CBD (Cannabidiol) and THC (Tetrahydrocannabinol) are two primary compounds found in the cannabis plant, both belonging to the cannabinoid family, but they have different chemical structures and physiological effects. Here are the main differences:

 1. Chemical Structure and Source

   - CBD: CBD is a non-psychoactive compound found in the cannabis plant, primarily extracted from industrial hemp. Industrial hemp contains high levels of CBD and very low levels of THC.

   - THC: THC is the main psychoactive compound in cannabis, typically extracted from the flowers of the cannabis plant. THC directly interacts with the brain's CB1 receptors, producing the "high" feeling.

 2. Psychotropic Effects

   - CBD: CBD does not have psychoactive effects, meaning it does not cause a "high" or intoxication. Instead, CBD is typically known for its calming and relaxing effects, often helping to reduce anxiety and stress.

   - THC: THC is psychoactive and stimulates the CB1 receptors in the brain, producing a "high" feeling. THC can affect mood, sensory perception, memory, and cognitive functions, sometimes causing euphoria, relaxation, or anxiety.

 3. Medical Applications

   - CBD: Research on CBD focuses on its anti-inflammatory, anti-anxiety, analgesic, anticonvulsant, antioxidant, and antipsychotic properties. It is widely used to treat conditions such as anxiety disorders, insomnia, epilepsy, and chronic pain. It is also used to alleviate side effects of cancer treatments, such as nausea and loss of appetite.

   - THC: THC also has medical applications, mainly for pain relief, appetite stimulation, and alleviating nausea and vomiting (especially in chemotherapy patients). THC is also used to relieve symptoms in conditions like multiple sclerosis and AIDS.

 4. Side Effects

   - CBD: CBD is generally considered safe, with few side effects. Occasionally, it may cause fatigue, changes in appetite, or gastrointestinal discomfort. CBD is not addictive or habit-forming.

   - THC: THC has more side effects, including anxiety, paranoia, memory impairment, dry mouth, and red eyes. Long-term use can lead to dependence, especially with high doses of THC. Due to its psychoactive nature, it can impair driving and other activities requiring focus.

 5. Legal Status

   - CBD: In many countries and regions, CBD products are legal as long as the THC content is below a specific limit (e.g., in the US, CBD must contain no more than 0.3% THC). Because CBD is non-psychoactive, its legal regulation is generally more lenient.

   - THC: THC is more strictly regulated. In many countries and regions, cannabis products with high THC content are still illegal, although some areas have legalized medical or recreational cannabis.

 6. Mechanisms of Action

   - CBD: CBD primarily interacts with CB2 receptors (related to the immune system) in the brain and body, affecting immune function and inflammation. It also interacts with other pathways, including the 5-HT1A receptors (related to mood and anxiety), which contributes to its anti-anxiety and calming effects.

   - THC: THC primarily interacts with CB1 receptors in the brain, which are involved in regulating sensory experiences, mood, memory, appetite, and cognition. This interaction is responsible for THC's psychoactive effects, such as euphoria and altered perception.

 7. Drug Testing

   - CBD: Routine drug tests typically do not screen for CBD, as it is not psychoactive. However, if a CBD product contains trace amounts of THC, it might show up on a drug test.

   - THC: THC is commonly tested for in drug tests, especially for drug abuse screening. THC can be detected in blood, urine, or saliva samples.

 Summary:

- CBD: Non-psychoactive, with a wide range of medical applications, generally safe, and often used for relieving anxiety, pain, and inflammation.

- THC: Psychoactive, causing a "high" feeling, primarily used for pain relief, appetite stimulation, and alleviating nausea, but it can have side effects and carries a risk of dependence.

When choosing between CBD or THC products, consumers should make informed decisions based on personal health needs, legal considerations, and specific requirements. If used for medical purposes, it is advisable to consult with a healthcare professional.