A Little Dab Will Do You: Or Maybe Not?

Inhalable, noncombustible cannabis products are playing a leading role in the use of the medical and recreational cannabis products. Specifically, the practice of “dabbing” has exponentially grown in popularity in states where medical and recreational cannabis consumption has been legalized.

Dabbing involves inhaling vapors produced by placing a small amount of cannabis extract (a “dab”) on a small heated surface (the “nail”), which is connected to a water pipe ( 1 ). The most popular dabs are known as butane hash oil (BHO) dabs mainly because the concentrate is produced by passing the solvent butane over cannabis buds and leaves ( 2 ). Butane is subsequently removed from the extract under vacuum at room temperature or by heating in an oven. Differences in processing can lead to different dab consistencies that are colloquially known as shatter, budder, crumble, pull-and-snap, wax, etc (3, 4).

BHO have a tetrahydrocannabinol (THC) and cannabidiol (CBD) concentrations ranging between 50 and 90% (2). Consumers consider dabbing to be a form of vaporization, and, therefore, view it as easier on the lungs than smoking ( 5).

While delivery of harmfully-large amounts of cannabinoids (Pierre) may represent a potential danger to consumers, little is known about the toxicants that the process may produce. According to a recent paper entitled “Toxicant formation in dabbing: the terpene story (4) by a group of Portland State University researchers the high heat commonly used to heat dabs (concentrated cannabis extracts) exposes users to high levels of methacrolein (lung, throat and eye irritant), benzene (carcinogen) and other potential toxic degradation products which are known to pose human health risks (4).

The authors determined that the source of the potentially harmful degradation products may be the terpenes (compounds that give cannabis its odor and flavor) that are routinely concentrated in BHO dabs (4).  Myrcene is the most abundant terpene in cannabis, followed by limonene, linalool, pinene, caryophyllene, and humulene (4). Also, cannabis can contain trace amounts of up to 68 other terpenic compounds (6). Terpene content in BHO can range from 0.1 to 34% (4).

Another potential health risk is residual butane (a known carcinogen) that can be left behind if BHO dabs are not processed correctly (1, 2). Because of this, CO2 oil (another extraction method for dabbing) and alcohol extracts are the only allowable medical extracts to be sold under medical cannabis regulations in New York, Minnesota, Ohio and Pennsylvania (4). While commercially prepared BHO is on the rise in mature markets like California and Denver, much HBO is still made via “backyard-chemist” style operations so users beware.

Finally, while the results of this study are intriguing, I believe that much more research will be required to determine whether or not high heat terpene breakdown products pose actual health risks to dabbers.


  1. Stogner JM, Miller BL. The dabbing dilemma: A call for research on butane hash oil and other alternate forms of Cannabis. Subst. Abuse 2015; 36:393– 395
  2. Stogner JM, Miller BL. Assessing the dangers of “dabbing”: mere marijuana or harmful new trend? Pediatrics 2015: 136: 1– 3
  3. Pierre JM, Gandal M, Son M. Cannabis-induced psychosis associated with high potency “wax dabs” Schizophr. Res. 2016; 172:211– 212
  4. Meehan-Atrash J, Luo W, Strongin RM. Toxicant formation in dabbing: the terpene story ACS Omega, 2017; 2:6112–6117
  5. Gieringer D, St. Laurent J, Goodrich S. Cannabis vaporizer combines efficient delivery of THC with effective suppression of pyrolytic compounds J. Cannabis Ther. 2004; 4:7 – 27
  6. Ross SA, ElSohly MA. The volatile oil composition of fresh and air-dried buds of Cannabis sativa J. Nat. Prod. 1996: 59:49– 51

Cannabis Extraction: Myths and Truths

There was an interesting article recently published by Markus Roggen PhD an organic chemist and cannabis expert, who reviewed the “dos” and “don’ts” when conducting Cannabis extractions.  DIY cannabis extractions are currently very popular because of the recent dabbing craze. Nevertheless, perhaps the most important point of the article concerns the need for quality control in the cannabis extraction industry to ensure that consumers “get what they are paying for” and that the products they use are safe.

