Anyone who has read up on sports supplements has probably come across ornithine. Ornithine is known as a supplement for increased performance. Often marketed as a combination product with L-arginine, ornithine is also attributed other effects outside of sports.
In our guide Ornithine Test 2022 we would like to support you in your decision to buy an ornithine preparation. We present important information about ornithine and the various effects it can have on the body.
- 1 Weekly newsletter with the best personal finance tips
- 2 Summary
- 3 The Best Ornithine: Our Picks
- 4 Buying and evaluation criteria for ornithine products
- 5 Guide: Frequently asked questions about ornithine products answered in detail
- Ornithine, or also known as L-ornithine, is a non-essential amino acid that is produced in sufficient quantities from L-arginine in the human body.
- Ornithine helps break down ammonia, can improve athletic performance, supports liver function and detoxification.
- There are two dosage forms of ornithine, powder and capsules, and it is mostly marketed as a dietary supplement for muscle building in sports.
The Best Ornithine: Our Picks
Buying and evaluation criteria for ornithine products
In the following section we would like to show you which criteria you can compare and evaluate ornithine preparations.
When buying ornithine, you can pay attention to various aspects, such as:
In the following, you can find out about the individual criteria and use this information for your decision.
Ornithine comes in two forms, powder and capsules. The mode of action is the same for both forms. The capsule form can be taken on the go, but the powder needs to be mixed with liquid, which can be difficult when travelling.
The ornithine powder is absorbed more quickly into the body, whereas the capsules still need to be dissolved in the stomach. With both forms, it is advisable to take the supplements with liquid. The decision between the powder or the capsules is up to your preference.
Ornithine in capsule form is available in active ingredient amounts between 400 and 600 milligrams. In the case of the powder, the dosage is up to you.
In addition to ornithine, the capsules also contain other additives that are harmless to the human body and have certain properties.
|Silicon dioxide||A release agent that absorbs water and prevents clumping|
|Microcrystalline cellulose||A release agent and filler|
|Magnesium salt||A release agent that prevents clumping|
|Titanium oxide and iron oxide||Colourants E171, E172, which provide brown colour|
|HPCM||Hydroxypropylmethylcellulose (HPMC), a soluble film coating that serves as a capsule shell|
The above additives have no negative effects on the body. All additives except magnesium salts are excreted by the body undigested.
Suitability for allergy sufferers
It is advisable to read the list of ingredients. Capsules can very often contain gluten and are therefore not suitable for allergy sufferers. People following an alternative diet should also read the list of ingredients. It can happen that capsules are processed with bovine gelatine and are therefore not suitable for vegetarians and vegans.
Ornithine capsules are also made with vegetable capsule shells. Fillers such as rice flour are also used to avoid gluten in the manufacturing process.
Ornithine is safe and well tolerated by most people at the recommended dosages. Ornithine is an amino acid that is produced in the body itself.
Unpleasantness could occur in the event of an overdose or an intolerance that may be triggered by the additives. Familiarise yourself with the ingredients listed on the product label. In the guide, we also have information about possible side effects.
Guide: Frequently asked questions about ornithine products answered in detail
In order to inform you comprehensively about the effectiveness of ornithine and to give you an understanding of the current state of science, we have summarised all the important information in the following sections.
What is ornithine?
In the body, ornithine plays an important role in the urea cycle through the formation of urea and thus makes an important contribution to the detoxification of the human body. Together, L-ornithine and L-arginine can release growth hormone, adrenaline and insulin, regulate cholesterol and blood pressure and promote protein build-up.
To further enhance detoxification of the body, for example if there is underlying liver disease or increased stress from physical activity, you can take ornithine as a supplement in capsule or powder form.
How does ornithine work?
Ammonia production in the muscles increases dramatically during intense exercise. The longer the workout, the higher the concentration of ammonia in the body and the more exhausted you become. Ornithine helps to reduce the accumulation of ammonia so that the intensity and duration of training can be maintained (11).
Several studies around athletic performance have produced positive results. However, larger studies are still needed to confirm its effectiveness.
Ornithine can help the body increase endurance and can speed up recovery after exercise.
In clinical studies, participants taking ornithine recovered faster from exertion and reported being less tired (11, 12, 13).
There are also studies that have seen only a slight improvement or no change in endurance or recovery (14, 15).
Liver function and detoxification
The liver is an important detoxification organ in the body. When the liver fails, all other organ systems are at risk, including the brain. Liver failure can affect cognition and muscle control. This condition is known as a liver-brain disorder (hepatic encephalopathy) (7).
In a few cases, supplementation of L-ornithine-L-aspartate (LOLA) has been able to prevent liver-brain disorder in chronic liver disease. These combination supplements reduced blood ammonia levels and improved cognitive symptoms (6, 7).
Supplementation with LOLA is also recommended for people with chronic liver disease who do not yet have cognitive symptoms (6, 7).
One study also looked at the efficacy in acute liver failure and could not see any improvement as ammonia had not been lowered(5).
