20% off £30

Code:QUICK
Offers3 for 2 Mix & MatchSave up to 1/2 PriceOnline OnlyBuy one get one 1/2 priceBuy 1 Get 1 FreeOutlet2 For £5 Mix & MatchIntroductory Offer2 For £60 Mix & MatchShort Dated May 2025Vitamins & SupplementsVitamins & Supplements Shop AllHair, Skin & NailsCollagen & SilicaMuscle Support & Joint PainDigestive HealthMagnesiumFunctional MushroomsVitaminsShop all VitaminsMultivitaminsVitamin AVitamin BVitamin CVitamin DVitamin EVitamin KVitamin DrinksMineralsShop all MineralsMagnesiumIronZincCalciumSeleniumChromiumSupplementsShop all SupplementsFibre SupplementsAcidophilus & Friendly BacteriaPeppermint OilGrapeseed ExtractLecithinCollagen & SilicaOmega & Fish OilsPlant Sourced SupplementsSuperfood SupplementsArnicaApple CiderRaspberry KetonesAloe VeraChondroitin & MSMCo Enzyme Q10Evening Primrose OilGarlicGinkgo BilobaGlucosamineGlucomannanSeaweed, Kelps and Aquaceuticals5 HTPDigestive EnzymesSaw palmettoCharcoalConditionShop all ConditionCholesterolAllergy & Hay Fever CareAnxiety SupportBone & Muscle HealthMuscle Support & Joint PainBrain & Memory SupportWomen's HealthMen's HealthChildren's HealthCold & Immune SupportFatigueDigestive HealthHair, Skin & NailsHeart & CirculationLiver CareMood SupportSexual HealthSleep & RelaxationStress ReliefVisionWomen's HealthShop all Women's HealthPerimenopauseMenopauseMenstrual SupportUrinary Tract HealthPregnancy & ConceptionMen's HealthShop all Men's HealthProstate HealthChildren's HealthCBD Vitamins & SupplementsShop all CBD Vitamins & SupplementsCBD OilCBD CapsulesCBD SprayCBD GummiesHerbal & Licensed RemediesShop all Herbal & Licensed RemediesRescue RemedyAshwagandhaMilk ThistleGinseng & GuaranaHomeopathic & Flower RemediesShop all Homeopathic & Flower RemediesRescue RemedyTissue SaltsFlower RemediesHomeopathic RemediesAt-Home TestsVegan Vitamins & SupplementsHolland & BarrettVitabioticsSolgarNew NordicWeledaBioglanGrass & Co.Natures AidNature's WayNovomins3 for 2 Mix & MatchSave up to 1/2 PriceOnline OnlyBuy 1 Get 1 FreeOutletBuy one get one 1/2 priceShort Dated May 2025Dairy FreeGluten FreeSesame Seed FreeCelery FreeCereal FreeCrustaceans FreeEgg FreeFish FreeKiwi FreeLupin FreeNew inFood & DrinkFood & Drink Shop AllVegan Food & DrinkShop all Vegan Food & DrinkMeat-Free AlternativesDairy Free DrinksEgg SubstitutesVegan ProteinVegan Protein BarsDried Fruit, Nuts & SeedsShop all Dried Fruit, Nuts & SeedsDried FruitNutsSeedsMixesChocolate CoatedManuka HoneyTeas, Coffee & Hot BeveragesShop all Teas, Coffee & Hot BeveragesCoffee & Coffee SubstitutesMushroom DrinksHot ChocolateTeasSuperfood TeasMatcha & Green TeaHerbal TeaPeppermint TeaSleep & RelaxationSlimming TeaWomen's Health TeasDrinks & JuicesShop all Drinks & JuicesMultipack DrinksJuices & Health ShotsNatural Energy DrinksCoconut WaterKombuchaCBD DrinksSoft DrinksWaterAlcohol Free DrinksProtein ShakesSuperfoodsShop all SuperfoodsSuperfood BlendsSupergreensMoringa PowderSpirulinaMaca PowderFlaxseedBaobabChia SeedsGoji BerriesGut HealthHealthier SnackingShop all Healthier SnackingSweet SnacksSavoury SnacksLow Calorie SnacksChocolateCrisps & ChipsCrackers & CrispbreadsBiscuits & CookiesSnack BarsFlapjacksLiquoricePopcornSweets & MintsChocolate Coated SnacksFood CupboardShop all Food CupboardApple Cider VinegarCondiments & SaucesMeat-Free AlternativesSoup & Ready MealsRice, Pasta, Pulses & GrainsGravy, Broths & StockHoney, Jams & SpreadsShop all Honey, Jams & SpreadsManuka HoneyHoneyNut ButtersJams & ChutneysSyrupsSpreadsPateBreakfast CerealsShop all Breakfast CerealsCereals, Bran & FlakesGranolaMuesliOats & PorridgeBreakfast BarsCookingShop all CookingCooking IngredientsApple Cider VinegarCondiments & SaucesMeat-Free AlternativesSoup & Ready MealsRice, Pasta, Pulses & GrainsTinned FoodsHerbs, Spices & SeasoningGravy, Broths & StockHome BakingShop all Home BakingBaking IngredientsBaking MixesBreadFlourSweeteners & Sugar AlternativesEgg SubstitutesDairy Free DrinksShop all Dairy Free DrinksOat, Rice & Hemp DrinksSoya DrinksNut DrinksCoconut DrinksDesserts & CreamsNutritionally Complete FoodCoconutHolland & BarrettNaturyaGrenadePukkaTwiningsHeath & HeatherNakdManuka DoctorPerfectTedMeridianSave up to 1/2 Price3 for 2 Mix & MatchOnline OnlyBuy one get one 1/2 price2 For £5 Mix & MatchBuy 1 Get 1 FreeOutletShort Dated May 2025Gluten FreeDairy FreeWheat FreeSugar FreeEgg FreeMilk FreeSoya FreeNut FreeSesame Seed FreeCelery FreeNew inSports NutritionSports Nutrition Shop AllProteinShop all ProteinWhey ProteinClear ProteinMass GainersVegan ProteinDiet ProteinCaseinSports SupplementsShop all Sports SupplementsTestosteroneElectrolytesEnergy GelsSports CollagenCreatineShop all CreatineCreatine PowderCreatine CapsulesBars, Drinks & SnacksShop all Bars, Drinks & SnacksEnergy BarsProtein BarsProtein ShakesProtein SnacksNutritionally Complete FoodMeal Replacement ShakesPre Workout & EnergyShop all Pre Workout & EnergyPre WorkoutCaffeine Free Pre WorkoutAmino Energy PowdersIntra WorkoutPost WorkoutKetoAmino AcidsShop all Amino AcidsAmino Energy PowdersBCAAL-LysineGlutamineCarnitineArginineVegan Sports NutritionShop all Vegan Sports NutritionVegan ProteinVegan Protein BarsVegan Pre Workout & EnergyVegan Amino AcidsVegan CreatineSports AccessoriesShop all Sports AccessoriesBottles & ShakersFitness EquipmentApplied NutritionOptimum NutritionPrecision EngineeredUSNMyproteinGrenadeHuelPhDTriActiveSiSSave up to 1/2 Price3 for 2 Mix & MatchOutlet2 For £60 Mix & MatchBuy one get one 1/2 priceOnline OnlyBuy 1 Get 1 FreeIntroductory OfferGluten FreeDairy FreeSugar FreePalm Oil FreeSoya FreeCelery FreeCereal FreeCrustaceans FreeEgg FreeFish FreeNew inBeautyNatural Beauty Shop AllSkincareShop all SkincarePremium SkincareFace CareBody CareSun CareTanning & BronzingEye CareLip CareFoot CareHand & Nail CareSkin AilmentsSkin OilsCBD BeautyFace CareShop all Face CareCleanser & TonerFace MoisturiserFace Oil & SerumFace WashFace Exfoliators & ScrubsFace MasksHair CareShop all Hair CareShampoo & ConditionerHair ColouringHair MasksHair Oil & SerumHair Spray, Gel & MousseHair AccessoriesWashing & BathingShop all Washing & BathingShampoo & ConditionerBathing AccessoriesFeminine CareShower Gel & Body WashDeodorantDentalHand WashSoapBath Soak & OilBody ScrubBath