Sodium oxybate is the sodium salt of gamma-hydroxybutyrate (GHB), an endogenous metabolite of gamma-aminobutyric acid (GABA) a major inhibitory neurotransmitter. Evidence suggests a role for GHB as a neuromodulator/neurotransmitter. Under endogenous conditions and concentrations, and depending on the cell group affected, GHB may increase or decrease neuronal activity by inhibiting the release of neurotransmitters that are co-localised with GHB. After exogenous administration, most of the observed behavioural effects appear to be mediated via the activity of GHB at GABA(B) receptors, as long as the concentration is sufficient to elicit binding, which does not happen at endogenous concentrations. Xyrem (sodium oxybate) oral solution is indicated for the treatment of cataplexy in narcolepsy and excessive daytime sleepiness (EDS) in narcolepsy.

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).

Metanephrine (metadrenaline) is a metabolite of epinephrine (adrenaline) created by the action of catechol-O-methyl transferase on epinephrine. It is a commonly occurring, pharmacologically and physiologically inactive metabolite of epinephrine. The measurement of plasma free metanephrines is considered to be the best tool in the diagnosis of pheochromocytoma, a rare kind of adrenal medullary neoplasm. In adrenal chromaffin cells, leakage of norepinephrine and epinephrine from storage granules leads to the substantial intracellular production of the O-methylated metabolite metanephrine. In fact, the adrenals constitute the single largest source out of any organ system including the liver for circulating metanephrine. In humans, about 93 percent of circulating metanephrine is derived from catecholamines metabolized within adrenal chromaffin cells.

Phenylalanine is a biologically essential amino acid that acts as a precursor to tyrosine and the catecholamines (epinephrine, norepinephrine, dopamine, and tyramine), and is a constituent of many central nervous system neuropeptides. Normal dietary levels of phenylalanine are approximately 1-2 grams daily. Phenylalanine appears in two forms which are identical mirror images of each other: L-phenylalanine, a nutritional supplement, and D-phenylalanine, an effective painkiller and antidepressant due to its ability to inhibit the breakdown of enkephalins, the brain’s natural pain killers.

Creatinine is a product of metabolism of creatine phosphate, a molecule that serves as a rapidly mobilizable reserve of a brain and skeletal muscle. Creatinine is excreted by kidneys with little or no reabsorption. Serum creatinine is the most commonly used indicator of renal function.

HYDROXYPROLINE, a hydroxylated form of the imino acid proline, is a major component of the protein collagen. For this reason, HYDROXYPROLINE content in biological fluids is used as a parameter of collagen catabolism, especially bone resorption or tissue degradation. A deficiency in ascorbic acid can result in impaired HYDROXYPROLINE formation.

Serotonin (5-hydroxytryptamine, or 5-HT) is a monoamine neurotransmitter produced by serotonergic neurons in the CNS and enterochromaffin cells in the gastrointestinal tract. Pharmacologic action of serotonin is mediated by a large and diverse range of 5-HT receptors. Serotonin plays an important part in the biochemistry of depression, migraine, bipolar disorder, and anxiety. It is also believed to be influential on sexuality and appetite. Creatinine is a product of the metabolic breakdown of creatine phosphate in muscle. Creatinine is filtered by healthy kidneys. Serotonin creatinine sulfate complex was the first isolated salt form of serotonin.

Androstenedione (Δ4-Androstenedione, 4-androstene-3,17-dione or 17-ketotestosterone) is an endogenous androgen steroid hormone and intermediate in the biosynthesis of testosterone from dehydroepiandrosterone (DHEA). In turn, Androstenedione is also a precursor of dihydrotestosterone (DHT), estrogens such as estradiol and estrone, and the neurosteroid 3α-androstanediol. Androstenedione is used to increase the production of the hormone testosterone to enhance athletic performance, increase energy, keep red blood cells healthy, enhance recovery and growth from exercise, and increase sexual desire and performance. Androstenedione has been shown to increase serum testosterone levels over an eight-hour period in men when taken as a single oral dose of 300 mg per day, but a dose of 100 mg had no significant effect on serum testosterone. However, serum levels of estradiol increased following both the 100 mg and 300 mg doses. The study also reported that the serum level of estrogens and testosterone produced varied widely among individuals. Androstenedione is currently used as a nutritional supplement to grow bigger muscles and stronger bones. This implies that androstenedione may have anabolic properties. Even though it has not been convincingly demonstrated yet that androstenedione is an anabolic steroid, its anabolic properties are likely based on its proven ability to increase testosterone levels. The role of testosterone in building stronger muscles and bones is widely accepted. Thus, high doses of testosterone-boosting drugs combined with strength training have been shown to increase muscle size and strength even in normal young men. This confirms what thousands of athletes who take anabolic steroids have known for decades. Yet androstenedione is different from testosterone-boosting drugs in a number of important aspects. To begin with, androstenedione is a naturally occurring substance that is produced by the body itself. In contrast to synthetic anabolic steroids, androstenedione is right at home in the human body, and perfectly complements the complex hormonal network in the body. Information about possible side effects and risks of androstenedione is very limited. Also, recent studies show that the drug's actions don't support manufacturer's claims. While a few individuals have shown increased levels of testosterone, most failed to achieve increases in blood testosterone levels. Initial medical research has raised concerns about this supplement's safety. Doctors worry that androstenedione may increase the risk of heart disease or liver cancer. In addition, research also associates androstenedione use with increases in estradiol, a female estrogen.