We are in the early days of industrial scale cannabis extractions and like other industries, e.g. food and beverage, pharmaceuticals and biotechnology etc,  where production must be regulated and quality control measures enforced, similar quality standards that guide extractions and production must be created for the cannabis industry.  While this may not be viewed favorably by some current leaders of the cannabis industry, it will be necessary to establish the credibility of the industry and ensure the quality and safety of cannabis and its products as the industry continues to evolve and mature.

The Dangers of Dabbing

Dabbing or “doing a dab” is a new method of Cannabis consumption that is growing in popularity.   The reason why dabbing Cannabis concentrates is preferable to smoking Cannabis flower is a reduction in the number of inhalation to achieve desired effects, increased potency and longer lasting effects (Raber et al).  While dabbing is gaining in popularity (mainly among recreational users (1), there may be some hidden safety issues  and health concerns with the practice.

Concentrated Cannabis products are prepared by a variety of different methods (Fig 1).

Fig. 1.  Different types of Cannabis concentrate preparation (from Raber et al.[1])

While dry and water-based extraction methods have been traditionally used to make concentrates like fief, hash and others, solvent-based extractions are increasingly being used to make Cannabis concentrates. Most solvent-based concentrates are made by extraction of plant material with organic solvents such as isopropanol, acetone  hexane and others.  Unfortunately, these solvents are toxic and carcinogenic (can cause cancer). Often, residual solvent residues are found in concentrates and ought to be a health concern for Cannabis users.

Likewise, liquid gas-based extractions that use low boiling hydrocarbon gases such as butane and propane to make Cannabis concentrates  are popular.  Because pressure or cooling of these solvents is required, there is a very good possibility of catastrophic explosions and fires if these extractions are performed by unskilled persons (2).  Also, another concern with liquid gas extractions is the quality of the solvent that is used.  Frequently, these solvents are industrial grade,  not pure and may contain lubricating oils which can end up in the concentrate.  Finally, like chemical extraction methods, high levels of residual solvent used in the liquid gas extraction may be present the final product which can be harmful to the end user.

Because of the possible safety and health consequences, chemical Cannabis extraction is illegal in California (3).  Instead, many extracts are produced by using compressed CO2 as the extraction solvent–thereby avoiding the use of flammable and toxic chemical solvents.

Recently, Raber et al. (1)  analyzed 57 Cannabis concentrates available in the California Cannabis marketplace.  Over 80% of these concentrates was contaminated either by residual solvents or pesticides.

The take home message? While dabbing offers a longer-lasting more intense Cannabis experience, dabbers may be exposing themselves to short-term safety issue and possible long-term health consequences.


  1. Raber JC, Elzinga S, Kaplan C. Understanding dabs;contamination concerns of cannabis concentrates and cannabinoid transfer during the act of dabbing. J. Toxicol. Sci. 2015; 40:797-803
  2. Jensen G, Bertelotti, R, Greenhalgh,  Palmieri T,  Maguina P.  Honey oil burns; a growing problem.  J. Burn Care Res.  2015; 36:34-37
  3. Monzingo, J. Making butane hash a lethal mix in home drug labs. 2014 http://articles.latimes.com/2014/feb/05/local/la-me-butane-hash-20140206 accessed June 29, 2017

What is Dabbing and Why Is It So Popular?

Dabbing is a relatively  new method of delivery that involved placing a small amount of Cannabis extracts or oils—a dab—onto a heated surface (usually titanium or quartz and known as a “nail”) and vaporizing it on contact. Like vaporization, cannabinoids pass directly from the lungs to the bloodstream and produce immediate effects.  It is important to note, that dabbing can accommodate only Cannabis extracts or oils not actual Cannabis flower or plant material.

Dabbing requires a delivery device  colloquially  known as a “dab or oil rig” (Fig. 1)

Fig 1.  A dab rig.  Source: You Tube Video

In a recent paper entitled “Tracking Dabbing Using Search Query Surveillance: A Case Study in the US” Zhang et al. (1) found, that based on the volume of Google searches from  2004-2015, dabbing is rapidly growing in popularity among US Cannabis users (Fig. 2).