Bombs & SaltsIncontinence SupportAromatherapy & HomeShop all Aromatherapy & HomePure Essential OilsBlended Essential OilsBase & Carrier OilsHolisticMother & BabyShop all Mother & BabyBaby Skincare & ToiletriesElectrical WellnessDr OrganicFaith in NatureWeledaNaturtintTisserandMiaromaSukinQ+ATrilogyChilds FarmSave up to 1/2 PriceBuy one get one 1/2 priceBuy 1 Get 1 FreeOnline Only3 for 2 Mix & MatchOutletIntroductory OfferShort Dated May 2025Alcohol FreeParfum FreeFluoride freePalm Oil FreeGluten FreeCelery FreeCereal FreeCrustaceans FreeDairy FreeEgg FreeNew inWeight ManagementWeight Management Shop AllFat Burners, Binders & Appetite SuppressantsShop all Fat Burners, Binders & Appetite SuppressantsFat BurnersFat BindersAppetite SuppressantsSlimming TabletsWeight Management Shakes Shop all Weight Management Shakes Meal Replacement ShakesDiet ProteinDiet Food & DrinkShop all Diet Food & DrinkSlimming TeasHealthier CookingLow Calorie SnacksFruit, Nuts & SeedsJuices & Health ShotsApple Cider VinegarExercise SupportShop all Exercise SupportFitness EquipmentMeal Replacement ShakesDiet ProteinProtein BarsHolland & BarrettUSNTREKEat WaterFrejaIdeal HealthNudie SnacksBraggGrenadeNatures AidSave up to 1/2 Price3 for 2 Mix & MatchOnline OnlyBuy one get one 1/2 price2 For £12 Mix & MatchBuy 1 Get 1 FreeGluten FreeSugar FreeWheat FreeDairy FreeCelery FreeCrustaceans FreeEgg FreeFish FreeKiwi FreeLupin FreeNew inHealth & WellnessShop all Health & WellnessBrain HealthEnergyJoints, Bones, & MusclesGut HealthSleep & RelaxationHolland & BarrettDr OrganicVitabioticsFaith in NatureOptimum NutritionWeledaNaturtintPrecision EngineeredApplied NutritionUSN3 for 2 Mix & MatchSave up to 1/2 PriceOnline OnlyBuy one get one 1/2 priceBuy 1 Get 1 FreeOutlet2 For £60 Mix & MatchShort Dated May 2025Gluten FreeDairy FreeAlcohol FreeSugar FreeWheat FreeEgg FreeSoya FreeSesame Seed FreeCelery FreeCrustaceans FreeNew inNew InBest SellersTrendingThe best of Holland & BarrettMedicines and HealthcareShop all Medicines and HealthcareHayfever & Allergy RemediesPain ReliefCough, Colds & Sore ThroatAntacids & GastrointestinalInfant & BabiesFemale HealthHaemorrhoids & Piles TreatmentsEar Care & Eye HealthFoot Care & Health Skin & ScalpMouth & Oral CareHair & ScalpTravelCareNurofenE45OilatumStrepsilsTiger BalmAnadinAnusolBeechamsBenylinBuy one get one 1/2 price3 for 2 Mix & MatchSave up to 1/2 PriceSave up to 1/2 priceNew inVeganShop for your WellnessGut HealthImmunityEnergySkincareWomen's HealthMenstrual HealthMenopauseJoints, Bones & MusclesHair, Skin & NailsSleep & RelaxationFood & DietChildren's HealthStress ReliefHealthy HeartLow Mood & DepressionConcentration & AlertnessEye HealthSexual HealthLearn about WellnessJoints, Bones & MusclesEnergyWomen's HealthPeriods & Cycle HealthMenopauseImmunityGut HealthFood & DietSports & FitnessSleep & RelaxationHair Skin & NailsArticlesAll articlesHealthFood & nutritionGut healthImmunityJoints, bones & musclesWomen's healthWellnessHair & skinMental wellbeingSeasonalSleep & relaxationSports nutritionRecipesAll recipesGluten freeLow sugarVeganDairy freePodcast
Skip to content

