The selenite anion is a selenium oxoanion with the chemical formula SeO2−3. A selenite (Se) is a compound that contains this ion. Sodium selenite is an inorganic form of the trace element selenium with potential antineoplastic activity. It was documented that Se deficiency observed in some countries and/or geographic regions (e.g. Keshan region in China), is associated with an increased morbidity and mortality of neoplastic diseases. To correct this problem a number of organic and inorganic selenium compounds were developed and tested. However, it is now firmly established that only an inorganic sodium selenite with four-valent Se, and not that with six-valent (selenate) cation shows anticancer activity. Selenite can undergo redox reaction, for example with protein's sulfhydryl groups expressed on the surface of tumor cells. In this way selenite prevents non-enzymatic formation of parafibrin that coats tumors cells and hence presents them as 'self' to the innate cellular immune system. Consequently, macrophages of the lymphatic system do not recognize neoplastic cells as 'foreign' bodies and spare them from the immune destruction. Sodium selenite also showed promise as a cost-effective, nontoxic anti-inflammatory agent. Treatment with sodium selenite lowers reactive oxygen species (ROS) production, causes a spontaneous reduction in lymphedema volume, increases the efficacy of physical therapy for lymphedema, and reduces the incidence of erysipelas infections in patients with chronic lymphedema. Limited evidence has been presented though that intakes of selenium greater than the amount needed to allow full expression of selenoproteins may have chemopreventive effects against cancer. Controlled intervention studies are needed to fully evaluate selenium as a cancer chemopreventive agent. The US Food and Drug Administration approved a selenium supplement to animal diets; the most common form is sodium selenite for pet foods.

Testosterone is a steroid sex hormone found in both men and women. In men, testosterone is produced primarily by the Leydig (interstitial) cells of the testes when stimulated by luteinizing hormone (LH). It functions to stimulate spermatogenesis, promote physical and functional maturation of spermatozoa, maintain accessory organs of the male reproductive tract, support development of secondary sexual characteristics, stimulate growth and metabolism throughout the body and influence brain development by stimulating sexual behaviors and sexual drive. In women, testosterone is produced by the ovaries (25%), adrenals (25%) and via peripheral conversion from androstenedione (50%). Testerone in women functions to maintain libido and general wellbeing. Testosterone exerts a negative feedback mechanism on pituitary release of LH and follicle-stimulating hormone (FSH). Testosterone may be further converted to dihydrotestosterone or estradiol depending on the tissue. The effects of testosterone in humans and other vertebrates occur by way of two main mechanisms: by activation of the androgen receptor (directly or as DHT), and by conversion to estradiol and activation of certain estrogen receptors. Free testosterone (T) is transported into the cytoplasm of target tissue cells, where it can bind to the androgen receptor, or can be reduced to 5α-dihydrotestosterone (DHT) by the cytoplasmic enzyme 5α-reductase. DHT binds to the same androgen receptor even more strongly than T, so that its androgenic potency is about 2.5 times that of T. The T-receptor or DHT-receptor complex undergoes a structural change that allows it to move into the cell nucleus and bind directly to specific nucleotide sequences of the chromosomal DNA. The areas of binding are called hormone response elements (HREs), and influence transcriptional activity of certain genes, producing the androgen effects. Testosterone is used as hormone replacement or substitution of diminished or absent endogenous testosterone. Use in males: For management of congenital or acquired hypogonadism, hypogonadism associated with HIV infection, and male climacteric (andopause). Use in females: For palliative treatment of androgen-responsive, advanced, inoperable, metastatis (skeletal) carcinoma of the breast in women who are 1-5 years postmenopausal; testosterone esters may be used in combination with estrogens in the management of moderate to severe vasomotor symptoms associated with menopause in women who do not respond to adequately to estrogen therapy alone.

Phosphate is a major intracellular anion in mammals. Hydrogen phopshate is a protonated form of phosphate. In serum, phosphate exists in two forms, dihydrogen phosphate (H2PO4) and its salt, mono-hydrogen phosphate (HPO4). At the physiologic pH of 7.40, the pK of H2PO4 is 6.8 and the ratio of HPO4 to H2PO4 is 4:1. Altered level of phosphate can be an indicator of various disorders, such as chronic renal failure, hypoparathyroidism, familial intermittent hyperphosphatemia, endocrine disorders, hyperthyroidism, acromegaly, juvenile hypogonadism, etc. These disorders may lead to either hyper- or hypophosphatemia, which can be caused by cellular shifts of phosphate. Patients with hypophosphatemia can be treated with dietary phosphate supplements (potassium phosphate, for example).

