Last updated: August 24, 2021

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L-methionine is a sulphur-containing and essential amino acid that can be taken in via food or food supplements. Since the amino acid is used as a therapeutic agent for many clinical pictures, it can be considered as medicine on the one hand, and on the other hand it finds popular use as a supplement for athletes.

Welcome to our L-methionine test 2021. We will provide you with important information about the different types of L-methionine and the factors you should consider before buying. With the help of our test article, you should be able to find the right L-methionine supplement for you.




Summary

  • Along with cysteine, L-methionine is one of the sulphur-containing essential amino acids in our body. Methionine is the precursor of the amino acids cysteine, taurine and the antioxidant glutathione. The key product of L-methionine is S-adenosylmethionine (SAM), which is involved in many metabolic processes. Thus, L-methionine participates in the synthesis of adrenaline, carnitine, creatine and melatonin
  • The sulphur-containing amino acid plays an important role in the synthesis of proteins and hormones. As a so-called start amino acid, it is at the beginning of a protein sequence, which can be followed by others
  • The current research on L-methionine is not yet complete, which is why it may provide helpful services in the future for other clinical pictures.

The Best L-Methionine: Our Picks

Guide: Questions you should ask yourself before buying L-methionine

What is L-methionine?

L-methionine is an essential sulphur-containing α-amino acid that, along with cysteine, is an important source of organically bound sulphur. Essential amino acids cannot be produced by the body itself. Therefore, the need for L-methionine is mainly covered by food.

Chemically, there are two forms of methionine. The D-form and the L-form, i.e. L-methionine. D-methionine is of little medical importance, so you can be sure that when methionine is mentioned, L-methionine is generally meant.

As a "start amino acid" to which other amino acids attach to form a protein, it plays an important role in building muscles. The proteinogenic amino acid is also the precursor of the amino acids taurine and cysteine and the antioxidant glutathione.

L-Methionin-1

L-methionine is important for building muscles and is therefore found in the supplements of athletes from a wide range of disciplines.
(Image source: unsplash/John Arans)

The body can produce important hormones, proteins and nucleic acids from L-methionine. Since it is involved in the synthesis of carnitine, adrenaline, melatonin and S-adenosylmethionine, it indirectly takes over many important functions in the organism.

S-adenosylmethionine (SAM), for example, is a key product of methionine, which plays an active role in many metabolic processes. SAM, in turn, is involved in the formation of new liver cells and promotes the transport of nerve messengers that are involved in depression.

Overall, methionine plays an important role in the series of essential amino acids because it provides sulphur and methyl groups that the body cannot produce itself, but which are needed to maintain important functions.

How does L-methionine work?

The sulphur in L-methionine has many positive effects on the body, but you should always discuss taking it for therapeutic purposes with your doctor. For example, the sulphur-containing amino acid can extract heavy metals such as mercury and arsenic, so that the liver is detoxified. (1)

The following are some of the proven effects of taking L-methionine:

  • Help with recurrent urinary tract infections (2)
  • Improving the absorption capacity of antibiotics (3)
  • Prevents the formation of urinary and kidney stones (4)
  • Protection against cell damage (5) (6)
  • Help with hair loss and brittle nails (7)

Help with recurrent urinary tract infections

Taking L-methionine can lead to relief of symptoms in recurrent urinary tract infections. The sulphur it contains causes the urine to become over-acidic, which is said to make certain pathogenic strains of bacteria such as E. coli no longer able to survive. These can no longer settle on the mucous membranes of the urinary tract and are simply flushed out. (2)

Prophylactic intake of L-methionine can prove to be an effective remedy against recurrent urinary tract infections. Especially in connection with the supportive administration of cranberry dragées, positive results have been observed in acute infections of the urinary tract.

Despite the fact that methionine lowers the ph-value of the urine, there are quite a few studies that do not confirm the effect of L-methionine in urinary tract infections. Therefore, we always recommend consulting a doctor or pharmacist in addition.

The absorption capacity of certain antibiotics can be improved

The mode of action of certain antibiotics that are used in the acidic range (ph value of 4 to 6) is increased by acidification of the urinary environment. For example, ampicillin, nalidixic acid and carbenicillin are among the antibiotics whose effectiveness can be increased by simultaneous intake of L-methionine. (3)

The amount of the sulphur-containing amino acid that should be administered in combination with antibiotics in order to achieve positive health effects is best discussed with your attending physician.

