on the market.

Taking BCAAs from protein foods is very beneficial as it provides all the essential amino acids and other nutrients. Lean meat, especially red meat, has a high BCAA content due to the higher amount of protein than the same meat with more fat.

For those who do not like red meat, a good source of amino acids is constituted by white meat of chicken and turkey but also fish such as salmon and tuna.

Eggs also have an excellent amino acid profile; in fact, egg white is the richest part in proteins, with a minimum intake of fats and carbohydrates.

Milk, with whey proteins and dairy products, is a complete food, with a high percentage of BCAAs and glutamine, ideal for athletes who practice endurance sports.

For those who follow a vegan or vegetarian diet it can be difficult to get the right amount not only of BCAAs but also of proteins and other essential amino acids; for this reason, a valid help is represented by plant-based food supplements and products based on soy, legumes, quinoa and dried fruit, with a good amino acid profile.

In Table 1 the main dietary sources of BCAA are listed.

Food Portion BCAA (grams)
Beef, round, roast 100 grams 6,8
Chicken breast 100 grams 5,88
Whey powder 1 full spoon 5,5
Powdered soy lecithin 1 full spoon 5,5
Canned tuna 80-100 grams 5,2
Salmon 100 grams 4,9
Turkey breast 100 grams 4,6
Grana cheese / Parmesan cheese 50 grams 4,5
Eggs 2 eggs 3,28
Beans and lentils 100 grams 2,5-3
Tofu and tempeh 84 grams 0,9-2,3
Whole milk 1 cup (about 235 mL) 2,2
Greek yogurt 140 grams 2
Pumpkin seeds, walnuts and hazelnuts 28 grams 1

Table 1: protein foods that provide BCAAs

Effects of BCAAs on health

BCAA supplements are best known among those who practice intense sporting activity however, they are also used in some pathological conditions to restore homeostasis in patients with liver disease or who have suffered muscle damage as a result of diseases or trauma such as untaps, strains or severe burns.

There are still few studies available to confirm these effects with certainty and further data are needed.

The benefits of taking BCAAs are listed below.

Reduction of physical and mental fatigue during training
Some research conducted on healthy volunteers who took BCAAs during physical activity found a reduction in both physical and mental fatigue of 15% compared to those who took the placebo.

Intake of BCAAs increased the fatigue resistance of 17%.

A further study conducted on a heat stress cycling test showed that cyclists who were asked to ingest a drink containing BCAAs cycled 12% more than the placebo group.

The use of BCAA supplements appears to improve breathing due to the 9% reduction in carbon dioxide (CO2) in the blood that normally increase with exercise, instead increasing the ventilatory response which allows the body to receive more oxygen at a higher speed.

However, BCAAs have no effect on heart rate and the increase that is found in the training phase is given by the presence in supplements of other stimulating substances such as caffeine.

Reduction of muscle pain after training
BCAAs work by lowering the blood levels of enzymes creatine kinase and lactate dehydrogenase, involved in muscle damage and the sensation of soreness (the "crazy meat").

According to research conducted on healthy volunteers, those who took BCAA supplements found 33% less muscle soreness after training than those who did not.

In some cases, those who took BCAAs and underwent an exercise test after 24-48 hours performed better than 20%.

However, the researchers point out that the observed results may also vary according to gender and the protein content resulting from the type of individual diet.

Increase in muscle mass
Many sportsmen, especially bodybuilders, purchase supplements to increase their muscle mass as the BCAAs activate the enzymes responsible for muscle development and building the proteins necessary for maintaining the structure and functionality of the muscles.

Some research has observed an increase in muscle mass in supplements that contain a higher percentage of leucine than isoleucine and valine as, as explained in the second paragraph, it has anabolic activity.

Weight control
Some clinical studies have found that consuming around 15 grams of BCAAs results in a lower 30% risk of developing overweight or obesity than low-protein diets.