Nitrite Ion is a symmetric anion with equal N–O bond lengths. Nitrite is important in biochemistry as a source of the potent vasodilator nitric oxide. Nitrate or nitrite (ingested) under conditions that result in endogenous nitrosation has been classified as "Probably carcinogenic to humans" (Group 2A) by International Agency for Research on Cancer (IARC), the specialized cancer agency of the World Health Organization (WHO) of the United Nations. Sodium nitrite is used for the curing of meat because it prevents bacterial growth and, as it is a reducing agent (opposite of oxidation agent), in a reaction with the meat's myoglobin, gives the product a desirable pink-red "fresh" color, such as with corned beef. This use of nitrite goes back to the Middle Ages, and in the US has been formally used since 1925. Because of the relatively high toxicity of nitrite (the lethal dose in humans is about 22 milligrams per kilogram of body weight), the maximum allowed nitrite concentration in meat products is 200 ppm. At these levels, some 80 to 90% of the nitrite in the average U.S. diet is not from cured meat products, but from natural nitrite production from vegetable nitrate intake. Under certain conditions – especially during cooking – nitrites in meat can react with degradation products of amino acids, forming nitrosamines, which are known carcinogens. However, the role of nitrites (and to some extent nitrates) in preventing botulism by preventing C. botulinum endospores from germinating have prevented the complete removal of nitrites from cured meat, and indeed by definition in the U.S., meat cannot be labeled as "cured" without nitrite addition. They are considered irreplaceable in the prevention of botulinum poisoning from consumption of cured dry sausages by preventing spore germination. Nitrite is a member of the drug class antidotes and is used to treat Cyanide Poisoning.

Sodium thiosulfate (sodium thiosulphate/STS) is a chemical and medication. As a medication, it is used in combination with sodium nitrite under the trade name to NITHIODOTE treat cyanide poisoning. The primary route of endogenous cyanide detoxification is by enzymatic transulfuration to thiocyanate (SCN- ), which is relatively nontoxic and readily excreted in the urine. Sodium thiosulfate is thought to serve as a sulfur donor in the reaction catalyzed by the enzyme rhodanese, thus enhancing the endogenous detoxification of cyanide. In addition, Sodium thiosulfate is used in calciphylaxis in hemodialysis patients with end-stage kidney disease. Calciphylaxis is vasculopathy characterized by ischemia and painful skin necrosis due to calcification and intimal fibroplasia of thrombosis of the panicular arterioles. Sodium thiosulfate is used as treatment due to its antioxidant activity and as a chelating. Sodium thiosulfate renders renal protection by modulating the mitochondrial KATP channel for preventing urolithiasis. Moreover, STS was assumed to play a vital role in on ischemia reperfusion injury (IR). The effectiveness of STS as a cardioprotective agent was attributed to the reduction of apoptosis by binding to the active site of caspase-3 in silico, which was substantiated by the reduced expression of caspase-3 and poly ADP ribose polymerase levels.

SULFATE (as sodium sulfate, potassium sulfate, and magnesium sulfate) is a component of SUPREP Bowel Prep Kit. It is an osmotic laxative indicated for cleansing of the colon in preparation for colonoscopy in adults. Sulfate salts provide sulfate anions, which are poorly absorbed. The osmotic effect of unabsorbed sulfate anions and the associated cations causes water to be retained within the gastrointestinal tract. SUPREP Bowel Prep Kit, when ingested with a large volume of water, produces copious watery diarrhea.

Acetic acid (a component of vinagre) is used in medicine for the treatment of otitis externa caused by bacterial infections. The solution containing acetic acid was approved by FDA.

Monofluorophosphate (MFP) is an anion, which is a phosphate group with one oxygen atom substituted with a fluorine atom. Sodium Monofluorophosphate is intended to be used by both petitioners in food supplements as a source of fluoride in the forms of multi-vitamin, multi-mineral supplements, solid tablets or tablets dispersible in liquid. The toxic effects of Monofluorophosphate are attributable to the fluoride ion released by the in vivo hydrolysis of the parent compound. The Monofluorophosphate ion appears to play no role. The acute toxicity of Monofluorophosphate is somewhat less than that of NaF, due to the lesser availability of fluoride in the short term from Monofluorophosphate. In the long term, Monofluorophosphate produces virtually the same picture of renal effects and skeletal storage of fluoride as does NaF. Sodium Monofluorophosphate dissociates into sodium and Monofluorophosphate ions in the intestinal tract, the latter being absorbed mainly in the upper small intestine.

Olaflur (amine fluoride 297, trade name elmex gel) is a fluoride-containing substance that is an ingredient of toothpastes and solutions for the prevention of dental caries. Especially in combination with dectaflur, it is also used in the form of gels for the treatment of early stages of caries, sensitive teeth, and by dentists for the refluoridation of damaged tooth enamel. Olaflur is a salt consisting of an alkyl ammonium cation and fluoride as the counterion. With a long lipophilic hydrocarbon chain, the cation has surfactant properties. It forms a film layer on the surface of teeth, which facilitates incorporation of fluoride into the enamel. The top layers of the enamel's primary mineral, hydroxylapatite, are converted into the more robust fluorapatite. The fluoridation reaches only a depth of a few nanometres, which has raised doubts whether the mechanism really relies on the formation of fluorapatite.

Potassium citrate is indicated for the management of renal tubular acidosis with calcium stones, hypocitraturic calcium oxalate nephrolithiasis of any etiology, uric acid lithiasis with or without calcium stones. WhenPotassium citrate is given orally, the metabolism of absorbed citrate produces an alkaline load. The induced alkaline load in turn increases urinary pH and raises urinary citrate by augmenting citrate clearance without measurably altering ultrafilterable serum citrate. Thus, potassium citrate therapy appears to increase urinary citrate principally by modifying the renal handling of citrate, rather than by increasing the filtered load of citrate. Potassium citrate is used as a food additive (E 332) to regulate acidity.