Tinctures are often made of a combination of
ethyl alcohol and water as solvents, each dissolving constituents the other is unable to, or weaker at. Varying their proportions can also produce different levels of constituents in the final extraction. As an
antimicrobial, alcohol also acts as a preservative. A downside of using alcohol as a solvent is that ethanol has a tendency to
denature some organic compounds, reducing or destroying their effectiveness. This tendency can also have undesirable effects when extracting botanical constituents, such as
polysaccharides. Certain other constituents, common among them
proteins, can become irreversibly denatured, or "pickled" by the alcohol. Alcohol can also have damaging effects on some aromatic compounds. Ether and
propylene glycol based tinctures are not suitable for internal consumption, although they are used in preparations for external use, such as personal care creams and
ointments. ==Examples==