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 2022. 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.
- 1 Weekly newsletter with the best personal finance tips
- 2 Summary
- 3 The Best L-Methionine: Our Picks
- 4 Guide: Questions you should ask yourself before buying L-methionine
- 5 Decision: What types of L-methionine are there and which is right for you?
- 6 Buying criteria: You can use these factors to compare and evaluate L-methionine
- 7 Facts worth knowing about L-methionine
- 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?
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.
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 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?
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?
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?
- Gastrointestinal complaints
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 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|
|Turkey, breast meat||630 mg|
|Chicken breast fillet||620 mg|
|Sesame seeds||586 mg|
|Beef fillet||570 mg|
|Cashew nuts||380 mg|
|Wheat germ||280 mg|
|Emmental cheese||250 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.
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.
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.
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.
Generally speaking, you can get by for longer with more milligrams of L-methionine and then get out cheaper overall.
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.
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
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
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.
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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
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.
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.
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.
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
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.
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.