Taking BCAA supplements is helpful in fat loss and weight control. A 19-day study of competitive wrestlers showed that the group taking BCAAs associated with a low-calorie but high-protein diet lost 3.5 kg more than the group given a soy protein supplement. .

The BCAA group also found a loss of 0.6% of fat more than the others, despite the type of diet followed by the two groups was the same.

Stimulation of the immune system
Taking BCAAs contributes to the recovery of white blood cells after intense training, essential for fighting infections and also stimulates the production of cytokines, molecules involved in the functioning of the immune system.

Maintenance of muscle mass in case of chronic diseases
BCAAs and in particular leucine, contribute to the maintenance of muscle mass of people suffering from chronic diseases that interfere with protein synthesis, with consequent loss of body proteins and muscle mass such as tumors but also eating disorders such as anorexia.

These supplements are administered intravenously to facilitate the recovery of people with severe injuries or burns who need to produce high amounts of protein to heal.

Reduction of complications related to liver failure
A possible brain complication of this condition is hepatic encephalopathy which can lead to confusion, loss of consciousness and even coma and death due to the liver being unable to remove toxins from the body.

A recent scientific journal suggests that supplementing BCAAs in patients with liver disease may be more beneficial than other supplements given to reduce the severity of encephalopathy.

However, administration of BCAAs did not improve the survival rate, nor did it unfortunately reduce the occurrence of other complications of liver disease such as infections and gastric bleeding.

According to a review of studies in patients undergoing liver surgery, BCAA-enriched intravenous solutions helped improve liver function and reduce the risk of postoperative complications and hospital stay times.

In subjects with liver disease, BCAA supplements have been found to be effective in decreasing fatigue and weakness along with muscle cramps, also improving the quality of sleep.

How much, when and for how long to take BCAAs

Intake of BCAAs depends on individual needs and goals and therefore there is no precise dosage.

According to the Ministry of Health, the optimal dosage for supplements should be 5 grams per day of BCAAs, enriched with vitamins B1 and B6, although experts recommend 1-2.5 grams per kg of body weight per day. .

Some studies have found that the best benefits in athletes are obtained with doses between 10 and 20 grams of branched chain amino acids per day.

In fact, during physical efforts or drastic diets, the body uses the protein reserve present in the muscles, consisting of BCAA for 35%.

This could cause damage or stress to the muscle mass while the intake of 5 grams of BCAAs immediately and quickly available has a preventive and protective action on the muscles.

Those who do 3 or more workouts a week should take BCAAs every day to support the body; doses of less than 5 grams recommended do not adequately compensate for muscle stress due to intense sport. In general, healthy and athletic adults should consume the following quantities:

  • Women: a minimum of 9 grams of BCAAs per day
  • Men: a minimum of 12 grams of BCAAs per day.

Those who have a high-protein diet and do not engage in professional endurance sports probably do not need BCAA supplements.

BCAAs act differently on the body based on the time of intake during training, according to the concept of nutrient timing.

In fact, taking supplements before training has a protective action, making the right amount of nutrients immediately available so that the muscle works at its best, without affecting its protein reserves.

This is recommended for modeling or cardio training, resistance training lasting 60 minutes or more, or for training in the morning on an empty stomach.

During training, BCAAs provide nourishment to the muscles under exertion by reducing the feeling of fatigue. The intake of BCAAs at the end of the workout stimulates the synthesis of new muscle proteins, allowing a rapid recovery; this is particularly suitable for bodybuilders and boxers who exert excessive effort and for endurance athletes to prevent and / or avoid post-workout muscle pain.

In Table 2 examples of programming and taking from all sources of BCAAs during training are shown, divided by gender, type of activity, methods and times of recruitment.

However, it should be noted that the long-term intake of high doses of BCAAs by professional athletes (especially bodybuilders) requires medical monitoring and the execution of tests such as bioimpedance measurement (BIA) to assess body composition (1TP1 , fat, intra- and extra-cellular water) and evaluation of renal function (creatinine clearance and glomerular filtration rate) as excess BCAA is eliminated in the urine.

