Which administration method is considered the least invasive for medication?

The sublingual administration method is considered the least invasive for medication because it involves placing the medication under the tongue, allowing it to dissolve and be absorbed directly into the bloodstream through the tissues in the mouth. This technique bypasses first-pass metabolism in the liver and does not require the use of needles, making it a non-invasive option compared to other methods.

In contrast, oral administration requires swallowing the medication, which can be less efficient due to digestion and absorption processes in the gastrointestinal tract. Topical administration typically involves applying medication to the skin, which can be considered more invasive than sublingual as it might lead to skin irritation or absorption issues. Intravenous administration, on the other hand, is the most invasive method as it involves directly injecting medication into the bloodstream via a vein, requiring needle use and posing higher risks of infection or complications. Therefore, sublingual administration stands out as the least invasive route for delivering medication.