Have you ever wondered what amino acids are needed for in your body and how you can get them? You are probably also wondering what the symptoms of an isoleucine deficiency can be and what you can do about it.
We answer these and other questions in our big isoleucine test 2022. We explain what products are available on the market and what you have to look out for when buying them. We also give you important background information from current studies on the topic of isoleucine.
- 1 Weekly newsletter with the best personal finance tips
- 2 Summary
- 3 The best Isoleucine: Our Picks
- 4 Buying and evaluation criteria for isoleucine
- 5 Guide: Frequently asked questions about isoleucine answered in detail
- 5.1 What is isoleucine and what effect does it have?
- 5.2 What does isoleucine contain?
- 5.3 How much isoleucine is needed per day?
- 5.4 At what time should I take isoleucine?
- 5.5 What types of isoleucine are there?
- 5.6 How much does isoleucine cost?
- 5.7 How does an isoleucine deficiency develop and what are the symptoms?
- 5.8 What alternatives are there to isoleucine?
- 5.9 How is isoleucine produced?
- Together with other amino acids, isoleucine belongs to the essential proteinogenic amino acids. These are not produced by the body, but must be taken in through food or dietary supplements.
- Meat, dairy products or cereals are a natural source of isoleucine. If this is not enough, isoleucine is available in capsule, powder or liquid form. There is no exact amount, but a guideline is 20 mg of isoleucine per kilogram of body weight.
- Isoleucine is depleted during sport, but also through physical stress such as operations or illness. An isoleucine deficiency can cause symptoms such as muscle weakness, fatigue or listlessness.
The best Isoleucine: Our Picks
Buying and evaluation criteria for isoleucine
There are many different products that contain isoleucine. Based on our criteria, we would like to give you some tips so that you can buy the right product for you. You should consider the following points:
In the following sections, we have explained the individual criteria in more detail. These should help you find the right isoleucine product for you.
Quantity per pack
The quantity per pack is crucial. You should always calculate the price of the different products to one unit so that you can really compare the products.
For powders, you can calculate the price per portion. For drinks you should compare the price per litre, you can do the same for shots.
Of course, you always have to consider how often you want to take isoleucine. Depending on how often you want to consume isoleucine, it may be worthwhile to buy a smaller package so that you don't buy too much isoleucine or the product expires before you have used it all.
Animal or Vegan
Isoleucine is found in a variety of foods. Among others, in meat, dairy products and cereals. If you are vegetarian or even vegan, look for a vegan version. There is also synthetic isoleucine on the market.
However, you will not notice any difference in quality or effect. The products are always the same isoleucine. If you are not sure whether you want a vegan or animal product, you can simply ask for advice.
Depending on the type of product, the amount of isoleucine varies greatly. Often, only the total number of all amino acids contained is stated. First find out how much isoleucine you should take. This is often reflected in the price. Compare the amount of isoleucine per 100g on the package. This will help you choose the right product.
BCAA powders often contain the right ratio of essential amino acids. You can use the measuring spoon provided to determine the correct amount. In the case of capsules, it is indicated how many capsules you should take per day.
In any case, it is worth consulting your fitness coach. Otherwise, you may spend a lot of money on the products but not feel any effects due to incorrect use.
While the isoleucine capsules are tasteless, the powder or drinks come in various flavours. Drinks are available in orange, cherry or green tea-lemon flavours. With the powder, there is a much wider choice. In addition to the neutral variant, we have found flavours such as:
Depending on the manufacturer, the choice is larger or smaller. First decide on the product and only then on a flavour. Otherwise, your product may not come in the desired flavour and you may be disappointed.
|Capsules and tablets||Flavourless|
|Powders and drinks||Wide range of common and unusual flavours|
Which flavour you choose depends on your personal preference. Opt for a smaller pack at the beginning or ask your shop assistant if there is a possibility to try it.
When making your choice, also consider what other ingredients are included and how much. In particular, sugar and fat are important metrics if you are using the product during weight loss.
In addition, some products contain substances such as gelatine, which is made from animal connective tissue. They also contain colourings or other binding agents.
Guide: Frequently asked questions about isoleucine answered in detail
Below we have answered the most important questions about isoleucine. We have analysed and summarised various studies for you. You should then have a good basis for deciding whether or not to take isoleucine.
What is isoleucine and what effect does it have?
However, the body cannot produce it itself, but must absorb it through food or supplements. Isoleucine is an essential nutrient for humans, both for physiological and immune functions. Isoleucine also plays a role in the body's growth and protein metabolism, as well as in glucose transport.(1, 2, 3)
However, you will most often come across BCAAs in connection with sport. They are supposed to help build muscle, shorten the recovery time or prevent muscle loss during a diet. However, if you only focus on the intake of BCAAs or isoleucine in particular, the effects will not be as great. Other proteins and amino acids must also be consumed.(3, 4, 5)
But beware: Taking supplements such as BCAA powder with isoleucine, isoleucine drinks or shots do not replace a meal! They are supplements and not substitutes. This also applies to all other products such as protein powders or vitamin supplements.
