What is a common effect of hallucinogenic drugs such as LSD?

Hallucinogenic drugs like LSD are known to cause various physiological and psychological effects, one of which is elevated heart rate. This occurs as these substances interact with the serotonin receptors in the brain, which can lead to increased stimulation of the central nervous system. As a result, this heightened activity often manifests as changes in vital signs, including an increase in heart rate.

In contrast, increased pain tolerance typically occurs with certain opioids rather than hallucinogens. Reduced appetite can be associated with many drugs, but hallucinogens are more commonly linked to altered sensory perceptions and emotional states rather than direct appetite suppression. Improved concentration is generally not a recognized effect of hallucinogens; instead, users often experience altered perceptions and distraction, making it difficult to focus. Thus, the most significant and common physiological effect relevant to hallucinogens is indeed an elevated heart rate.