Prevents the formation of urinary stones and kidney stones

Since urinary and kidney stones are made of phosphates, they can dissolve in an acidic environment. The formation of new struvite stones (ammonium magnesium phosphate stones) and calcium phosphate stones, which are the result of urinary tract infections, is significantly and demonstrably reduced by L-methionine. (4)

Despite the isolated study successes, L-methionine should only be taken after consultation with a doctor.

Protects cells from damage

Since L-methionine is associated with the synthesis of gluthation, it can reduce oxidative stress. Indirectly, it causes an increase in life expectancy. Therefore, it is traded in medicine as an anti-aging agent. (5) and (6)

Helps with hair loss and brittle nails because sulphur strengthens the structure

Methionine and cysteine are building blocks of keratin, which in turn is an important building block of hair, nails and skin. If there is a deficiency of methionine and cysteine, it can lead to hair loss and brittle nails. Experiments in animals have shown that the growth of hair can be accelerated by taking methionine both with and without cysteine.(7)

When and for whom is it useful to take L-methionine?

If you suffer from one of the diseases mentioned or have the symptoms mentioned, taking L-methionine can be useful.

However, we advise you to consult your doctor in any case and discuss the administration and the associated dosage.

Because the intake of L-methionine should not be taken lightly, as an overdose can lead to side effects.

L-methionine can lead to interactions with certain medications, so consultation with your doctor is necessary. It is known that L-methionine can reduce the effectiveness of medications for Crohn's disease that contain the active ingredient L-dopa. Furthermore, the effectiveness of certain antibiotics can be increased excessively.

Administration of L-methionine is strongly discouraged to groups of people suffering from a congenital metabolic disorder (homocysteinuria), renal insufficiency, oxalosis, methionine adensoyltransferase deficiency, uric acid and cystine stone disorders. Infants should also not be given L-methionine.

How much L-methionine should be taken daily?

A healthy adult should take in about 21 mg of L-methionine per kilogram of body weight per day, although certain diseases and accompanying circumstances can lead to a two to three times higher requirement.

For example, existing allergies, liver disorders or urinary tract infections can significantly increase the methionine requirement.

Conversely, the administration of L-methionine can have a negative effect on many clinical pictures and should therefore be avoided in the case of gout, acidosis and schizophrenia.

What side effects are known from taking L-methionine?

The risk of taking L-methionine lies less in the side effects than in an overdose, which can lead to increased homocysteine levels. The following symptoms are among the most common side effects of methionine:

  • Acidosis
  • Fatigue
  • Gastrointestinal complaints
  • Irritability

Long-term intake or overdose of L-methionine can increase homocysteine levels, which is dangerous to health. Homocysteine is a toxic key product of L-methionine that should be disposed of from the body as soon as possible.

Therefore, homocysteine levels should be checked during and before treatment, as larger amounts can have negative effects on the organism. For example, homocysteine increases the risk of osteoporosis.

A medically justifiable homocysteine blood level should be below 10 µmol/l.

In larger amounts, homocysteine has a negative effect on memory, blood vessels and bones.

What is the alternative to L-methionine?

The daily requirement of L-methionine can be met through a balanced diet. The sulphur-containing amino acid is found in both animal and plant foods. Brazil nuts are the number one source of the bound form of L-methionine.

L-Methionin-2

Brazil nuts are a great way to provide your body with methionine naturally.
(Image source: Geraldine Dukes/pixabay)

The following table refers to the content of L-methionine per 100 grams of the respective food.

Food with L-methionine per 100 grams methionine/cysteine in milligrams
Brazil nuts 1008 mg
Salmon 700 mg
Prawns 670 mg
Turkey, breast meat 630 mg
Chicken breast fillet 620 mg
Sesame seeds 586 mg
Soybeans 580 mg
Beef fillet 570 mg
Cashew nuts 380 mg
Wheat germ 280 mg
Emmental cheese 250 mg
Walnuts 236 mg

Decision: What types of L-methionine are there and which is right for you?