Physical activity Women (50-55kg) Men (70-75kg)
Normal (gym, fitness, running ...) 1-2 times / week   5-9 g / day (0.1-0.18 g / kg lean mass / day) 1-2 intakes (before and after * work out) 12-20 g / day (0.17-0.28 g / kg lean mass / day) 1-2 intakes (before and after * work out)
Moderate / intense / competitive (gym, crossfit, running, cycling, amateur weightlifting ...) 3 or more / week Up to 12 g / day (0.24g / kg lean mass / day) 4-5 intakes (before and after * work out) 30-40 g / day (0.42-0.57 g / kg lean mass / day) 6-8 intakes (before and after * work out)
Bodybuilding, boxing, endurance professionals 35-40 g / day 6-8 intakes (before, during and after * work out) 35-40 g / day 6-8 intakes (before, during and after * work out)

Table 2: BCAA supplement intake scheme. * “after” means within 30-40 minutes (maximum 1 hour from the end of the workout to get more benefits).

Long-term intake of BCAAs is not a problem and, to obtain good results, experts recommend cycles of 30-40 days, which can be repeated as needed.

When BCAA supplements are used as a support for the treatment of certain diseases, the dosages change.

For example, in the case of hepatic encephalopathy the range goes from 16 to 25 grams of BCAAs per day for three months under close medical supervision; the dosages are also often divided into three administrations throughout the day.

Side effects

Taking BCAAs in the right dosages is safe and well tolerated by healthy individuals.

However, at high doses and with high-protein and high-calorie diets, some side effects may be encountered, including: fatigue, gastrointestinal disorders, hypertension and headache.

While properly taken BCAAs contribute to improved brain function, excessive dosage can negatively impact mood as high levels of BCAAs in the blood compete with the amino acid tryptophan for transport to the brain.

Tryptophan is the only precursor to the hormone serotonin, also called the hormone of happiness, which promotes good mood and sleep, as well as regulating appetite.

Excess BCAAs displace tryptophan, lowering the mood, with an increase in the sense of hunger.


There are also some conditions, listed below, for which the intake of BCAA supplements is contraindicated.

  • Amyotrophic Lateral Sclerosis (ALS): rare neurodegenerative disease that causes the loss of motor neurons that control movements and which leads in a short time to paralysis of voluntary muscles, including respiratory ones. Life expectancy is very short. Patients with ALS have high levels of BCAAs in their blood therefore, taking branched chain amino acid supplements would be deleterious. ALS is known to most as the disease of professional footballers (for example Stefano Borgonovo). According to a study conducted in 2010 and published in the Experimental Neurology journal by the University Tor Vergata of Rome and financed by the Ministry of Health and the Istituto Superiore di Sanità, the disproportionate and above all uncontrolled intake of multiple supplements, at excessive dosages and for too long periods in order to continuously improve competitive performance beyond the limits, can cause changes in nerve cells preparing (not causing!) the onset of the pathology. The causes of ALS are currently unknown as it is a multifactorial disease that does not only affect sportsmen. For those who practice sports and wish to take supplements, it is good to remember that it is counterproductive to take multiple products together or to rely on DIY for the doses; for a healthy athletic preparation and for your own health it is advisable to always be supported and advised by doctors and professionals and to use quality products.
  • Seizure Disorders: Taking BCAA supplements or a high-protein diet could increase the frequency of events in those suffering from seizures.
  • Maple Syrup Urine Disease: Also known as branched-chain ketoaciduria is a genetic metabolic disorder caused by the deficiency of an enzyme that processes BCAAs. Patients have high levels of BCAAs in their blood and urine, which smell and color resemble that of maple syrup.
  • Scheduled Surgery: Since BCAAs affect circulating glucose levels, it is advisable to stop taking supplements two weeks before surgery for proper glucose monitoring during and after surgery.
  • Chronic alcoholism: although BCAAs have a positive effect in liver diseases, they are to be avoided in alcoholics as they increase the likelihood of complications.
  • Pregnancy and breastfeeding: as there is not yet sufficient evidence on the safety of BCAAs in these stages of life, their intake is not recommended, even in women who play sports during pregnancy.