Fig. 2.  National trends for dabbing-related Google searches in the US, 2004-2015. (from Zhang et al)

The researchers also found a coincidental increase in the number of searches associated with e-cigarettes or electronic nicotine delivery systems (ENDS; Fig. 2)

The average dabbing searches were significantly higher in states in which medical and recreational Cannabis were legalized as compared with states with only medical Cannabis legalization ( P=.02)  [Fig. 3].

Fig. 3.   Map of raw searches for dabbing in the US, 2004-2015. (from Zhang et al)

While it is not clear why dabbing has become increasingly popular, it is likely that this delivery methods offers Cannabis users with doses that are higher in delta-9-tetrahydrocannabinol (THC) and other cannabinoids.  Interestingly, the authors suggest that dabbing surpassed Cannabis edibles and smoking in the middle of 2013 as the preferred alternative form of Cannabis consumption.

Despite its growing popularity, dabbing is not without risk.  This will be the subject of another post!


  1. Zhang Z, Zheng X, Zeng, DD, Leischow S. Tracking dabbing using search query surveillance: a case study in the United States.  J. Med Internet Res. 2016; 18:e252.

Optimizing Cannabis Delivery

The plethora of therapeutic benefits offered by Cannabis has largely been attributed to a class of naturally-occurring, plant-derived chemicals terpenophenolic compounds known as phytocannabinoids (1, 2). Over 60 pharmacologically-active cannabinoids have been identified to date (3).

While inhalation (smoking and vaporization) and ingestion are the most common routes of administration of Cannabis products but other routes including rectal, sublingual, transdermal, ophthalmic, intrathecal and intravenous routes have been used (4).


Historically, smoking is the most common and easiest method for Cannabis delivery. Scientifically-speaking, smoking is inhalation of smoke produced by combustion of the Cannabis flower or concentrated forms of Cannabis. Smoking allows users to immediately feel Cannabis’ effects because inhaled smoke containing cannabinoids like THC, CBD and others (2) passes directly from the lungs into the bloodstream.  These blood-borne molecules instantaneously bind to Cannabinoid receptors, CB1 and CB2 (6, 7) and mediate the various psychoactive and therapeutic effects of Cannabis.


Vaporization involves heating Cannabis or concentrates//extracts to temperatures slightly lower than combustion. This technique causes cannabinoids and other molecules found in Cannabis to reach their individual boiling points (which are lower than their combustion points) and vaporize in the absence of combustion (8). By avoiding combustion, the toxic byproducts generated by smoking Cannabis are greatly reduced and the effective dose of Cannabinoids are enhanced (combustion destroys a larger percentage of cannabinoids as compared with vaporization). Like smoking, vaporized Cannabis passes directly from the lungs into the bloodstream and its effects are felt almost immediately.


Dabbing is a new method of delivery that involved placing a small amount of Cannabis extracts or oils—a dab—onto a heated surface (usually titanium or quartz and known as a “nail”) and vaporizing it on contact.

Like vaporization, cannabinoids pass directly from the lungs to the bloodstream and produces immediate effects. It is important to note, that dabbing can accommodate only Cannabis extracts or oils not actual Cannabis flower or plant material.

While becoming increasingly popular, dabbing can be dangerous if the right Cannabis extraction methods and appropriate equipment are not used.

Oral Delivery

Oral delivery of Cannabis and its products usually involves eating. Unlike smoking, it can take up to 2 hours or more to experience the effects of ingested Cannabis because cannabinoids are slowly absorbed into the bloodstream during digestion. Also, when ingested, Cannabis is metabolized by the liver cytochrome system and Δ-9-THC (Delta 9 Tetrahydrocannabinol) is converted to 11-hydroxy-THC, a more potent form of THC (9).

Oral delivery of Cannabis can include edibles (brownies, cookies, cakes, candy or fruit snacks), Cannabis oil/extract capsules and Cannabis-infused beverages.