If you want to take L-methionine, this is possible via oral administration. There are three main forms:

  • L-methionine in powder form
  • L-methionine in capsules
  • L-methionine in tablet form

In the following, we will explain the different types and their characteristics. In this way, we want to help you find the best L-methionine supplement for you.

What distinguishes L-methionine powder and what are the advantages and disadvantages?

L-methionine powder is one possible form of administration. The powder has a white to light yellow colour and can be ordered in different pack sizes.

One advantage of powder is that it is easier to swallow than tablets or capsules when dissolved in sufficient liquid. To measure the amount you need, you need a scale that works in the milligram range. Mixing the powder into a drink or food can be a tasty alternative to capsules and tablets.

Advantages
  • Can be mixed under food
  • Can be dosed individually
  • Better to swallow than tablets and capsules
Disadvantages
  • Harder to dose
  • Risk of overdose
  • Not practical for travelling
  • More expensive in comparison

What are the advantages and disadvantages of L-methionine capsules?

A second option is to take capsules. This form of administration is very popular with most customers because it is best suited for everyday use and has the best price-performance ratio. Compared to powder, capsules are more productive and cheaper.

A clear advantage is that they are easy to take on the go. All you need is the capsule and a little water. Most suppliers recommend taking L-methionine with meals during the day. The amount of L-methionine is already dosed and you do not need to measure it yourself with a scale.

Advantages
  • Very good price-performance ratio
  • Can be taken on the go
  • Are already dosed
Disadvantages
  • Some customers find swallowing capsules unpleasant (=danger of swallowing)
  • One capsule usually contains 500 mg L-methionine. If you need more or less, this is not practical for you

What are the advantages and disadvantages of L-methionine tablets?

Tablets are another form of L-methionine. The advantage is that you can take them with you everywhere and they are therefore also suitable for travelling.

Similar to capsules, they can be bulky to swallow for some people. You cannot dose them yourself, except roughly by dividing them into halves or quarters.

They are slightly more expensive than capsules, but cheaper than powder. You will usually find the capsule form on the market because it is more popular with most customers and the contents are easier to dose.

Advantages
  • Good value for money
  • Can be taken on the go
Disadvantages
  • Some customers find swallowing tablets unpleasant (=danger of swallowing)
  • one tablet usually contains 500 mg L-methionine and can therefore not be dosed by the customer

Buying criteria: You can use these factors to compare and evaluate L-methionine

Amount of L-methionine

In principle, capsules and tablets are very economical and cheaper than powder. The amount of L-methionine also depends on your individual purpose and the dosage prescribed by your doctor.

L-Methionin-3

Capsules are the best choice in terms of price-performance ratio
(Image source: lore.com/unsplash)

Generally speaking, you can get by for longer with more milligrams of L-methionine and then get out cheaper overall.

Ingredients

We recommend that you buy high-quality L-methionine. Such products should contain various B vitamins (B6, B12 and folic acid).

With the help of the B vitamins, the cell toxin homocysteine can be converted into cysteine.

Some suppliers do not use a large number of artificial additives and emphasise that their production is GMO-free. Chemical ingredients or substances such as gluten, lactose, fructose, which can trigger allergies, are avoidable.

Vegan or animal L-methionine

In many capsules, the shell is made of a vegan material (e.g. cellulose), but the source of the methionine can also be of animal or plant origin.

L-Methionin-5

Vegan capsules consist of vegan methionine and vegan shells
(Image source: vegan liftz/unsplash)

In the animal version, the L-methionine is obtained from animals and in the vegan version it is produced with the help of bacteria through natural fermentation.

If this difference is important to you, you should look for vegan methionine when buying.

Facts worth knowing about L-methionine

What is the shelf life of L-methionine?

The average shelf life of L-methionine is 1 to 2 years. You can find more detailed information on the shelf life on the package leaflet.

If the packaging is opened, the shelf life is reduced to 4 to months. To be on the safe side, you should read the information provided by the respective supplier.

Can I give L-methionine to my pet?

