Stories of people who accidentally ingest too high a dose from pot brownies are funny when they're happening to others, but not when they're happening to you. How do you avoid becoming a cannabis "cookie casualty" like Maureen Dowd?

Understand that cannabis is a psychoactive drug. Develop a basic understanding how cannabis works. Determine the dose of cannabis that will produce the desired outcome, whether medicinally or recreationally. Just because cannabis overdose doesn't kill people, does not mean it can be consumed without reasonable attention to dose. An oral cannabis overdose can be terrifying. Lack of understanding about how cannabis works and not paying attention to dose (clearly printed on the labels of Colorado edibles such as Dowd consumed) made Maureen Dowd's experience with cannabis edibles unpleasant. Many side effects from cannabis are dose-dependent.

How is cannabis a drug?

Cannabis produces over 770 chemical compounds, 90 percent of them in trace amounts. The primary active compounds in cannabis are the cannabinoids and include THC, CBD and CBG. Only THC is psychoactive, but both CBD and CBG possess potent medicinal activity and modify the effects of THC. The other primary effects of cannabis are produced by cannabis's essential oils, a common class of plant chemicals called terpenes. Terpenes can be absorbed orally through the mucous membranes of the mouth, but do not survive digestion if chewed up and swallowed. Myrcene, one of these terpenes (also produced by thyme and lemongrass), is thought to interact with THC and produce the sedative indica effect of smoked or vaporized cannabis varieties. Other terpenes such as beta-caryophyllene and pinene may contribute to the stimulating sativa effect of other cannabis varieties when inhaled. However, when cannabis medicines are swallowed, they do not exhibit these sativa or indica effects.

How does cannabis affect our bodies and brains?

We still learning how cannabis works, though that understanding is improving rapidly. In the late Eighties, the body's endocannabinoid system was discovered, with which cannabis interacts. The endocannabinoid system is a regulatory mechanism that modulates the release of compounds produced throughout the body. As biomolecular chemist Vincenzo Di Marzo has written, the endocannabinoid system's role balances how we relax, eat, sleep, forget and protect. Providing this balance and modulation of signaling throughout the body, the endocannabinoid system is sensitive to doses of the compounds found in cannabis that mimic the body's own endocannabinoids. Endocannabinoids in the brain interact with endocannabinoid protein receptors to regulate and modulate the release of neurotransmitters between neurons. The system reacts to repeated high doses of cannabis by reducing the density of the receptors with which cannabinoids interact, a process called down regulation. As the size and frequency of cannabis dose increases, the density of endocannabinoid receptor targets decreases. This tolerance to the effects of cannabis is why the same dose that a heavy cannabis user consumes easily overwhelms a newbie. Again, it's all about dose. If you want to avoid down-regulation, control your dose.

What is the difference between vaping, smoking, and consuming cannabis orally through edibles or tinctures?

The tradition of consuming cannabis orally is ancient, perhaps ten thousand years old, while cannabis smoking is much more recent. There are scattered references to inhaling cannabis smoke in ancient times, but cannabis was not commonly smoked before the 16th century.

When cannabis is smoked or vaporized, its delta-9-THC is absorbed through the lungs and reaches the brain quickly. When cannabis edibles are swallowed, the delta-9-THC undergoes a transformation within the liver into 11-hydroxy-THC, a different drug twice as strong that lasts twice as long as inhaled delta-9-THC. Oral absorption and liver metabolism of cannabis take much, much longer than when it is smoked. Maureen Dowd didn't feel the effects of the edible she ate for almost an hour, so she took more… a common and unfortunate error. There is wide variation among individuals in how quickly they will perceive the effects of oral cannabis, with some individuals taking over three hours to note effects.

It's important for individuals to develop an idea of how they personally metabolize any oral cannabis preparation, starting with a very small dose and remaining patient until it's thoroughly metabolized over six hours, before taking more. There will be some variation in cannabis absorption through the digestive tract depending on stomach contents and its composition.

The pot available in dispensaries today is radically different than what our parents or grandparents might have toked. How has marijuana changed over the years, and how do the genetic changes in the plant influence dosage and how the drug affects us?

Ultra-high THC potency cannabis is relatively recent. For most of our twelve thousand year history with cannabis, cultivated cannabis drug varieties produced only two or three percent THC. The legendary Thai Stick variety contained around eight percent. Even cannabis resin, hashish, rarely topped twenty percent THC. But prohibition encourages potency and an aggressive drug war encouraged it more. Potent plants require less space, which aids their concealment.

After a thirty-five year War on Drugs, cannabis can exceed twenty-five percent THC. Cannabis resin often exceeds fifty percent, and cannabis oils can top seventy percent THC. Increased potency is not really the issue that prohibitionists claim; but it does reduce the margin of error when consuming cannabis. Like beer vs. whiskey doses, only a fool would pour and consume a pint of whiskey, because most drinkers learn to dose alcohol. Similarly, cannabis users learn that higher-potency cannabis reduces the amount required. But individuals only having experience with the low-potency cannabis of the Seventies and Eighties can be unpleasantly overwhelmed when consuming today's cannabis.