What does isoleucine contain?
Likewise, isoleucine is found in grains such as wheat. So products like bread, pasta or corn are good sources. Isoleucine is also found in milk or dairy products.(2, 3)
How much isoleucine is needed per day?
The best way to determine the exact amount is to talk to your fitness coach or get advice from a pharmacy or your family doctor. Especially if you have a deficiency or are on a diet, it is worthwhile to determine the exact dosage.
At what time should I take isoleucine?
Again, it is worth consulting your fitness coach or a pharmacy staff member. Often, personal experience can also help you make your decision.
What types of isoleucine are there?
|Isoleucine capsules or tablets||Isoleucine with high purity. This prevents the absorption of other substances and allows the amount to be adjusted|
|BCAA powder||combination of all essential amino acids. Drink can be prepared by the user|
|BCAA Drink||Ready-to-use drink that can be easily transported|
|BCAA-Shot||Small amount, but highly dosed|
Which product you choose depends on the area of application.
How much does isoleucine cost?
|Isoleucine capsules||approx. 25 to 50 euros, depending on pack size|
|BCAA powder||approx. 10 to 50 euros, depending on pack size|
|BCAA drink||approx. 5 to 8 euros per litre|
|BCAA shot||approx. 1.50 to 3 euros per shot|
In any case, get advice from a specialist before buying so that you buy the right product for you. It is best to compare the price per kilogram for powder and the price per litre for drinks. For the shots, it is worth calculating the price per shot.
How does an isoleucine deficiency develop and what are the symptoms?
The body reacts to this with muscle weakness, listlessness and fatigue. But mental exhaustion is also a sign of isoleucine deficiency.(9, 10)
What alternatives are there to isoleucine?
How is isoleucine produced?
However, you don't have to worry about the manufacturing process when choosing your product. The end result is always the same and you will have isoleucine in your product.
Photo source: Dudzi?ski/ 123rf.com
Gu C, Mao X, Chen D, Yu B, Yang Q. Isoleucine Plays an Important Role for Maintaining Immune Function. Curr Protein Pept Sci. 2019;20(7):644-651. doi: 10.2174/1389203720666190305163135. PMID: 30843485.
Schütz L-M. (2020). Nahrungsergänzungsmittel im sportlichen Bereich: Verzweigtkettige Aminosäuren und ihr Einfluss auf die sportliche Leistungsfähigkeit. Hamburg: Diplomica Verlag. ISBN: 978-3-86341-622-5
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Brestenský, M., Nitrayová, S., Patráš, P., Heger, J., & Nitray, J. (2015). Branched chain amino acids and their importance in nutrition. Journal of Microbiology, Biotechnology and Food Sciences, 05(02), 197–202. https://doi.org/10.15414/jmbfs.2015.5.2.197-202
Blomstrand E, Hassmén P, Ek S, Ekblom B, Newsholme EA. Influence of ingesting a solution of branched-chain amino acids on perceived exertion during exercise. Acta Physiol Scand. 1997 Jan;159(1):41-9. doi: 10.1046/j.1365-201X.1997.547327000.x. PMID: 9124069.
Blomstrand E, Hassmén P, Ekblom B, Newsholme EA. Administration of branched-chain amino acids during sustained exercise--effects on performance and on plasma concentration of some amino acids. Eur J Appl Physiol Occup Physiol. 1991;63(2):83-8. doi: 10.1007/BF00235174. PMID: 1748109.
Hassmén P, Blomstrand E, Ekblom B, Newsholme EA. Branched-chain amino acid supplementation during 30-km competitive run: mood and cognitive performance. Nutrition. 1994 Sep-Oct;10(5):405-10. PMID: 7819652.
Arndt K, Albers, T. (2011) Handbuch Protein Und Aminosäuren: Optimaler Einsatz Von Protein & Aminos Im Sport, in Der Diät, Bei Erkrankungen, Zur Gesundheitsvorsorge : Beste Kombinationen Und Exakte Angaben Zu Dosierungen, Neben- Und Wechselwirkungen. 3. Aufl. Arnsberg: Novagenics
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Chibata I, Itoh T, Izumi Y. (1978). Production and Utilization of Amino Acids. Angewandte Chemie, Ausgabe(17), 176 - 183.
Ra SG, Miyazaki T, Kojima R, Komine S, Ishikura K, Kawanaka K, Honda A, Matsuzaki Y, Ohmori H. Effect of BCAA supplement timing on exercise-induced muscle soreness and damage: a pilot placebo-controlled double-blind study. J Sports Med Phys Fitness. 2018 Nov;58(11):1582-1591. doi: 10.23736/S0022-4707.17.07638-1. Epub 2017 Sep 22. PMID: 28944645.
Howatson G, Hoad M, Goodall S, Tallent J, Bell PG, French DN. Exercise-induced muscle damage is reduced in resistance-trained males by branched chain amino acids: a randomized, double-blind, placebo controlled study. J Int Soc Sports Nutr. 2012 Jul 12;9:20. doi: 10.1186/1550-2783-9-20. PMID: 22569039; PMCID: PMC3395580.