L-methionine is also given to animals for urinary tract disorders, but you should discuss its use with a veterinarian, as overdose can lead to a variety of side effects. (https://www.ncbi.nlm.nih.gov/pubmed/14640482

L-Methionin-6

Even dogs and cats are not immune to urinary tract infections. Hypothermia is a common cause of UTIs, so care must be taken to keep the bladder warm.
(Image source:Henry Matthews/unsplash)

Especially in a vegan diet of dogs and cats methionine administration is assessed as useful from a veterinary perspective, as the sulphur-containing amino acid would otherwise be poorly absorbed.

How could I recognise a deficiency of L-methionine myself?

You can recognise signs of an L-methionine deficiency yourself by the following symptoms.

  • brittle hair, nails
  • Wound healing disorders
  • Susceptibility to infections
  • possibly sleep disorders

L-Methionin-7

Since hair is made of keratin, which in turn is made of methionine, taking methionine can strengthen the hair roots
(Image source: pixabay/Kania)

To confirm this assumption, you should have a blood test done in the laboratory. Your blood plasma will be analysed. It is also possible to measure L-methionine in your urine, but this is more time-consuming because it is not just one sample.

Photo source: Klochan/ 123rf.com

References (7)

1. Methionine supplementation reversed the above changes except decreased liver glycogen due to arsenic treatment. It may be suggested that hypoglycemia with associated decreased glycolytic activity induced by arsenic treatment at the present dose and duration can be partially counteracted by dietary methionine supplementation
Source

2. No acute infection occurred during L-methionine treatment. All parameters of inflammation (leucocyte count, C-reactive protein, blood sedimentation rate, alpha 2-globulin concentration) were in the normal range; no impairment of renal function was observed. Although L-methionine, i.e. nalidixic acid, did not yield any significant changes in the range of bacteria, the adherence of uropathogenic microorganisms to the cells of the urinary tract was reduced.
Source

3. Upon treatment with L-Met, the otherwise recalcitrant PA biofilm now shows susceptibility to ciprofloxacin. This was reflected in vivo, in the murine chronic PA lung infection model. Mice treated with L-Met responded better to antibiotic treatment, leading to enhanced survival as compared to mice treated with ciprofloxacin alone. These results clearly demonstrate that L-Met can be used along with antibiotic as an effective therapeutic against chronic PA biofilm infection. Upon treatment with L-Met, the otherwise recalcitrant PA biofilm now shows susceptibility to ciprofloxacin. This was reflected in vivo, in the murine chronic PA lung infection model. Mice treated with L-Met responded better to antibiotic treatment, leading to enhanced survival as compared to mice treated with ciprofloxacin alone. These results clearly demonstrate that L-Met can be used along with antibiotic as an effective therapeutic against chronic PA biofilm infection.
Source

4. The present findings show that L-methionine effectively decreases urinary pH and the risk of struvite and calcium phosphate stone formation in healthy subjects. Hypercalciuria is not expected to occur at physiological doses of L-methionine.
Source

5. Recent research has demonstrated that methionine can regulate metabolic processes, the innate immune system, and digestive functioning in mammals. It also intervenes in lipid metabolism, activation of endogenous antioxidant enzymes such as methionine sulfoxide reductase A, and the biosynthesis of glutathione to counteract oxidative stress. In addition, methionine restriction prevents altered methionine/transmethylation metabolism, thereby decreasing DNA damage and carcinogenic processes and possibly preventing arterial, neuropsychiatric, and neurodegenerative diseases
Source

6. In generalized estimating equation analyses, melanin index and ultraviolet spots of all sites including face and arm when given GSH and GSSG tended to be lower than placebo. At some sites evaluated, subjects who received GSH showed a significant reduction in wrinkles compared with those taking placebo. A tendency toward increased skin elasticity was observed in GSH and GSSG compared with placebo. There were no serious adverse effects throughout the study.
Source

7. The results showed that the addition of dietary Methionine could significantly increase the HF density on dorsal skin (p < .05) and enhance the protein expression level of Wnt10b (p < .05), β-catenin (p < .05) and DSH (p < .05). Methionine stimulation could also prolong the hair shafts growth in vitro (p < .05). And inhibition of Wnt/β-catenin signalling using XAV-939 could eliminate this phenomenon. In summary, Met can increase the density of HFs on dorsal skin in vitro and prolong the hair shaft growth of HFs in vivo via the Wnt/β-catenin signalling pathway.
Source

Why you can trust me?

