Phenylacetic acid (abr. PAA and synonyms are: α-toluic acid, benzeneacetic acid, alpha tolylic acid, 2-phenylacetic acid, β-phenylacetic acid) is an organic compound containing a phenyl functional group and acarboxylic acid functional group. Because it is used in the illicit production of phenylacetone (used in the manufacture of substituted amphetamines), it is subject to controls in countries including the United States and China Phenylacetic acid is used in some perfumes, possessing a honey-like odor in low concentrations, and is also used in penicillin G production. It is also employed to treat type II hyperammonemia to help reduce the amounts of ammonia in a patient's bloodstream by forming phenylacetyl-CoA, which then reacts with nitrogen-rich glutamine to form phenylacetylglutamine. This compound is then secreted by the patient's body. In Phase 2 of clinical research it investigated in the treatment of Brain and Central Nervous System Tumors.

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.

Hydroxyamphetamine is a derivative of amphetamines. Hydroxyamphetamine is intended mainly as local eye drops for diagnostic purposes. It is indirect sympathomimetic agent which cause dilation of the eye pupil before diagnostic test. Among the minor side effects from its use are: change in color vision, difficulty seeing at night, dry mouth, headache, increased sensitivity of eyes to sunlight, muscle stiffness or tightness and temporary stinging in the eyes. The main use of hydroxyamphetamines as eye drops is the diagnosis of Horner's syndrome which is characterized by nerve lesions. Hydroxyamphetamine hydrobromide is a component of FDA approved brand drug - Paremyd sterile ophthalmic solution (Hydroxyamphetamine hydrobromide, USP 1.0%, Tropicamide, USP 0.25%). Hydroxyamphetamine is an indirect-acting sympathomimetic, while tropicamide acts as a parasympatholytic.

Hippuric Acid is an acyl glycine produced by the conjugation of benzoic acid and glycine, found as a normal component in urine as a metabolite of aromatic compounds from food. Increased urine hippuric acid content may have antibacterial effects. Hippuric Acid is used therapeutically in the form of its salts (hippurates of calcium and ammonium). It is an ingredient of FDA-approved drug Hiprex (methenamine hippurate tablets USP). Each yellow capsule-shaped tablet of Hiprex contains 1 g Methenamine Hippurate which is the Hippuric Acid Salt of Methenamine (hexamethylene tetramine). The tablet also contains inactive ingredients. Hiprex (methenamine hippurate tablets USP) has antibacterial activity because the methenamine component is hydrolyzed to formaldehyde in acid urine. Hippuric acid has some antibacterial activity and also acts to keep the urine acid. The drug is generally active against E. coli, enterococci and staphylococci. Enterobacter aerogenes is generally resistant. The urine must be kept sufficiently acid for urea-splitting organisms such as Proteus and Pseudomonas to be inhibited. Hiprex is indicated for prophylactic or suppressive treatment of frequently recurring urinary tract infections when long-term therapy is considered necessary.

Amphetamine is also prescribed in enantiopure and prodrug form as dextroamphetamine and lisdexamfetamine respectively. Lisdexamfetamine is structurally different from amphetamine, and is inactive until it metabolizes into dextroamphetamine. Dextroamphetamine is useful for those with ADHD and Narcolepsy. It improves self-control for people who have a hard time naturally controlling themselves. Dextroamphetamine aids a person learning and memory of words, and perhaps makes the brain stronger. When a person given dextroamphetamine is tested, their brain is extremely active in the brain parts required for the test and radically less active in other parts. Short practice sessions with dextroamphetamine have a greater effect on learning than sessions without dextroamphetamine. Dextroamphetamine raises decision-making scores, improves choices, and changes beliefs about rewards; at the same time, dextroamphetamine barely—if at all—affects guesses of time. Those who feel lower amounts of joy from dextroamphetamine have greater impulsivity improvements compared to those who feel extreme happiness. The drug should be avoided for those who have hypersensitivity to amphetamines, a history of drug abuse, cardiovascular diseases, hypertensive disease, hyperthyroidism, or in those with glaucoma. In 1935, the medical community became aware of the stimulant properties of amphetamine, specifically dextroamphetamine, and in 1937 Smith, Kline, and French introduced Dexedrine tablets, under the tradename Dexedrine. In the United States, Dexedrine tablets were approved to treat narcolepsy, attention disorders, depression, and obesity. Dexedrine, along with other sympathomimetic, was eventually classified as schedule II, the most restrictive category possible for a drug with recognized medical uses. The exact mechanism of action is not known. Dextroamphetamine stimulates the release of norepinephrine from central adrenergic receptors. At higher dosages, it causes release of dopamine from the mesocorticolimbic system and the nigrostriatal dopamine systems by reversal of the monoamine transporters. Dextroamphetamine may also act as a direct agonist on central 5-HT receptors and may inhibit monoamine oxidase (MAO). Modulation of serotonergic pathways may contribute to the calming effect.

