Is potassium alum safe to apply anally as an astringent?
According to the FDA and general applications, it should not be harmful. The inability to observe any changes may make proper dosage difficult to determine. Applying any chemical to body parts is really a question that should be discussed with a physician rather than a chemist. It is "Generally Recognized As Safe" by the FDA and is used in deoderants. It is an astringent as well.
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