Beta-alanine is an endogenous agonist of glycine receptor, which is used a supplementation among competitive athletes participating in a range of different sports. Beta-alanine has been shown to enhance muscular endurance and its supplementation appears to be most effective for exercise tasks that rely heavily on ATP synthesis from anaerobic glycolysis.

Bilirubin is an orange-yellow pigment made during the normal breakdown of red blood cells. Bilirubin passes through the liver and is excreted out of the body. Occasionally, higher bilirubin levels may indicate an increased rate of destruction of red blood cells (hemolysis). A high level of bilirubin in the blood is called hyperbilirubinemia. High bilirubin levels can cause jaundice. Jaundice makes the skin and the whites of the eyes appear yellow, due to the brown and yellow bilirubin in the blood. Phototherapy for neonatal is one of the treatment methods against hyperbilirubinemia. Light absorption by bilirubin in the skin transforms the native Z,Z-bilirubin to conformational photoisomers Z,E-bilirubin and E,Z-bilirubin and structural photoisomers E,Z-lumirubin and E,E-lumirubin. Formation and excretion of Z,E-bilirubin and E,Z-lumirubin are both important routes of elimination of bilirubin through bile and urine, although the precise contributions of the various photoisomers to the overall elimination of bilirubin are still unknown.

Trimethylamine (or TMA) a tertiary amine, is synthesized by the action of microbial enzymes in humans. The decrease of TMA metabolism and excessive TMA excretion cause the disease trimethylaminuria and some other diseases associated with the abnormal level of TMA, e.g., obesity, diabetes, cardiovascular diseases. It was shown, that TMS is a full agonist of human trace amine-associated receptor 5, TAAR5. In addition, TMA is a precursor of N-oxide form, an emergent biomarker of human health that can lead to renal diseases, neurological disorders, and cancer.

Estriol (E3), also spelled oestriol, is a steroid, a weak agonist of the estrogen receptors ERα and ERβ., and a minor female sex hormone. According to in vitro study, the relative binding affinity (RBA) of estriol for the human ERα and ERβ was 11.3% and 17.6% of that estradiol, respectively, and the relative transactivational capacity of estrone at the ERα and ERβ was 10.6% and 16.6% of that of estradiol, respectively. Estriol is marketed widely in Europe and elsewhere throughout the world under the brand names Ovestin, Ortho-Gynest, and a variety of others. It is available in oral tablet, vaginal cream, and vaginal suppository form, and is used in menopausal hormone therapy for the treatment of menopausal symptoms. Estriol is also available in some countries as estriol succinate (brand name Synapause), a dosage-equivalent ester prodrug of estriol. Estriol and estriol succinate are not approved for use in the United States and Canada, although they have been produced and sold by compounding pharmacies in North America for use as a component of bioidentical hormone therapy. Estriol can be measured in maternal blood or urine and can be used as a marker of fetal health and well-being. If levels of unconjugated estriol (uE3 or free estriol) are abnormally low in a pregnant woman, this may indicate chromosomal or congenital anomalies like Down syndrome or Edward's syndrome. It is included as part of the triple test and quadruple test for antenatal screening for fetal anomalies.

Cytosine is a pyrimidine nucleobase, one of the five main bases of nucleic acids. In DNA and RNA cytosine is paired with guanine. Only small amounts of cytosine administered with food are incorporated in DNA. The majority of cytosine is synthesized de-novo starting from carbamoyl phosphate.