What is a defining feature of a tincture?

A tincture is defined as a very potent solution of active medicinal substances typically extracted using alcohol as a solvent. The use of alcohol allows for the extraction of both water-soluble and alcohol-soluble properties of the medicinal herbs or compounds, resulting in a concentrated form that can be effective in smaller doses. Tinctures are generally taken in drop form and are known for their longer shelf life compared to other forms of herbal medicines, due to the preserving properties of alcohol.

In contrast, the other options do not accurately describe a tincture. Solutions made solely with water do not encompass the unique properties provided by alcohol. A thick paste for topical use refers to a different type of medication formulation, such as an ointment or cream, which serves a different purpose than a tincture. Lastly, a syrup with added sugars typically refers to a sweetened liquid medication for oral administration, lacking the concentrated medicinal effect characteristic of tinctures. Thus, the defining feature of a tincture is its combination of alcohol and active medicine, creating a potent solution.