Protective effect of methionine supplementation on arsenic-induced alteration of glucose homeostasis.Pal, Chatterjee . Mai 2004.
Methionine supplementation reversed the above changes except decreased liver glycogen due to arsenic treatment. It may be suggested that hypoglycemia with associated decreased glycolytic activity induced by arsenic treatment at the present dose and duration can be partially counteracted by dietary methionine supplementation
Go to source
Prevention of reinfection by L-methionine in patients with recurrent urinary tract infection. Fünfstück R1, Straube E, Schildbach O, Tietz U.1997 Oct 15
No acute infection occurred during L-methionine treatment. All parameters of inflammation (leucocyte count, C-reactive protein, blood sedimentation rate, alpha 2-globulin concentration) were in the normal range; no impairment of renal function was observed. Although L-methionine, i.e. nalidixic acid, did not yield any significant changes in the range of bacteria, the adherence of uropathogenic microorganisms to the cells of the urinary tract was reduced.
Go to source
Chronic lung infection by Pseudomonas aeruginosa biofilm is cured by L-Methionine in combination with antibiotic therapy.Gnanadhas, Elango.2.November.2015
Upon treatment with L-Met, the otherwise recalcitrant PA biofilm now shows susceptibility to ciprofloxacin. This was reflected in vivo, in the murine chronic PA lung infection model. Mice treated with L-Met responded better to antibiotic treatment, leading to enhanced survival as compared to mice treated with ciprofloxacin alone. These results clearly demonstrate that L-Met can be used along with antibiotic as an effective therapeutic against chronic PA biofilm infection. Upon treatment with L-Met, the otherwise recalcitrant PA biofilm now shows susceptibility to ciprofloxacin. This was reflected in vivo, in the murine chronic PA lung infection model. Mice treated with L-Met responded better to antibiotic treatment, leading to enhanced survival as compared to mice treated with ciprofloxacin alone. These results clearly demonstrate that L-Met can be used along with antibiotic as an effective therapeutic against chronic PA biofilm infection.
Go to source
Effect of L-Methionine on the Risk of Phosphate Stone Formation. Struwe, Hesse. Dezember 2016.
The present findings show that L-methionine effectively decreases urinary pH and the risk of struvite and calcium phosphate stone formation in healthy subjects. Hypercalciuria is not expected to occur at physiological doses of L-methionine.
Go to source
The role of methionine on metabolism, oxidative stress, and diseases.Martínez .Y, Li.X. Dezember2017.
Recent research has demonstrated that methionine can regulate metabolic processes, the innate immune system, and digestive functioning in mammals. It also intervenes in lipid metabolism, activation of endogenous antioxidant enzymes such as methionine sulfoxide reductase A, and the biosynthesis of glutathione to counteract oxidative stress. In addition, methionine restriction prevents altered methionine/transmethylation metabolism, thereby decreasing DNA damage and carcinogenic processes and possibly preventing arterial, neuropsychiatric, and neurodegenerative diseases
Go to source
Glutathione and its antiaging and antimelanogenic effects.Sinee Weschawalit, Siriwan Thongthip. 2017.
In generalized estimating equation analyses, melanin index and ultraviolet spots of all sites including face and arm when given GSH and GSSG tended to be lower than placebo. At some sites evaluated, subjects who received GSH showed a significant reduction in wrinkles compared with those taking placebo. A tendency toward increased skin elasticity was observed in GSH and GSSG compared with placebo. There were no serious adverse effects throughout the study.
Go to source
Methionine promotes the development of hair follicles via the Wnt/β-catenin signalling pathway in Rex rabbits.Zhu , Wu Z. 15.November.2019
The results showed that the addition of dietary Methionine could significantly increase the HF density on dorsal skin (p < .05) and enhance the protein expression level of Wnt10b (p < .05), β-catenin (p < .05) and DSH (p < .05). Methionine stimulation could also prolong the hair shafts growth in vitro (p < .05). And inhibition of Wnt/β-catenin signalling using XAV-939 could eliminate this phenomenon. In summary, Met can increase the density of HFs on dorsal skin in vitro and prolong the hair shaft growth of HFs in vivo via the Wnt/β-catenin signalling pathway.
Go to source
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