What potential side effect can occur from pre-workout supplements related to skin sensations?

Pre-workout supplements often contain various ingredients designed to enhance energy and performance, such as caffeine, beta-alanine, and niacin. One potential side effect associated with these supplements, specifically from components like niacin, is itching. Niacin can cause a flushing reaction, which often manifests as itching and a feeling of warmth or burning in the skin, particularly in the face and other areas where blood vessels are more superficial. This reaction is known as "niacin flush" and occurs due to the dilation of blood vessels.

Other options, while they may be related to skin sensations, do not directly correlate with the common side effects of pre-workout supplements as closely as itching does. For example, redness can occur, but it is typically part of the flushing response rather than a separate side effect. Aging and puffiness are less directly connected to the immediate effects of pre-workout ingredients. Understanding these specific side effects helps individuals make informed decisions about their supplement use and potential reactions they might experience during workouts.