Tryptophan is alpha-aminoacid that is used in the biosynthesis of proteins. It is essential aminoacid in humans, meaning the body cannot synthesize and it must be obtained from the diet. Tryptophan is a precursor of serotonin, and as such is sold over the counter in many countries as a dietary supplement for use as an antidepressant, anxiolytic and sleep aid, however application of tryptophan in these indications is not approved by FDA.

Alanine is a non-essential aminoacid encoded by GCU, GCC, GCA, and GCG codons. Besides being a building block of proteins, alanine plays a key role in glucose-alanine cycle. Alanine is medically used as a dietary supplement for conditions such as fructose intolerance, muscle atrophy, low birth weight.

Isoleucine is an essential α-amino acid that is used in the biosynthesis of proteins. L-isoleucine is commonly used in parenteral and enteral nutrition. It is used in combination with the other branched chain amino acids to improve the nutritional status of patients with hepatic diseases. BCAAs serve as important fuel sources for skeletal muscle during periods of metabolic stress

Lysing is an essential basic amino-acid encoded by codone AAA and AAG, and used in the biosynthesis of proteins. The daily requirement for lysine is 38 mg/kg body weight. The most rich source of lysine is fish, beef, chicken. In a clinical study lysine supplements was found to be an effective for reduction of occurrence, severity and healing time for recurrent HSV infection, however Cochrane Review concluded that the evidence is insufficient. Lysine was investigated for improving anxiety, ameliorating angina prectoris. Lysine acetylsalicylate has been used to treat pain and to detoxify the body after heroin use. Lysine clonixinate has been used for its analgesic properties for the treatment of migraine headaches and other painful conditions. However, limited clinical trials exist for these conditions.

Histidine is an essential amino acid. L-histidine is converted to histamine by histidine decarboxylase, a pyridoxal 5'-phosphate-dependent enzyme. The copper(II)–l-histidine (1:2 complex at physiological pH) has been widely used in the treatment of Menkes disease (a genetic neurodegenerative disorder that leads to early death in the children due to impaired copper metabolism) and more recent use has been reported in the treatment of infantile hypertrophic cardioencephalomyopathy (a condition caused by mutations in SCO2, a cytochrome c oxidase assembly gene). CUSTODIOL HTK (Histidine-tryptophan-ketoglutarate) Solution is indicated for perfusion and flushing of donor kidneys, liver, and heart prior to removal from the donor or immediately after removal from the donor.

Valine is an α-amino acid that is used in the biosynthesis of proteins. It is essential in humans, meaning the body cannot synthesize it and thus it must be obtained from the diet. There is a mixed scientivic evidence that as a dietary supplement valine improves training efficacy, delays central fatigue.

Clofibrate is a fibric acid derivative used to lower cholesterol and triglyceride (fat-like substances) levels in the blood. This may help prevent medical problems caused by such substances clogging the blood vessels. However, this treatment was discontinued in 2002 due to adverse effects. Clofibrate is an agonist of the PPAR-α receptor in muscle, liver, and other tissues. This agonism ultimately leads to modification in gene expression resulting in increased beta-oxidation, decreased triglyceride secretion, increased HDL, and increased lipoprotein lipase activity. Clofibrate increased the activity of extrahepatic lipoprotein lipase (LL), thereby increasing lipoprotein triglyceride lipolysis, inhibited the synthesis, and increases the clearance of apolipoprotein B, a carrier molecule for VLDL. In addition, clofibrate was investigated as a novel therapy agent in multiple myeloma and it shown the promising results.

Tyrosine (L-form) is a non-essential amino acid, which is primarily required for the protein synthesis. This amino acid is the precursor of dopamine, norepinephrine, and epinephrine; therefore the lower concentration of tyrosine could be a peripheral marker of the hyperdopaminergic condition hypothesized to explain psychosis. Tyrosine supplements can improve cognition, increase energy, reduce anxiety, reduce depression, reduce levels of pain.

Glutethimide is a GABA agonist that was introduced by Ciba in 1954 as a safe alternative to barbiturates to treat insomnia. Before long, however, it had become clear that glutethimide was just as likely to cause addiction and caused similarly severe withdrawal symptoms. Glutethimide was discontinued in the US by manufacturers in 1993. Current production levels in the United States point to it only being used in small-scale research.

DL-Methionine is a racemic form of the respective sulfur aminoacid. DL-Methionine participates in synthesis of tissue proteins, vitamins, enzymes and hormones taking part in nitrogen, carbohydrate and fat metabolisms, and it is the important source of methyl groups for synthesis of all nucleic acids, as well as the sulfur source for sulfonic compounds. Methionine is used to prevent liver damage in acetaminophen (Tylenol) poisoning. It is also used for increasing the acidity of urine, treating liver disorders, and improving wound healing. Other uses include treating depression, alcoholism, allergies, asthma, copper poisoning, radiation side effects, schizophrenia, drug withdrawal, and Parkinson's disease. It is also used as a food additive in livestock to boost performance. DL-Methionin is the first limiting amino acid in poultry, and probably also in high-yielding cows, and is the second or third limiting amino acid in pigs fed conventional diets.