A suppository is a medicine that is inserted either into the rectum (rectal suppository) or into the vagina (vaginal suppository) where it melts.

Vaginal suppositories are used to treat gynaecological ailments, especially vaginal infections such as candidiasis. They may also be applied prior to sexual intercourse for local contraceptive purposes, as well as for vaginal lubrication.

Rectal suppositories are used:

• For laxative purposes, with chemicals such as glycerin or bisacodyl ;
• To treat a hemorrhoid by delivering a moistureizer or vasodilator;
• For general medical administration purposes: the substance crosses the rectal mucosa into the bloodstream; examples include paracetamol and eucalyptol suppositories.

Except for glycerin suppositories, suppositories are made of a greasy excipient (formerly, cocoa butter) in which the active substance is diluted. This may be a source of discomfort for the patient, as the melted excipient may pass the anus during flatulences.

Suppositories are used especially for small child patients, for they may be easier to administer than tablets or syrups.