Your guide to essential amino acids

medico-author

Written byMedico Digital

sam-ward

Reviewed bySam Ward

Email
Facebook
Email
Facebook
Protein amino acids on a grey background with black dumbells.
Amino acids: tiny nutrients with big benefits. From muscle power to energy boosts, find out how these building blocks fuel your body – and the best foods to get them from

Summary

1What are amino acids?

Your body needs 20 different amino acids to function properly. Nine of these amino acids can’t be made by your body…

2Types of essential amino acids

You now know the basics about amino acids and their role in your body, but exactly which amino acids are classed as essential…

3Possible benefits of essential amino acids

Essential amino acids offer a range of possible benefits for your health and wellbeing – though it’s worth noting that more research is needed…

Explore related topics

You may have heard of amino acids before, but how much do you really know about them? 

Amino acids are the building blocks of proteins that your body needs to function correctly.

Keep reading to find out more about what amino acids do, why your body needs them and where you can find them.

What are amino acids?

Your body needs 20 different amino acids to function properly.2 Nine of these amino acids can’t be made by your body and must be consumed through your diet. These are known as ‘essential’ amino acids.2 Your body can produce the remaining 11, so getting them through your diet is less important. 

The main function of amino acids is to act as building blocks for proteins.1 Amino acids join together to form the proteins that your body needs to perform a range of functions, including building and repairing bones and muscles, making hormones and enzymes and supporting your immune system.

While your body doesn’t use protein as its preferred energy source, if you aren’t eating enough carbohydrates or if you’re in a large calorie deficit with inadequate fat stores, protein will get broken down and used to create energy.3

Types of essential amino acids

You now know the basics about amino acids and their role in your body, but exactly which amino acids are classed as essential? The list includes: 2 
  • methionine 
  • phenylalanine 
  • threonine 
  • tryptophan 
  • histidine 
  • lysine 
  • valine 
  • leucine 
  • isoleucine 
You may have also heard of branched chain amino acids (BCAAs). These essential nutrients include three of the above amino acids – valine, leucine and isoleucine – which are particularly well-known for their proposed benefits for exercise performance and recovery.4,5 This is because they can be used directly as fuel by the muscles, particularly when glycogen is depleted.

Possible benefits of essential amino acids

Essential amino acids offer a range of possible benefits for your health and wellbeing – though it’s worth noting that more research is needed to really dig into these potential perks. Below are some key areas where essential amino acids may offer a helping hand.

May provide your body with energy

Some research suggests that essential amino acids can positively affect energy balance. This could be particularly beneficial for athletes and people who do a lot of exercise, as the additional energy may help them push their bodies harder and/or for longer.4,5
 

May improve muscle function

Essential amino acids are thought to play a key role in muscle health, providing your body with the protein needed to build muscle mass and help your muscles recover following a workout. This could mean less muscle soreness and a faster return to exercise.4,5
 

May help with a better sleep/wake cycle

Sleep plays a crucial role in your overall health and wellbeing. When you’re asleep, your body and brain repair themselves and undergo various maintenance processes that prepare you to function the next day.7 This process is set by your circadian rhythm – AKA your internal body clock. Dive into our article on the circadian rhythm for everything you need to know. 

