A Hitchhiker’s Guide to Marijuana

Facts to Know Before Partaking by Leigh Cooper

With the legalization of both medical and recreational marijuana, it may become more tantalizing to puff on a joint or take a bite of a pot brownie. Whether first-time users or returning enthusiasts, patients in pain or party-goers, potential marijuana consumers can separate marijuana fact from fiction by asking questions about the health risks of using marijuana and the differences among marijuana products.

Is marijuana safe?

Cannabis users, when they’re high, experience euphoria, relaxation and pain relief, but negative side effects such as depression, paranoia and anxiety occasionally occur. Donald Misch, M.D., CU’s senior assistant vice chancellor for health and wellness and director of Wardenburg Health Center, notes, “There also is a significant risk for psychosis for those who either have a personal history of psychosis—they are schizophrenic or psychotic—or have a family history of psychosis.”

Studies show that people under the influence of marijuana have a reduced ability to create new memories, which means students do not learn well while high. Marijuana use also doubles the risk of motor-vehicle accidents. 

“The real issue with marijuana is the age at which you begin using and the frequency,” Misch says. “If you start as an early user and are a chronic, frequent, heavy, daily user, you are at risk for adverse effects.” A properly developing adolescent brain prunes unneeded neural connections and makes important pathways more efficient. Marijuana can impair these processes, resulting in irreversible neurologic deficits in cognition and intelligence. 

This is worrisome because “the more accessible a drug is and the more the perception is that it is not harmful, the more the drug gets used,” says Katie McGee of Boulder County Public Health. BCPH’s data show that the perceived harmfulness of marijuana is decreasing among Boulder County youth.

What happens at a pot store?

Customers will need to choose from a bewildering array of different strains and products. There are two main strains of marijuana, sativa and indica, as well as a cornucopia of hybrids. Daniel Taras, a PR representative from Boulder’s Helping Hands MMJ Dispensary, says sativa is for daytime use and results in high levels of energy and creativity, while indica is often used at night for relaxation and anti-anxiety. 

Consuming marijuana via inhalation is fast-acting, while the onset time for long-lasting edibles, such as brownies or candies, is about 45 minutes, says Brandon Kimpland, a manager at The Farm, a Boulder dispensary. He adds, “The effects are going to be quite variable depending on the person.” 

THC (tetrahydrocannabinol), the primary psychoactive constituent of marijuana, can be extracted from cannabis plants, and these extracts are cooked into edibles, or can be used topically, as with salves. 

A Colorado Medical Marijuana Registration Card, which requires a doctor’s evaluation, is not a prescription for marijuana and does not specify dosages. Instead, dispensaries help customers choose products and dosages that suit their specific needs. Kimpland says, “Everyone should talk to a physician about dosage. We say to start small and work your way up. Find what works for you.” 

According to Colorado state law, dosages must appear on all labels, Taras says. “Generally 5 to 10 milligrams of THC is a good starter dose for someone who wants to feel relaxed and have a nice experience.” 

With new state regulations, labels for all substances soon “will be standardized,” Kimpland says. Labels will note the use of nonorganic pesticides and herbicides during cultivation, as well as mold and microbe contaminants; the results of any tests run on potency; and residual solvents in extracts, such as butane and plastics. 

How much is too much?

Emergency rooms don’t see fatalities with marijuana as they do with other drugs. Timothy Meyers, M.D., an ER physician with Boulder Community Hospital, says he sees people “trying marijuana for the first time and experiencing what most would consider normal side effects of the medicine.”

More dramatic cases do present, sometimes stemming from marijuana contaminants. “If you are seeing your family member or friend behaving in a way that makes you believe they are not safe, that’s the time to call 911. Marijuana by itself doesn’t do that very often, but it can,” says Christopher Colwell, M.D., chief of Emergency Medicine at Denver Health.

Unfortunately, the number of accidental ingestions of marijuana by children has risen since the legalization of medical marijuana, according to Children’s Hospital Colorado. Colwell says, “There are usually no acute medical concerns, although is it not something we want to encourage. There is no way to reverse the effects of marijuana, so we watch the patient.”

As for pets, a study from CSU found that emergency room visits for marijuana-related problems have quadrupled for dogs since 2005. Dogs will eat joints, edibles and marijuana cuttings, which can lead to death in extreme cases. 

“If it is a classic ‘pot dog’ that got into a moderate amount of marijuana, it’s probably going to be fine,” says Sean Williams, D.V.M., of Boulder’s Alpenglow Veterinary Specialty
& Emergency Center. “It does not seem to
take much in terms of exposure, but of the maybe 1,000 cases we’ve seen, I’ve never seen a dog remotely comfortable under the influence of THC.”


Because marijuana ingestion results in similar symptoms as the ingestion of other very dangerous toxins, owners should call their veterinarian right away if their dog is sick. Consumers can protect their pets and children by simply storing marijuana and marijuana products in childproof containers, out of reach. 


A recent doctoral graduate of CU, Leigh Cooper works as a science writer for the Cooperative Institute for Research in Environmental Sciences. She lives in Boulder.