Other oral delivery routes include sublingual delivery (under the tongue) or oromucosal sprays. Cannabis tinctures are frequently used for sublingual delivery and extracts are frequently delivered via the oromucosal route. Unlike ingestion, Cannabis products delivered via the sublingual or oromucosal routes are quickly delivered to the bloodstream and offer immediate effects.

Topical/Transdermal Delivery

Whereas other methods of Cannabis delivery offer systemic (body wide) effects, topical application of Cannabis salves, balms and creams generally offer more localized action (although high enough doses and repeated use of these products can sometime lead to systemic effects). These products are useful to treat arthritis, chapped skin, eczema, minor burns, muscle soreness, sunburns, swellings, joint pain, and tendonitis

Topical delivery is becoming more widespread for persons who use Cannabis for medical rather than recreational purposes. Currently, Cannabis developers are experimenting with controlled-dosage transdermal patches to treat persons with chronic illnesses (10, 11).

Cannabis Suppositories

Other Cannabis delivery method involves rectal suppositories.  Like smoking, vaporization and sublingual/oromucosal delivery, rectally-delivered Cannabis extracts/oils are rapidly absorbed into the bloodstream via the colon and provide long lasting effects. Albeit not the most appealing or dignified delivery methods, Cannabis suppositories are effective.


  1. Alexander A, Smith PF, Rosengren RJ. (2009) Cannabinoids in the treatment of cancer. Cancer Letters 285(1):6-12.
  2. Aizpurua-Olaizola O, Omar J, Navarro P, Olivares M, Etxebarria N, Usobiaga A. (2014) Identification and quantification of cannabinoids in Cannabis sativa L. plants by high performance liquid chromatography-mass spectrometry. Analytical and Bioanalytical Chemistry 406(29):7549-7560.
  3. Gerra G, Zaimovic A, Gerra ML, et al. (2010) Pharmacology and toxicology of Cannabis derivatives and endocannabinoid agonists. Recent patents on CNS drug discovery 5(1):46-52.
  4. .Bowles DW, O’Bryant CL, Camidge DR, Jimeno A. (2012) The intersection between cannabis and cancer in the United States. Critical Reviews in Oncology/Hematology 83(1):1-10.
  5. Aizpurua-Olaizola O, Omar J, Navarro P, Olivares M, Etxebarria N, Usobiaga A. (2014) Identification and quantification of cannabinoids in Cannabis sativa L. plants by high performance liquid chromatography-mass spectrometry. Analytical and Bioanalytical Chemistry 406(29):7549-7560.
  6. Elphick MR, Egertova M. (2001) The neurobiology and evolution of cannabinoid signaling. Philosophical transactions of the Royal Society of London. Series B, Biological Sciences 356(1407):381-408.
  7. Grotenhermen F. (2005) Cannabinoids. Current Drug Targets CNS And Neurological Disorders 4(5):507-530.
  8. Hartman RL, Brown TL, Milavetz G, Spurgin A, Gorelick DA, Gaffney G, Huestis MA. (2015 ) Controlled Cannabis Vaporizer Administration: Blood and Plasma Cannabinoids with and without Alcohol Clin Chem.;61(6):850-69
  9. Newmeyer MN, Swortwood MJ, Barnes AJ, Abulseoud OA, Scheidweiler KB, Huestis MA Free and Glucuronide Whole Blood Cannabinoids’ Pharmacokinetics after Controlled Smoked, Vaporized, and Oral Cannabis Administration in Frequent and Occasional Cannabis Users: Identification of Recent Cannabis Intake (2016) Clin Chem. 62(12):1579-1592
  10. https://www.cannabisscience.com/index.php/news-media/cbis-latest-news/805-cannabis-science-announces-pharmaceutical-development-of-pain-patch-for-patients-with-diabetic-nerve-pain-and-fibromyalgia Accessed June 27, 2017
  11. https://cannabis.net/blog/medical/transdermal-cannabis-patches-the-future-is-here  Accessed June 27, 2017