In 1943, Albert Hofmann reported perceiving "an uninterrupted stream of fantastic pictures, extraordinary shapes with intense, kaleidoscopic play of colors." Hofmann, a chemist, created- and on one Friday afternoon in April 1943 accidentally ingested- LSD (lysergic acid diethyl amide). The result reminded him of a childhood mystical experience that has left him yearning for another glimpse of a "miraculous, powerful, unfathomable reality." LSD, a synthetic hallucinogen, unlocks serotonin channels that normally filter sensory experiences and therefore causes sensory overload.
I found this article that describes the effects of LSD. It's definitely interesting.
It's often said that LSD causes hallucinations, but LSD really changes the way people perceive the world surrounding them, as well as what they think and feel. People on LSD see what's actually in front of them in an different way, and most of the time, are aware that their perceptions have been altered by the drug.
After taking LSD, the effects, known as a "trip," typically start within an hour and can last up to 12 hours, with a peak about halfway through. LSD can affect each person differently. Some physical changes in the body during "tripping" include dilated pupils, increased blood pressure and a high body temperature. People on LSD may also feel dizzy, sweat, have distorted vision and feel tingling in their hands and feet. They may feel drowsy but not sleepy.
LSD's major effects are visual. Colors seem more intense and lights seem brighter. Objects that are stagnant might appear to move or have a halo of light around them. Sometimes objects have trails of light coming from them or appear smaller or larger than they actually are. LSD users often see patterns, shapes, colors and textures. Sometimes it seems that time is running backward, or moving very quickly or slowly. On very rare occasions (although it's sometimes portrayed as common), tripping can cause synesthesia. Some people have described this as seeing colors when they hear specific sounds.
There is an overall sense of happiness and elation. Everything is delightful, wonderful, and magical, filled with unicorns and rainbows. People on LSD often become very emotional and dreamlike. Large doses of LSD make them feel especially pensive. They feel that their mind has burst through the limits of normal boundaries, and they often declare to have had experiences that are spiritual or religious, with a new understanding of how the world works.
People tripping on LSD are generally impulsive and have very poor judgment. This is part of the reason why LSD users prefer to trip in groups, especially with others who have experience, and in serene places like at home or in a park. For people not tripping but are merely spectating, LSD users can be frightening. They might spend lots of time contemplating something that appears incredibly unimportant. They aren't always easy to understand, but when they do talk, they speak quickly and jump from subject to subject.
What I mentioned above are considered to be "good trips." Most people who have used LSD know that there's always a looming possibility of having a "bad trip." It's not really clear what causes a bad trip, especially since each trip can vary depending on the person. LSD users sometimes say that it's due to the "set and setting." This means that if the user is already in a bad mood, or if the trip is in a structured environment that requires him/her to think logically (such as school), the user could have a bad trip. This may include losing sight of the delusory aspect of tripping, which results in fear and paranoia. The loss of control is terrifying, and it seems like the trip will never end. Sometimes when someone has a bad trip, he or she is taken to a hospital. However, there typically isn't much that doctors can do other than give the person a quiet space and reassurance. They may administer an anti-anxiety medication or a mild tranquilizer to ease the patient's trepidation. As the trip ends, the patient may feel dizzy or nauseous, but people usually recover with no lasting side effects.
For some, one bad trip is enough to swear off LSD forever. Even if LSD users don't have a bad trip, heavy use of LSD can still cause a lot of problems. One of the largest issues are its possible lingering effects, which can cause a reaction to the drug randomly again in the future. This suggests that the brain holds and may release molecules of LSD over time, and some believe that this is what causes "flashbacks." A flashback occurs when a person who has used LSD in the past has an experience, lasting anywhere from seconds to hours, similar to that of an actual trip. Some LSD users enjoy them and regard them as "free trips," while others find them incredibly disturbing. The majority of LSD users report never having flashbacks, and some people claim that they don't really exist.
Any who, for your convenience I have attached a picture of what a "trip" of LSD may look like.
Super trippy (no pun intended), right?
Source: http://science.howstuffworks.com/lsd3.htm