BCAAs decrease the absorption of the drug Levodopa, reducing the effectiveness of the therapy.

Levodopa is the precursor of the neurotransmitter dopamine and is used in the treatment of parkinsonism caused by Parkinson's disease, encephalitis or carbon monoxide and manganese poisoning.

It is therefore advisable to evaluate the intake of BCAA with your doctor and in any case to avoid concomitant intake with Levodopa.

Since BCAAs also lower blood sugar, special care should be taken while taking antidiabetic drugs to avoid causing excessive and dangerous hypoglycemia.

Taking corticosteroids and drugs for thyroid diseases, on the other hand, decreases the effect of BCAAs on the formation of new muscle proteins.


There are BCAA supplements on the market in tablets (or capsules) or powder.

The tablets are certainly the most practical format to take with you, however, the powder format, for the same weight, is more effective.

To get a quick and effective response from the body, you need 5 grams of BCAA powder, which is equivalent to about 10-15 capsules.

The powder formulations are also available in different flavors and allow them to be dissolved in water or soft drinks by making the action of the BCAAs coincide with the restoration of correct hydration and hydro-salt balance after training.

The supplements sold show different ratios between leucine, isoleucine and valine, for example: 2:1:1, 4:1:1; 8:1:1.

Leucine is always in greater quantities due to its biological importance in slowing down the oxidation of muscle proteins by promoting protein synthesis and recovery.

Leucine intervenes and is necessary for the synthesis of hemoglobin while the function of valine is to provide energy during prolonged efforts.

The 2: 1: 1 ratio is the classic one recommended before and after the work out, while the increased leucine ratios are mainly used in the recovery phases after training, especially in bodybuilding.

At our site you can buy BCAA supplements in tablets or powder in different ratios and enriched with vitamin B6 which contributes to the normal functioning of the energy metabolism, to the reduction of tiredness and fatigue, to the functioning of the nervous and immune system. In addition, you can purchase high-quality supplements with the KYOWA QUALITY® logo.

KYOWA QUALITY® brand products

KYOWA HAKKO BIO is a Japanese biochemical company, world leader in the biotechnology sector.

It has over 60 years of experience in chemical synthesis through innovative fermentation-based processes in order to produce useful substances such as amino acids, vitamins, nucleic acids, organic acids and proteins of pharmaceutical, health and food interest.

The production processes also have the aim of minimizing the environmental impact. The distinctive elements of the company are: quality of raw materials, scrupulous controls on production systems, numerous international quality certifications and quality controls on the finished product.

The company is also engaged in scientific research, quality management and constant education of staff and final consumers.

The amino acids with the KYOWA QUALITY® (KQ) logo have excellent stability and are free of chemical (heavy metals) and microbiological (endotoxin) contaminants, therefore they are defined as ultra pure.

These products comply with the requirements of the main pharmaceutical monographs such as: Japanese Pharmacopoeia (JP), Phramacopoeia of the United States of America (USP) is European Pharmacopoeia (EP).


  1. emanuele says:

    Si possono assumere bcaa dopo allenamento e anche le proteine in polvere ? Entrambi nell arco
    Di un’ora ?

    1. BiolineIntegratori says:

      Grazie per il suo quesito. Certo, considerando la modalità di utilizzo espressa sulle etichette dei nostri prodotti non esistono controindicazioni nell’assunzione contemporanea di BCAA e proteine nell’ora dopo l’allenamento. Considerato l’apporto di BCAA dalle proteine, consigliamo comunque di moderare l’assunzione di queste ultime (da 30 g consigliati a 20 g) se associate alla dose di 5 g di BCAA

  2. emanuele says:

    Si possono assumere bcaa e proteine subito
    Dopo L allenamento?

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