Combusting marijuana (past a certain temperature) may produce a range of toxic and/or cancer-causing compounds including but not limited to: benzene and methacrolein.
Although some studies have actually shown various degrees of respiratory relief (especially when vaporizing vs. combusting) there is some risk of respiratory complications. Some of these complications include (but are not limited to): bronchitis, COPD, emphysema, and others.
Depending on preparation, “edibles” which are made with cannabis flower may contain a high amount of chlorophyll; which can cause indigestion and/or constipation for some who are not used to eating a large amount of green vegetables.
Specific combinations of cannabinoids may cause various psychoses such as anxiety and/or paranoia in some users in certain situations. Other times these users may experience none of these symptoms. These particular risks seem to be correlated with swings in blood sugar levels, interestingly enough. Besides low blood sugar, anxiety and paranoia may be brought on by certain imbalances of cannabinoids. An unfavorable balance may produce an unfavorable “entourage effect”. High levels of THC and/or CBD without proper levels of their counterpart cannabinoids (such as CBD, CBN, terpnes such as linalool, limonene, alpha-pinene, etc.) can contribute significantly to negative or insecure feelings such as anxiety and paranoia. This is one major reason why most people do not prefer the current synthetic forms of cannabis over the “real thing”. It may not be much of a surprise; but the user’s mental disposition at a certain time can also be a big factor.
Other mental risks may include forms of ADD, low productivity, and other mental issues such as short term memory loss (or not).
Certain growing and/or processing practices may also pose minor or major health risks. The unrestrained use of dangerous pesticides can be a minor or major health risk. Fungal by-products and insect fecal matter may be left in the buds when grown improperly; which pose less dangerous risk factors but are nevertheless important to consider. Incorrect treatment/storage of flower after harvest may encourage fungus to grow and produce more of these byproducts then necessary — leaving residual compounds in the flower. This is why it’s important to buy from a reputable dispensary who vets each of their growers and works with only the best!
Left over solvents from improper or hasty purging of extracts/concentrates could result in the final product containing some of these chemicals. Any pesticides used during the grow could end up extracted and therefore concentrated in the final product if not careful with processing the cannabis correctly.
Synthetic cannabis is basically made up of cannabinoid wannabes that bind to the same receptors in the brain that their natural counterparts would bind to. They are widely regarded as inferior products — except for some brainwashed medical “professionals” and big pharma shills. It’s basically a way for them to actually profit on a plant that is much cheaper to grow the good ‘ol fashioned way!