The chemical balance of cannabis has changed since the Sixties. Cannabis breeders for the past forty years have selected plants that produced the highest levels of THC. Unbeknownst to them, many of the early cannabis varieties contained significant levels of CBD as well as THC. CBD is a cannabinoid that is not psychoactive but medicinally valuable and CBD reduces many of the adverse effects produced by THC. Today's cannabis produces THC, and rarely any CBD. Recently, varieties producing CBD have become more available thanks to the testing labs searching for CBD cannabis varieties and organizations such as Project CBD.

How do you determine what a proper dose of herbal cannabis or infused edible is, and what's the science behind cannabis dosage?

Research on dosing herbal cannabis has been hampered by federal law. What is known about herbal cannabis dose is primarily based on anecdote, hundreds of thousands of them, with some extrapolation from doses of prescription cannabis medicines such as Marinol and Sativex. Despite the volume of experience, anecdotal guidance barely suffices. With less prohibition and more research, we would be much more precise in understanding the use of herbal cannabis.

Too many people calculate a dose of cannabis by the amount of THC psychoactivity they can comfortably withstand. A more informed approach to cannabis dose is to determine the minimum dose needed to reach the desired outcome. This minimum dose approach can be challenging when today's herbal cannabis can average 15 percent THC in dispensaries in California,

Cannabis users in the Sixties often consumed an entire joint. Back in the day, a one-gram joint of 2% THC cannabis typically contained about twenty milligrams of THC. A person smoking that joint would absorb around seven milligrams of THC, the rest lost to combustion and sidestream smoke.

By comparison, that one-gram joint filled with a contemporary high-THC variety like OG Kush could contain 250 milligrams of THC. A single 50 milligram inhalation of high-potency cannabis oil (a "dab") can deliver a dose equal to over four joints of Mexican commercial weed from the Seventies.

Remember that the THC in orally consumed cannabis will be metabolized by the liver into 11-hydroxy-THC and this form is twice as strong and will last twice as long as regular THC.

The threshold of THC psychoactivity for most people when consumed orally beneath the tongue or swallowed is just below two milligrams of THC. A cannabis dose for pain begins at around two milligrams and for most new medical cannabis patients tops out at about ten milligrams per dose. In a study of smoked cannabis at University of California, San Diego, researchers noted a "sweet spot" of dose for smoked cannabis in treating pain. Too small a dose produced little relief, while too high a dose actually increased the pain levels in the study subjects. Cannabis dose for pain relief presents a "Goldilocks" conundrum to find a dose that is "just right." Most individuals unused to the effects of THC in cannabis become uncomfortably high at doses of fifteen milligrams or more.

Another challenge of taking cannabis orally is that only 10 to 20 percent of the dose reaches systemic circulation after its liver transformation into 11-hydroxy-THC. On an empty stomach, the onset of effects is typically thirty to sixty minutes and the THC psychoactivity lasts four to eight hours. Medicinal effects such as appetite stimulation can persist for 24 hours or more after a dose of THC.

Seven grams of twelve percent THC high-quality indoor cannabis infused into fifty grams of butter in slow cooker at 200 degrees for three hours will extract around 600 milligrams of THC. (For geeks, there is some loss in converting raw acidic THC to bioactive THC when heated by cooking, vaporizing or smoking. The raw THCA gives up a carboxyl group and converts to its neutral THC form. Additionally, the butter extraction method is not perfectly efficient.) That butter infused into a batch of twenty cookies will result in a cookie containing thirty milligrams of THC, which would be considered three portions under Colorado's cannabis edible regulations.

Here are some basic anecdotal rules of thumb concerning THC dose for occasional cannabis users. Again, these are anecdotal and should not be considered professional or medical advice. Remember that there are genetic differences among individuals, so doses and onset times vary.

2 mg: threshold of psychoactivity for infrequent users. Very little to no impairment.

2.5 mg: most report psychoactivity equal to a glass of wine or a beer. Doses in this range are popular for social anxiety, encouraging the munchies, and focus.

5 mg: nearly all occasional users will note significant psychoactivity. Significant appetite stimulation. Mild psychoactivity, akin to two to three glasses of wine.

10 mg: Strong psychoactivity for most occasional users. Significant distraction from pain. This dose is often recommended by physicians to stem nausea from chemotherapy.

15 mg: Most occasional users report uncomfortable levels of psychoactivity at this dose. Regular users of cannabis do not.

1000 mg: the most potent edible available in California dispensaries. This is ten times the maximum THC content of the edibles permitted by law to be sold in Colorado adult-use cannabis shops.

