Use the common name: PubMed is not primarily a resource for chemical information, so forget what I said in my column about not searching by name. Enter the common name for a chemical, drug or other substance in the main search box.  Scroll down the results page to the ‘Search Details’ box in the right-hand column to check to see if the name you entered matched a MeSH term.

Use the standardized name: To search by standardized name in PubMed, replace any brackets or parentheses with a hyphen (if not already present). You can either spell out or enter the symbol for Greek characters such as β.

To search for: 1-[(3,5-dichloro)-2,6-dihydroxy-4-methoxyphenyl]-1-hexanone

Enter: 1-3,5-dichloro-2,6-dihydroxy-4-methoxyphenyl-1-hexanone

Search the MeSH database: Didn’t find what you were looking for when you searched by name? Try searching the MeSH database.  Select ‘MeSH’ from the dropdown menu to the left of the main search box.  Enter a component of the name.

To search for: alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid

Enter: isoxazolepropionic

Try a unique identifier: In either PubMed or the MeSH database, enter the CAS RN or FDA Unique Ingredient Identifier (UNII, identifier assigned by the FDA Substance Registration System to substances in drugs, biologics, foods and devices) for a substance. If searching PubMed, then enter the identification number, followed by the field tag ‘[RN]’.  For example: 69-93-2[RN].  I find this method of limited utility, partly because CAS RNs have not been added to MeSH since 1998.