I published on 2025-9-15 that peptide health products are all lies. There are a few sentences in it: When peptides enter the digestive tract, they will be broken down into amino acids, and these amino acids will be used by cells throughout our body to synthesize various peptides and proteins. Therefore, whether you eat bitter melon peptides, melon peptides, or sour melon peptides, your digestive tract will treat them equally and break them down into unit amino acids, and these unit amino acids will never have the effects claimed in the advertisements.
Shortly after this article was published, Facebook friend Patrick Lau responded: Nowadays, many skin care foods are directly based on amino acids.
Yes, there are indeed many amino acid health products on the market, and the advertisements are dazzling, such as the illustration below (the emoticon was added by me).
But in fact, amino acid health supplements are not only useless, but harmful. Especially the methionine supplement in the illustration, which is the most dangerous of all amino acid supplements. Studies have shown that high intakes of methionine increase the risk of diabetes and cardiovascular disease (heart disease, stroke) and death. Please see Eating too many sulfur amino acids may boost cardiovascular disease and death risk published by the American Heart Association on March 3, 2022 (Eating too many sulfur amino acids may boost cardiovascular disease and death risk) (please continue to read the research report below).
Excessive amino acid intake can lead to a variety of health problems, including nutritional imbalance, burden on the liver and kidneys, and potential negative effects on cardiovascular health and immune function. Some amino acids, such as sulfur-containing amino acids, pose special risks. Excessive intake of these amino acids increases the risk of cardiovascular disease and diabetes.
In terms of the most basic burden on the liver and kidneys, when the intake of amino acids exceeds the body's needs, the liver must work harder to break them down into urea, and then the kidneys must work harder to excrete urea from the body.
As far as specific risks are concerned, I will list several relevant papers and their highlights as follows:
1978: Nutritional Consequences of Excess Amino Acid Intake
1. All organs in our body will respond to excessive amino acid intake, for example, the catabolism of the liver will be accelerated.2. Changes in free amino acid levels in the brain will send signals to the nervous system centers that regulate food intake, thus affecting eating patterns. This central nervous system may even determine the ratio of protein to energy-producing nutrients in the diet through the mechanism by which tryptophan and other neurotransmitter precursors enter the brain.
2004: The Nature of Human Hazards Associated with Excessive Intake of Amino Acids (The harm of excessive intake of amino acids to the human body)
1. Adverse reactions will occur when the intake of most (if not all) amino acids is too high.2. The most toxic amino acids to animals and humans appear to be methionine, cysteine and histamine. Not only do these amino acids have acute adverse effects, there is evidence that they may cause tissue damage and increase homocysteine and/or cholesterol levels, so long-term use may be associated with chronic disease.
2022: Side Effects of Amino Acid Supplements
1. Increasing the intake of one or more amino acids will lead to an imbalance in the concentration of amino acids and increase the concentration of their metabolites.2. Increasing the uptake of a certain amino acid will also lead to competition for the carrier on the cell membrane, thereby affecting the transport of a group of amino acids into the cell. The phenomenon of carrier competition affects the intestinal absorption of other amino acids, which in turn affects their appearance in the blood, transport across the blood-brain barrier, and supply for protein synthesis.
3. In summary, it can be hypothesized that long-term ingestion of large amounts of single amino acids or their derivatives will alter various biochemical pathways and cellular functions. The consequences can be adverse effects on the course of the disease and unexpected responses to various physiological and pathological conditions.
2020: Association of sulfur amino acid consumption with cardiometabolic risk factors: Cross-sectional findings from NHANES III. Higher intakes of sulfur-containing amino acids, methionine, and cysteine were associated with significantly increased composite cardiometabolic disease risk scores and were associated with multiple individual risk factors, including serum cholesterol, glucose, uric acid, urea nitrogen, insulin, and glycated hemoglobin. (Note: Methionine is an essential amino acid that can be obtained through dietary intake; cysteine is derived from methionine)
2022: Cumulative Consumption of Sulfur Amino Acids and Risk of Diabetes: A Prospective Cohort Study (Cumulative Consumption of Sulfur Amino Acids and Risk of Diabetes: A Prospective Cohort Study). Conclusion: Our findings suggest that excessive intake of sulfur-containing amino acids increases the risk of type 2 diabetes.
2024: Identification of a leucine-mediated threshold effect governing macrophage mTOR signaling and cardiovascular risk. Dietary protein intake exceeding 22% can lead to the activation of immune cells, which play an important role in the formation of atherosclerotic plaques and increase the risk of disease. Leucine, in particular, appears to play a disproportionate role in driving pathological pathways associated with atherosclerosis (or stiffening, hardening of the arteries).
Finally, I quote Are there any risks associated with taking amino acid supplements? (Are there any risks associated with taking amino acid supplements?) published by Medicine Net on 2024-11-14. Taking amino acid supplements when they are not needed can be harmful. Just as too little protein is bad for your health, too much protein is bad for your health. Typically, a balanced diet that includes the recommended daily amount of protein will help you get all the essential amino acids. Many diets recommend eating high amounts of protein, but research shows that eating too much protein can lead to cardiovascular disease. In addition to side effects such as gastrointestinal upset, headaches, cramps, and pain, long-term use of amino acid supplements can increase the risk of hardening of the arteries (atherosclerosis), increasing the risk of stroke and heart disease.
Original text: Consequences of excessive amino acid intake