Sleep and stress
Ornithine may reduce stress levels and improve sleep quality. An analysis of one study showed that in 52 stressed otherwise healthy adults, taking 400 mg of ornithine per day improved fatigue and sleep quality. Participants reported feeling less aggressive and more refreshed after a good night's sleep (4).
It was also found that cortisol levels had decreased significantly. Cortisol is a stress hormone that can cause stress-related diseases (3, 4).
In a study, researchers investigated the influence of ornithine on sleep-wake cycles in mice and results showed that ornithine could possibly be taken as a healthy food (1, 2).
In a study with mice, researchers increased the feeding of ornithine to see if wound healing could be accelerated with supplementation. Researchers administered ornithine enriched water and examined the healing of incisions in their skin after 14 days (8).
The wounds on the mice given ornithine healed faster than the wounds on the mice that ate a regular diet during the test (8).
Ornithine alpha-ketoglutarate (OKG) is formed from the amino acids ornithine and glutamine and is thought to promote muscle growth by encouraging the release of anabolic hormones in the body. This form of ornithine has been used in burn victims who have shown dramatic results around the healing process(9, 10).
When the human body heals a serious injury, it breaks down proteins to use them effectively and turn them into new tissue. Research has been done to see if ornithine alpha-ketoglutarate could prevent protein breakdown to speed up wound healing (9, 10).
Moderate alcohol consumption can have some positive aspects, but excessive alcohol consumption can undoubtedly be harmful to health. Simple and convenient methods that can help reduce the harmful effects of alcohol are being explored (17).
One study showed that taking 400 mg of ornithine after alcohol consumption reduced hangover symptoms and participants had improved recovery. They felt less tired, confused and aggressive in the morning. Further studies are needed to test the efficacy and quantity administration (17).
Where is ornithine found in food?
People who ate a diet high in grain proteins had higher levels of ornithine than people who ate mainly meat or dairy proteins (10).
Consuming foods containing arginine can also contribute to the production of ornithine. Ornithine is synthesised by arginine in the urea cycle. Poultry, fish, eggs, soybeans and quinoa contain all nine essential amino acids.
What are the possible side effects of ornithine?
The most common side effects are:
- Muscle cramps
In cases involving people who have the rare eye disease gyrate atrophy, long-term ornithine supplementation should be avoided as it can cause retinal damage (16).
Commercially available products contain a well-contracted amount, so overdose could not occur. When taking a powder, you should follow the instructions on the packet.
How much does ornithine cost?
In the following table you will find a list of the price ranges for the ornithine dosage forms that we have listed above.
|Ornithine powder||approx. 5-20 euros/100 grams|
|Ornithine capsules||approx. 7-27 euros/100 capsules|
In general, the price of ornithine ranges from about 10 to 50 euros. The decision depends on your personal preferences and how much you want to spend on a supplement.
What types of ornithine are there?
The following table provides a brief overview of the types:
|Ornithine powder||The intake is individually dosed by taking the powder with sufficient liquid such as water or fruit juice.|
|Ornithine capsules||Pre-dosed amount to be taken with some liquid.|
Both types have advantages and disadvantages. Your personal preference and the following sections can help you make a purchase decision.
Ornithine powder is usually preferred when looking for a quality pure product. Due to its pure form, allergy sufferers and people with different diets such as vegans can take the product safely. The body can also absorb the ornithine powder faster than in the capsule form.
The powder can be a little laborious as you have to dose it yourself, but it can be added to juices or shakes.
Ornithine capsules can be easy to take. The capsules are pre-dosed to the recommended amount and can be taken practically anywhere.
Ornithine powder is recommended as an alternative for people who find it difficult to swallow.
How should ornithine be dosed?
The following table shows various dosage recommendations that have been studied in clinical trials:
|Intended effect||Recommended dose|
|Athletic recovery||2g/day (11)|
|Athletic endurance||2g/day (13)|
|Sleep quality||400mg/day (4)|
|Hangover control||400mg/day (17)|
Higher dosages may cause side effects such as nausea and diarrhoea. To influence sleep patterns, ornithine should be taken at night before bed.
What are the alternatives to ornithine?
Preparations such as L-ornithine L-aspartate (LOLA), which can support liver function, and ornithine alpha-ketoglutarate (OKG), which has shown very positive results in burn victims(6, 9, 10).
A popular combination supplement is L-arginine and L-ornithine. Ornithine also works without arginine, but the combination showed that it could enhance muscle building.
Image source: Chander R / unsplash
Horiuchi M, Kanesada H, Miyata T, Watanabe K, Nishimura A, Kokubo T, Kirisako T. Ornithine ingestion improved sleep disturbances but was not associated with correction of blood tryptophan ratio in Japanese Antarctica expedition members during summer. Nutr Res. 2013 Jul;33(7):557-64. doi: 10.1016/j.nutres.2013.05.001. Epub 2013 Jun 12. PMID: 23827130.
