While cannabis in general is very safe, you may experience one or more of the following effects, some of which may feel unpleasant or unfamiliar to you.These effects are primarily caused by THC (not CBD), and are intensified by higher doses of THC. Note that these effects will dissipate with time as your medication wears off.
- Red eyes (very common)
- Dry mouth (very common)
- Feeling high (euphoria)
- Sense of well-being
- Heightened senses (sight, sound, taste, smell)
Adverse effects can include:
- Impaired ability to concentrate, remember, react quickly, or pay attention
- Anxiety, fear or panic
- Decreased blood pressure, possibly leading to fainting
- Increased heart rate
- Paranoia, delusions and/or hallucinations
CBD is generally safe and well-tolerated, however people may experience dry mouth, diarrhea, and/or drowsiness, usually at relatively high doses. The effects wear off within hours.
There is a rare disorder called cannabinoid hyperemesis syndrome (CHS) that is marked by severe bouts of nausea and vomiting. This disorder arises in some people who have been taking very large amounts of cannabis over a long period of time. Conventional anti-nausea drugs aren't helpful for CHS suffers, but the disorder typically resolves by abstaining and taking hot baths. Here is an article that goes into detail on CHS.
Cannabis can also aggravate certain underlying medical conditions, such as schizophrenia. Your doctor will have assessed your risk of any serious adverse affects prior to prescribing cannabis to you.