Supplementation with methionine is appropriate in certain situations to boost the body’s defenses, but this compound should be used with caution.
What is Methionine?
Methionine is an essential amino acid in the body and is often referred to as L-Methionine. This amino acid happens to be a critical component in the production of many other things, including creatine, and new blood vessels throughout the body. Most importantly perhaps, methionine is a precursor to taurine and cysteine, two other amino acids. It is also connected to the creation of cartilage. Basically, having a proper level of this amino acid is very important to the normal function of the body, as well as repair processes. 
As we age, our body produces less of this and every other amino acid, which may require supplementation. That being said, having too much of this in the body can also be dangerous, as it can lead to major chronic diseases. It is important to speak with your doctor before using supplementation with methionine or shifting your diet to include foods that deliver natural forms of this amino acid.
If you want to increase the amount of this amino acid in your body, particularly if you are trying to increase muscle growth and boost energy metabolism, try eating more of the following foods:
- Egg whites
- Sesame seeds
- Brazil nuts
These foods are also excellent sources of methionine. It also isn’t difficult to make small adjustments in your diet to boost your methionine levels. That being said, if you are experiencing a serious deficiency of this amino acid, supplementation may be necessary. 
The many benefits of methionine include its impact on the following:
- Urinary tract infections
- Toxicity levels in the body
- Bone mineral density
- Parkinson’s diseases
- Immune system
- Colorectal cancer
- Weight loss efforts
Let us discuss them in detail below.
Some research has shown that a deficiency in this compound is linked to Parkinson’s disease, so ensuring that this amino acid is in your diet can help to counter or mitigate the effects of this debilitating neurodegenerative disease. 
As mentioned, methionine is one of the key ingredients in creatine, which improves muscle development, at the expense of fat. This can help to increase your metabolic rate and aid in weight loss efforts. 
Bone Mineral Density
Many athletes choose this supplement because it can aid in bone development and strength, which is very necessary for athletes, particularly if they have suffered an injury of some kind. 
It has been found that having proper levels of methionine in the body is correlated with the presence of other amino acids, many of which are instrumental in the function of the immune system. Methionine is a precursor for some of these immune-boosting amino acids that can aid in defense and repair.
Urinary Tract Infections
Methionine can slightly acidify the body when taken in supplement form, which means that it can also make the urine slightly more acidic. In this type of environment, it is difficult for urinary tract infections to take hold, thus protecting women from this uncomfortable problem, specifically those who have recurring UTIs. 
In the presence of other nutrients and compounds, this compound can stimulate liver function and lessen the effects of liver disease, thus detoxifying much of the body in the process. 
Specific research has been conducted on methionine’s effects on colorectal cancer, both in terms of risk prevention and treatment. High amino acid levels can ensure proper antioxidant formation in the body – namely, glutathione – so supplementation with methionine may be required for those at risk for chronic diseases. 
How to Use Methionine?
First and foremost, if you want to access this amino acid in foods, it is very important not to expose the foods to high temperatures for extended periods of time, as this can cause the amino acids to become denatured and no longer provide any benefits in the body. However, if you want to use supplementation, it is important to know what dosage to consume. If you are taking a pure supplement, do not consume more than 500 milligrams per day. However, you may also find this particular amino acid in a general amino acid supplement; the chance of consuming an excess in this context is unlikely.
Methionine Side Effects
As mentioned earlier, having a proper balance of this amino acid is critical, as having too much or too little can both be dangerous. Some of the side effects of consuming too much methionine include the following:
- Nausea and vomiting
- Higher risk of liver disease
- Complications for pregnant women
- Bad breath (halitosis)
Before using this supplement, it is a wise choice to speak with your doctor, particularly if you are taking any other medications or have pre-existing conditions.