Proline (L-Proline) is one of the twenty amino acids used in living organisms as the building blocks of proteins. Proline is a non-essential amino acid that is synthesized from glutamic acid. It is an essential component of collagen and is important for proper functioning of joints and tendons. Proline is used in pharmaceuticals as an excipient and as an active substance in nutritional supplements. Proline is not commonly used in pharmaceuticals as an excipient. It is approved for use in Privigen (IVIg) and Hizentra (SCIg) solution for injection as a stabiliser for IgG. Proline is also contained in low amounts in several vaccines, e.g. Havrix 720 Kinder (Hepatitis A).

Capric acid (decanoic acid) is a medium-chain fatty acid found in saturated fats (cow butter, and plant oils like coconut oil). Capric acid is a major constituent of the MCT ketogenic diet, providing about 40% of the medium chain fat within the diet. The acid is discussed to have positive effect on seizure control through direct AMPA receptor inhibition and on mitochondrial diseases through the binding to PPARgamma. It readily crosses the blood-brain barrier, probably by a combination of diffusion and saturable carrier-mediated transport via a medium-chain fatty acid transporter.

Ethoxyquin (EQ) has been used as an antioxidant in animal feed for many years, but pharmacological use of EQ has never been evaluated in humans despite that small amounts of EQ exist in certain food items. The level of this antioxidant in animal feeds should not be higher than 150 ppm (U.S. FDA permissions). Ethoxyquin is rapidly absorbed from gastrointestinal tract of laboratory animals like rats and mice. Peak blood concentration of the compound is observed within 1 h. Distribution of EQ in animal body is similar when it is administered orally and intravenously. Small amounts of parent EQ were detected in liver, kidney, and adipose tissue and fish muscles. It is excreted predominantly as metabolites via urine. Ethoxyquin is also registered as an antioxidant to control scald (browning) in apples and pears. EQ-induced DNA damage in human lymphocytes in a dose-dependent manner. According to the studies on dogs and laboratory animals it was shown that ethoxyquin had little acute toxicity, except when it is administered parenterally. Values of LD50 for EQ are 1700 mg kg−1 bw (rats, oral gavage), 2000 mg kg−1 bw (rats, dermal treatment, 24 h), 900 mg kg−1 bw (mice, intraperitoneal administration), and 180 mg kg−1 bw (mice, intravenous administration).

Methyl laurate (methyl dodecanoate), a flavouring agent, is found in alcoholic beverages.

Pentadecalactone is a lactone of 15-hydroxypentadecanoic acid.Pentadecalactone is a perfume and fragrance ingredient added to cosmetics and beauty products. It is known for its sweet, powdery, and woody odor. Pentadecalactone is one of the key phermones produced by the apocrine glands of the male armpit, and is credited with attracting females; it is found in other mammals as well. It is FDA approved for use as an indirect food additive. According to the Cosmetic Database, Pentadecalactone is 77% safe and considered a low hazard ingredient.

Sodium butoxide (Sodium butanolate) is used in wide range of applications in organic synthesis; agrochemicals; pharmaceuticals, colorants and aroma chemicals. It can also be used in manufacturing detergents, as a catalyst in polymerization and isomerizations.

Neotame is a derivative of a dipeptide compound of the amino acids - aspartic acid and phenylalanine. Neotame has been developed as a sweetener with a high degree of sweetness and is obtained by N-alkylating aspartame. Its degree of sweetness varies according to the kind of food and blend composition. It is 7000 to 13,000 times and about 30 to 60 times sweeter than sugar and aspartame respectively. Neotame is rapidly metabolized, completely eliminated and does not accumulate in the body. The major metabolic pathway of neotame is hydrolysis of the methyl ester by esterase which is present throughout the body. This yields de-esterified neotame, the major metabolite and a significant amount of methanol. Due to the presence of the 3-3-di-methylbutyl group, peptidases which would typically break the peptide bond between the aspartic acid and phenylalanine moieties are essentially blocked, thus reducing the availability of phenylalanine. Neotame was approved by the USFDA as a general purpose sweetener in July 2002

Skatole or 3-methylindole is a mildly toxic white crystalline organic compound belonging to the indole family. It is formed in the intestine by the bacterial decomposition of l-tryptophan and found in fecal matter, to which it imparts its characteristic odor. Skatole is a partial AhR agonist. Skatole is used in perfume compositions and in artificial Civet bases.