Why are there thousand-milligram cannabis edibles? That seems impossibly strong.

Because individuals that consume a lot of cannabis, and consume it often, develop receptor down-regulation, building up a tolerance to effects of cannabis. In a research study, participants were given over 200 milligrams/day of THC everyday. In just twelve days, those enormous doses were no longer getting the participants uncomfortably high, because the density of their cannabinoid receptors was reduced in response to this chronic exposure. The good news about cannabis tolerance is that it appears completely reversible. Twenty-eight days of abstinence from THC has been shown in another study to up-regulate cannabinoid receptors to their normal density.

What about cannabidiol, or CBD, in edibles? People are talking about that the therapeutic effect of CBD these days.

CBD when combined with THC can reduce some of the adverse effects of THC. However, patients report that when combined, CBD and THC, at low doses, appear slightly synergistic and produce more psychoactivity together. In a British study, hair samples from regular cannabis users that contained both THC and CBD were associated with far fewer self-reported episodes resembling psychosis than hair samples that contained only THC. It is thought that CBD may prevent some of the long-term adverse effects of THC use. Edibles and tinctures containing only CBD are popular with patients suffering from anxiety, some mental illnesses and seizure disorders. A CBD/THC prescription medicine called Sativex is available in Europe and Canada. It is currently undergoing the approval process in the US.

How can the average person determine dose when they're buying herb or cannabis edibles?

It's very difficult to do it without access to lab-tested cannabis, or engaging in careful trial and error experimentation. Far too few individuals have access to lab-tested and properly labeled herbal cannabis, extractions and infusions, which are only available in Washington, Colorado, California, Oregon, New Mexico, Arizona and Canada. Cannabis testing facilities will continue to open as more states reform their cannabis laws to enable medical and adult access.

How can users best ensure they have a pleasant experience when using a cannabis edible?

Know the dose. The most crucial advice is to know the dose of what's being consumed. Most unpleasant edible experiences begin with taking an edible of unknown potency, made by someone with a high tolerance to THC, then shared with a person with little tolerance for THC. Taking an edible of unknown potency is psychoactive Russian roulette. Always begin with a tiny fraction of any unlabeled edible, then wait a full three hours to gauge the intensity of its effects.

The setting in which the edible is being consumed is also important. A relaxed, unpressured environment is certainly more conducive to the more intense psychoactivity of a higher THC dose than when the same dose is consumed in a demanding environment surrounded by strangers. On the other hand, a very small dose of THC or especially CBD is reported by patients to reduce social anxiety.

What about kids and pets?

The palatability of cannabis edibles containing THC means they need to be kept away from any unsuspecting adult, child or animal. Always. No exceptions.

What should someone do if they realize they have taken too much cannabis?

Doctors I've asked say a Pixar movie, then a nap. A little caffeine seems to help reduce the effects, but never when someone is too anxious. It is easier to avoid the problem than fix it. And avoid alcohol and nicotine, both of which are mildly synergistic with THC. Children and pets may need medical attention, which is why cannabis edibles should always be kept far away from kids and companion animals.

What do you do, and what is your background?

I design and formulate edibles. I come from a design and engineering background and also have a strong interest in gastronomy and ethnobotanicals. The challenge of how to create more precise and palatable edible cannabis medicines was appealing and I've found working with people in need of cannabis medicines to be deeply satisfying. I've licensed my formulations to a few dispensaries in California and they make them to my specifications.

What makes your approach to edibles different?

I design edibles for patients seeking the minimum effective dose of cannabis for the condition for which their physician has recommended the use of medical cannabis. They want to minimize impairment. The Full Upright Position line of cannabis infused products that I designed are intended to provide no more impairment than a glass of wine. I wanted to design a product that a patient on a treatment course from their physician could use immediately, reducing the risk of a Maureen Dowd-style dose nightmare.

What about pain, and cancer patients who need higher doses to help with issues like post-chemotherapy nausea and vomiting?

I designed a product called Kaya that has been licensed by a few dispensaries in Los Angeles. Kaya is extremely potent and contains eight 10 milligram doses.

Do you have any products that contain CBD?

Currently the Kona line that I designed provides low doses of both CBD and THC. Later this year, I plan to license two additional formulations that contain CBD: Nova and Kaya CBD.

Where can the products that you formulated be found?

They are available in Los Angeles. Three dispensaries have licensed the formulas and produce them for their patients.

• Los Angeles Patients and Caregivers Group



• Koreatown Collective



• Pure Life Wellness



• California Patients Alliance



• Buds and Roses

Previously at Boing Boing

• How I use medical marijuana: vaporizers, science, weed, and cancer

• My Dinner with Marijuana: chemo, cannabis, and haute cuisine

Special thanks to Ascent by DaVinci for sponsoring this series. Ascent is a temperature-controlled, glass-on-glass vaporizer for people who care about quality.