One study found that a sufficient amount of amino acids may help boost sleep quality – though much more research is needed to confirm this.8
 

Foods high in essential amino acids

Most people get the nutrition they need to support their health through their food. As you now know, your body can’t make essential amino acids by itself. This means that for optimal health, you need to consume foods that have essential amino acids in them.

Foods that contain all nine essential amino acids are called ‘complete proteins’. These include:
  • beef
  • poultry 
  • fish 
  • eggs 
  • dairy 
  • soy 
  • quinoa 
  • buckwheat 
Nevertheless, if you don’t like foods that are high in amino acids, you may want to consider amino acid supplements to ensure you’re getting your recommended daily amounts.

Exactly how much of each amino acid you need will vary depending on your goals, and of course, your own health. We recommend you always speak to your doctor before starting to take any supplement. 

Supplements are available in many different forms, including BCAA powders, and flavours to make them interesting and tasty.

Side effects of essential amino acids

Most people don’t experience any side effects when taking essential amino acid supplements. However, supplements can cause stomach upset in those with sensitivities.10 Other reported side effects include water retention and muscle cramps.10 

Currently, there’s no research on taking essential amino acid or BCAA supplements when pregnant and/or breastfeeding. So, if you’re pregnant, trying to conceive or currently breastfeeding, you should seek professional advice before taking any essential amino acid supplements.

The final say

Amino acids are thought to play important roles in your overall health and wellbeing, especially if you’re very active. 

Getting essential amino acids through a healthy and balanced diet is ideal, but supplements provide an effective alternative way of getting enough amino acids to optimise your health.

Disclaimer

This article provides informational advice and is not a substitute for medical care. Curated by experts for accuracy, we take great care to ensure the information is up-to-date and relevant. However, you should always consult your GP or healthcare professional before using supplements or alternative products, particularly if you have medical conditions or are under supervision.
 

Sources

  1. Allowances, National Research Council (US) Subcommittee on the Tenth Edition of the Recommended Dietary. Protein and Amino Acids. Recommended Dietary Allowances: 10th Edition. Washington (DC): National Academies Press (US); 1989. Available from: https://www.ncbi.nlm.nih.gov/books/NBK234922/ 
  2. British Nutrition Foundation. Protein [Internet]. [cited 2024 Jul 2]. Available from: https://www.nutrition.org.uk/nutritional-information/protein/ 
  3. Evans M, et al. Metabolism of ketone bodies during exercise and training: Physiological basis for exogenous supplementation. J Physiol. 2017;595(9):2857–71. https://doi.org/10.1113/JP273185 
  4. Martinho DV, et al. Oral Branched-Chain Amino Acids Supplementation in Athletes: A Systematic Review. Nutrients. 2022;14(19):4002. https://pubmed.ncbi.nlm.nih.gov/36235655 
  5. Salem A, et al. Branched-Chain Amino Acids Supplementation and Post-Exercise Recovery: An Overview of Systematic Reviews. J Am Nutr Assoc. 2024;43(4):384-396. https://pubmed.ncbi.nlm.nih.gov/38241335/ 
  6. NHS. Better Health: Sleep problems [Internet]. [cited 2024 Jul 2]. Available from: https://www.nhs.uk/every-mind-matters/mental-health-issues/sleep/ 
  7. Sejbuk M, et al. Sleep quality: A narrative review on nutrition, stimulants, and physical activity as important factors. Nutrients. 2022;14(9):1912. https://doi.org/10.3390/nu14091912 
  8. Elango R. Tolerable upper intake level for individual amino acids in humans: A narrative review of recent clinical studies. Adv Nutr. 2023;14(4):885–94. https://doi.org/10.1016/j.advnut.2023.04.004 
  9. Holeček M. Side effects of amino acid supplements. Physiol Res. 2022;71(1):29–45. https://doi.org/10.33549/physiolres.934790
 

Related Articles

Sign up for exclusive offers
Plus, get expert advice to support your health & wellness straight to your inbox when you sign up to Holland & Barrett emails.