Fukuda T, Haraguchi A, Kuwahara M, Nakamura K, Hamaguchi Y, Ikeda Y, Ishida Y, Wang G, Shirakawa C, Tanihata Y, Ohara K, Shibata S. l-Ornithine affects peripheral clock gene expression in mice. Sci Rep. 2016 Oct 5;6:34665. doi: 10.1038/srep34665. PMID: 27703199; PMCID: PMC5050418.
Davidson JR, Moldofsky H, Lue FA. Growth hormone and cortisol secretion in relation to sleep and wakefulness. J Psychiatry Neurosci. 1991 Jul;16(2):96-102. PMID: 1911740; PMCID: PMC1188300.
Miyake, M., Kirisako, T., Kokubo, T. et al. Randomised controlled trial of the effects of L-ornithine on stress markers and sleep quality in healthy workers. Nutr J 13, 53 (2014).
Acharya SK, Bhatia V, Sreenivas V, Khanal S, Panda SK. Efficacy of L-ornithine L-aspartate in acute liver failure: a double-blind, randomized, placebo-controlled study. Gastroenterology. 2009 Jun;136(7):2159-68. doi: 10.1053/j.gastro.2009.02.050. PMID: 19505424.
Stauch S, Kircheis G, Adler G, Beckh K, Ditschuneit H, Görtelmeyer R, Hendricks R, Heuser A, Karoff C, Malfertheiner P, Mayer D, Rösch W, Steffens J. Oral L-ornithine-L-aspartate therapy of chronic hepatic encephalopathy: results of a placebo-controlled double-blind study. J Hepatol. 1998 May;28(5):856-64. doi: 10.1016/s0168-8278(98)80237-7. PMID: 9625322.
Waghray A, Waghray N, Mullen K. Management of covert hepatic encephalopathy. J Clin Exp Hepatol. 2015 Mar;5(Suppl 1):S75-81. doi: 10.1016/j.jceh.2014.02.007. Epub 2014 Apr 1. PMID: 26041963; PMCID: PMC4442854.
Shi HP, Fishel RS, Efron DT, Williams JZ, Fishel MH, Barbul A. Effect of supplemental ornithine on wound healing. J Surg Res. 2002 Aug;106(2):299-302. doi: 10.1006/jsre.2002.6471. PMID: 12175982.
De Bandt JP, Coudray-Lucas C, Lioret N, Lim SK, Saizy R, Giboudeau J, Cynober L. A randomized controlled trial of the influence of the mode of enteral ornithine alpha-ketoglutarate administration in burn patients. J Nutr. 1998 Mar;128(3):563-9. doi: 10.1093/jn/128.3.563. PMID: 9482764.
Coudray-Lucas C, Le Bever H, Cynober L, De Bandt JP, Carsin H. Ornithine alpha-ketoglutarate improves wound healing in severe burn patients: a prospective randomized double-blind trial versus isonitrogenous controls. Crit Care Med. 2000 Jun;28(6):1772-6. doi: 10.1097/00003246-200006000-00012. PMID: 10890617.
Sugino T, Shirai T, Kajimoto Y, Kajimoto O. L-ornithine supplementation attenuates physical fatigue in healthy volunteers by modulating lipid and amino acid metabolism. Nutr Res. 2008 Nov;28(11):738-43. doi: 10.1016/j.nutres.2008.08.008. PMID: 19083482.
Zajac A, Poprzecki S, Zebrowska A, Chalimoniuk M, Langfort J. Arginine and ornithine supplementation increases growth hormone and insulin-like growth factor-1 serum levels after heavy-resistance exercise in strength-trained athletes. J Strength Cond Res. 2010 Apr;24(4):1082-90. doi: 10.1519/JSC.0b013e3181d321ff. PMID: 20300016.
Elam RP, Hardin DH, Sutton RA, Hagen L. Effects of arginine and ornithine on strength, lean body mass and urinary hydroxyproline in adult males. The Journal of Sports Medicine and Physical Fitness. 1989 Mar;29(1):52-56.
Demura S, Yamada T, Yamaji S, Komatsu M, Morishita K. The effect of L-ornithine hydrochloride ingestion on performance during incremental exhaustive ergometer bicycle exercise and ammonia metabolism during and after exercise. Eur J Clin Nutr. 2010 Oct;64(10):1166-71. doi: 10.1038/ejcn.2010.149. Epub 2010 Aug 18. PMID: 20717126.
Mikulski T, Dabrowski J, Hilgier W, Ziemba A, Krzeminski K. Effects of supplementation with branched chain amino acids and ornithine aspartate on plasma ammonia and central fatigue during exercise in healthy men. Folia Neuropathol. 2015;53(4):377-86. doi: 10.5114/fn.2015.56552. PMID: 26785372.
Hayasaka, S., Kodama, T., & Ohira, A. (2011). Retinal risks of high-dose ornithine supplements: A review. British Journal of Nutrition, 106(6), 801-811. doi:10.1017/S0007114511003291
Kokubo, T., Ikeshima, E., Kirisako, T. et al. A randomized, double-masked, placebo-controlled crossover trial on the effects of L-ornithine on salivary cortisol and feelings of fatigue of flushers the morning after alcohol consumption. BioPsychoSocial Med 7, 6 (2013).