Terpenes/terpenoids have a wide range of biological and pharmacological activities, for instance, antifungal, antiviral, anticancer, anti-inflammatory, antihyperglycemic, antiparasitic, antioxidant, and antimicrobial. It is not possible to describe all pharmacological effects of terpenes/terpenoids in this paper, but we shall give just some examples for imagination of how important these compounds are in this plant. Monoterpene myrcene is the smallest terpene but the most prevalent terpene found in most varieties of cannabis. Chemotypes high in myrcene will result in a “couch lock” effect (if a sample has over 0.5% myrcene), while chemotypes with low levels of myrcene (<0.5% myrcene) will produce a more energetic high. It is simply the amount of myrcene that is in the sample that dictates how you will be affected. Myrcene is simply the important monoterpene in the plant. Myrcene has antipsychotic, antioxidant, analgesic, anti-inflammatory, sedative, muscle relaxant, and anticancerogenic properties [
53-
56]. The most important sesquiterpene in the cannabis plant is probably β-caryophyllene. It is a spicy terpene. This compound is the only terpene known to interact with the body’s endocannabinoid system (selectively binds to the CB2 receptor) [
57]. Caryophyllene has gastroprotective, analgesic, anticancerogenic, antifungal, antibacterial, antidepressant, anti-inflammatory, antiproliferative, antioxidant, anxiolytic, analgesic, and neuroprotective effects [
58,
59]. The presence of β-caryophyllene in many essential oils might contribute strongly to their antiviral ability. β-Caryophyllene displayed a high selectivity index of 140 against herpes simplex virus type 1 in vitro. The selectivity index was determined by the ratio of the cytotoxic concentration of the drug that reduced viable cell number by 50% to antiviral activity, which inhibited plaque numbers by 50% compared with the untreated control [
60]. α-Pinene (antibacterial, anti-inflammatory, bronchodilator, antiseptic, and gastroprotective) and β-pinene (antiseptic) are the next important compounds [
61]. It is not possible to mention here all the biodynamic terpenes. After all, there may be mentioned, for instance, limonene (antibacterial, gastroprotective, antiproliferative, antifungal, anxiolytic, antidepressant, antimicrobial, antispasmodic, or immunostimulant) [
62,
63]. Linalool (sedative, antipsychotic, anticonvulsant, anxiolytic, anesthetic, antidepressant, analgesic, antiepileptic, and antineoplastic) [
64], terpineol (antioxidant, antibiotic, and relaxing effect) [
65], or caryophyllene oxide (analgesic, anticancer, antifungal, and anti-inflammatory) [
66]. Between others are also phellandrene (antifungal and digestive disorders) [
67], ocimene (antifungal) [
68], camphene (cardiovascular disease) [
69], guaiol (antitumor) [
70,
71], α-humulene (antibacterial, anti-inflammatory, and antitumor) [
72-
74], γ-terpinene (analgesic, anti-inflammatory, antimicrobial, and anticancer) [
75,
76], β-elemene (antitumor, antineoplastic, and anticancer) [
77-
80], nerolidol (antiparasitic and antileishmanial) [
81,
82], or citral (antifungal, antimicrobial, antiproliferative, cytotoxic, anticancer, and antitumor) [
83-
90].