Amphetamine is also prescribed in enantiopure and prodrug form as dextroamphetamine and lisdexamfetamine respectively. Lisdexamfetamine is structurally different from amphetamine, and is inactive until it metabolizes into dextroamphetamine. Dextroamphetamine is useful for those with ADHD and Narcolepsy. It improves self-control for people who have a hard time naturally controlling themselves. Dextroamphetamine aids a person learning and memory of words, and perhaps makes the brain stronger. When a person given dextroamphetamine is tested, their brain is extremely active in the brain parts required for the test and radically less active in other parts. Short practice sessions with dextroamphetamine have a greater effect on learning than sessions without dextroamphetamine. Dextroamphetamine raises decision-making scores, improves choices, and changes beliefs about rewards; at the same time, dextroamphetamine barely—if at all—affects guesses of time. Those who feel lower amounts of joy from dextroamphetamine have greater impulsivity improvements compared to those who feel extreme happiness. The drug should be avoided for those who have hypersensitivity to amphetamines, a history of drug abuse, cardiovascular diseases, hypertensive disease, hyperthyroidism, or in those with glaucoma. In 1935, the medical community became aware of the stimulant properties of amphetamine, specifically dextroamphetamine, and in 1937 Smith, Kline, and French introduced Dexedrine tablets, under the tradename Dexedrine. In the United States, Dexedrine tablets were approved to treat narcolepsy, attention disorders, depression, and obesity. Dexedrine, along with other sympathomimetic, was eventually classified as schedule II, the most restrictive category possible for a drug with recognized medical uses. The exact mechanism of action is not known. Dextroamphetamine stimulates the release of norepinephrine from central adrenergic receptors. At higher dosages, it causes release of dopamine from the mesocorticolimbic system and the nigrostriatal dopamine systems by reversal of the monoamine transporters. Dextroamphetamine may also act as a direct agonist on central 5-HT receptors and may inhibit monoamine oxidase (MAO). Modulation of serotonergic pathways may contribute to the calming effect.

Amphetamine is also prescribed in enantiopure and prodrug form as dextroamphetamine and lisdexamfetamine respectively. Lisdexamfetamine is structurally different from amphetamine, and is inactive until it metabolizes into dextroamphetamine. Dextroamphetamine is useful for those with ADHD and Narcolepsy. It improves self-control for people who have a hard time naturally controlling themselves. Dextroamphetamine aids a person learning and memory of words, and perhaps makes the brain stronger. When a person given dextroamphetamine is tested, their brain is extremely active in the brain parts required for the test and radically less active in other parts. Short practice sessions with dextroamphetamine have a greater effect on learning than sessions without dextroamphetamine. Dextroamphetamine raises decision-making scores, improves choices, and changes beliefs about rewards; at the same time, dextroamphetamine barely—if at all—affects guesses of time. Those who feel lower amounts of joy from dextroamphetamine have greater impulsivity improvements compared to those who feel extreme happiness. The drug should be avoided for those who have hypersensitivity to amphetamines, a history of drug abuse, cardiovascular diseases, hypertensive disease, hyperthyroidism, or in those with glaucoma. In 1935, the medical community became aware of the stimulant properties of amphetamine, specifically dextroamphetamine, and in 1937 Smith, Kline, and French introduced Dexedrine tablets, under the tradename Dexedrine. In the United States, Dexedrine tablets were approved to treat narcolepsy, attention disorders, depression, and obesity. Dexedrine, along with other sympathomimetic, was eventually classified as schedule II, the most restrictive category possible for a drug with recognized medical uses. The exact mechanism of action is not known. Dextroamphetamine stimulates the release of norepinephrine from central adrenergic receptors. At higher dosages, it causes release of dopamine from the mesocorticolimbic system and the nigrostriatal dopamine systems by reversal of the monoamine transporters. Dextroamphetamine may also act as a direct agonist on central 5-HT receptors and may inhibit monoamine oxidase (MAO). Modulation of serotonergic pathways may contribute to the calming effect.