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  1. Physical
  2. Psychological
  3. Sensory


  • Pupil dilation, reduced appetite, and wakefulness are the three main physical side effects of LSD.

Other physical reactions to LSD are highly variable and nonspecific, some of which may be secondary to the psychological effects of LSD.

These physical side effects include:

  • Numbness
  • Weakness
  • Nausea
  • Hypothermia or Hyperthermia
  • Elevated Blood Sugar
  • Goose Bumps
  • Heart rate increase
  • Jaw clenching
  • Perspiration
  • Saliva Production
  • Mucus Production
  • Hyperreflexia
  • Tremors

Many of these variable side effects depend on dose size and Set and Setting. Also, many of them do not affect a trip as one would expect. Instead, they are secondary to the overwhelming psychological effects present in an LSD trip.



So, what are the main psychological effects of LSD?

I split the psychological effects into three main camps: positive, neutral, and negative. At low to moderate dose amounts, the positive and neutral effects predominate. However, as the dose size increases, negative psychological effects begin to increase.


  • Increase in associative and creative thinking
  • Closed and open-eye visuals
  • Ego dissolution
  • Sense of unity and connectedness to other life forms
  • General sense of euphoria
  • Life-changing spiritual experiences


  • Change in consciousness
  • Lost track of time
  • Lack of focus
  • Unusual thoughts and speech
  • Range of emotions

Negative (many of these are associated with a ‘bad trip’):

  • Paranoia
  • Anxiety
  • Fear of death
  • Overwhelming feelings
  • Flashbacks


One of the primary effects of LSD is an increase in sensory perception. Users report an enhanced appreciation for music, reporting that they ‘heard’ music for the first time. Others report a sharper sense of smell and more developed sense of taste.

Touch becomes a necessity when on LSD. Users experience a strong desire to touch soft items as well as other human beings.

One unique property of both LSD and other psychedelics is synesthesia. Synesthesia is when users associate different feelings with each other. For example, a user might hear music and feel like he or she can ‘hold’ the music. Other users might ‘taste’ the music. More on synesthesia here

These are the primary LSD effects.

If you know of any others, please leave a comment below!

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