Valeric acid, or pentanoic acid, is a straight-chain alkyl carboxylic acid

Carboxylic acid

Carboxylic acids are organic acids characterized by the presence of at least one carboxyl group. The general formula of a carboxylic acid is R-COOH, where R is some monovalent functional group...

 with the chemical formula

Chemical formula

A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....

 C₅H₁₀O₂. Like other low-molecular-weight carboxylic acids, it has a very unpleasant odor. It is found naturally in the perennial flowering plant valerian

Valerian (herb)

Valerian is a hardy perennial flowering plant, with heads of sweetly scented pink or white flowers which bloom in the summer months. Valerian flower extracts were used as a perfume in the sixteenth century....

 (Valeriana officinalis), from which it gets its name. Its primary use is in the synthesis of its ester

Ester

Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...

s. Volatile esters of valeric acid tend to have pleasant odors and are used in perfumes and cosmetics. Ethyl valerate and pentyl valerate

Pentyl pentanoate

Pentyl pentanoate is an ester used in dilute solution to replicate the scent or flavour of apple, and sometimes pineapple. It is referred to as pentyl valerate or amyl pentanoate using classical nomenclature....

 are used as food additives because of their fruity flavors.

Valeric acid has a similar structure to both GHB

Gamma-Hydroxybutyric acid

γ-Hydroxybutyric acid , also known as 4-hydroxybutanoic acid and sodium oxybate when used for medicinal purposes, is a naturally occurring substance found in the central nervous system, wine, beef, small citrus fruits, and almost all animals in small amounts. It is also categorized as an illegal...

 and the neurotransmitter GABA

Gamma-aminobutyric acid

γ-Aminobutyric acid is the chief inhibitory neurotransmitter in the mammalian central nervous system. It plays a role in regulating neuronal excitability throughout the nervous system...

. It differs from valproic acid

Valproic acid

Valproic acid is a chemical compound that has found clinical use as an anticonvulsant and mood-stabilizing drug, primarily in the treatment of epilepsy, bipolar disorder, and, less commonly, major depression. It is also used to treat migraine headaches and schizophrenia...

simply by lacking a 3-carbon side-chain.

Safety

Valeric acid can cause irritation if it comes into contact with the skin, eyes, or mucous membranes, but otherwise causes little harm because it tends not to vaporize at room temperature unless it is in its pure glacial form. It is, however, toxic to aquatic life and so should not be disposed of into drains without first diluting the acidic solution.