how much cbd oil should i take for allergies

An emerging allergen: Cannabis sativa allergy in a climate of recent legalization

Considering its recent legalization in Canada, the health implications of Cannabis sativa exposure, including allergy, are coming to the forefront of medical study and interest. C. sativa allergy is an issue that affects recreational users of the substance, processors, agricultural workers, and contacts of Cannabis aeroallergens and secondhand product. Allergies to C. sativa are heterogenous and span the spectrum of hypersensitivity, from dermatitis to rhinoconjunctivitis to life-threatening anaphylaxis. Due to its recent legalization, sensitized individuals will have increasing exposure from direct contact to agricultural pollens. Diagnosis and treatment of Cannabis allergy are developing fields that are already showing promise in the identification of culprit antigens and the potential for immunotherapy; however, much responsibility still falls on clinical diagnosis and symptom management. Hopefully, given the current explosion of interest in and use of Cannabis, C. sativa allergy will continue to garner awareness and therapeutic strategies.


Cannabis sativa allergy is a hypersensitivity that has recently been gaining relevance and is of particular interest due to recent legalization in Canada. Approximately 17% of Canadians, and 27% of those 25–24 years old, report Cannabis use within the past 3 months [1]. Cannabis sativa allergy is expected to increase as a consequence of legalization due to increased exposure. Additionally, as legal and stigma-related barriers to use subside, an unintentional side effect of legalization may be increased reporting of current suspected cases of Cannabis allergy. Given the potential for increases in existing and reported allergic reactions to Cannabis, building an understanding of C. sativa allergy spectrum, diagnosis, and treatment will be important moving forward.

The purpose of this article is to provide an overview of the current understanding of Cannabis allergy and place it within a Canadian context. This article also highlights that exposure extends beyond recreational use and includes second-hand exposure, ingestion, aeroallergen contact, and cutaneous contact.

Spectrum of C. sativa allergy

Cannabis is a complex genus of dioecious, annual, wind-pollinated herbs that diverged from Humulus—a small genus that includes H. lupulus, whose bitter female flowers form the hops used to flavor beer—approximately 27.8 million years ago [2]. Cannabis is among humanity’s oldest crops with records of its use for food, fiber, medicine, and inebriation dating back over 6000 years. Despite its long history of use, its taxonomy remains disputed, with some suggesting a monotypic classification with several subspecies of C. sativa [2], and others suggesting three distinct species (C. sativa, C. indica, and C. ruderalis) [3, 4]. The biochemistry of Cannabis is similarly complex, with at least 118 cannabinoids and 489 described constituents, the most well know and psychoactive of which being tetrahydrocannabinol (THC) and cannabidiol (CBD) [5]. “Indica” varieties of Cannabis tend to have a higher THC content, and higher THC to CBD ratio than “sativa” varieties [2]. “Indica” varieties are known for a more mellow high and a terpenoid profile with an acrid, skunk smell, whereas “sativa” varieties are known for a more exciting high and a sweet, herbal aroma [2]. However, these strains are heterogeneous with genome-wide variability that is not limited solely to the genes involved in THC and CBD production [4].

Study of specific culprit Cannabis allergens is still in its infancy. A handful of IgE immunoblot experiments, summarized in Table 1, have identified several potential allergens. Of these, the Cannabis non-specific lipid transfer protein (nsLTP), Can s 3, was the first identified and is the best studied [6]. Thaumatin-like protein (TLP), ribulose-1,5-bisphosphate carboxylase oxygenase (RuBisCO), and oxygen evolving enhancer protein 2 have also been recognized as potential sensitizing allergens in Cannabis allergy [7, 8].

Cannabis sensitivity spans the spectrum of allergic response. As an aeroallergen, Cannabis pollen has been implicated in allergic rhinitis, allergic keratoconjunctivitis, hypersensitivity pneumonitis, and exacerbations of asthma symptoms [9] (Fig. 1a). Additionally, patients may experience cutaneous reactions in the form of generalized pruritus, contact urticaria, and angioedema. A case of occupational contact urticaria was reported in a forensic sciences technician who had regular occupational contact with Cannabis for a period of 2 years. She was neither a recreational user, nor an atopic or dermatographic individual, suggesting sensitization specifically from repeated handling [10]. Erythema multiforme (in one case report) has also been associated with recreational consumption [11]. This individual experienced the eruption of vesicobullous, scaled, and targetoid rash on his distal extremities which progressed proximally to his trunk within a two-week period, waxing and waning synchronously with his use of Cannabis [11]. Anaphylaxis to C. sativa with hempseed ingestion, smoking, and injection have also been reported [12,13,14].

a Indicates the different types of allergic reactions and associated exposures to Cannabis sativa (C. sativa). b Shows cross-sensitizations between C. sativa and fruits, vegetables, tobacco, alcohol, and latex

Cannabis has reasonably common, expected, but undesirable physiologic effects (conjunctival injection, sinus tachycardia, orthostatic hypotension, anxiety or panic reactions, dysphoria). It is important to not ignore or mis-attribute similar symptoms when the index of suspicion for a serious reaction or anaphylaxis is high [9].

Cannabis consumption also carries a risk to immunosuppressed patients in the form of microbiological contaminants, particularly when inhaled. Aspergillus has been isolated repeatedly from Cannabis samples [15, 16]. In one observational study, a majority of Cannabis users had antibody evidence of Aspergillus exposure compared to a minority of abstinent controls [17]. Furthermore, cases of pulmonary aspergillosis have been linked to contaminated Cannabis use in immunosuppressed populations [16, 17]. Fungal spores resist destruction from smoking and vaporization [18]. Thus, hypersensitivity and immunosuppression are clinically relevant states with regard to Cannabis consumption.

Sensitization to C. Sativa

Sensitization to Cannabis can occur via inhalation, cutaneous exposure, ingestion, and secondhand exposure, and can occur in recreational users and occupational handlers. Specifically, sensitization and reactions have been seen with smoking, consuming, injecting, and handling Cannabis plants, the latter being most germane to industrial workers [19,20,21]. As the Cannabis agricultural industry grows, C. sativa may also become a significant aeroallergen. Indeed, Canada’s first large-scale commercial outdoor Cannabis farm began operations in mid-summer 2019 [22]. The potential role of Cannabis pollen as an aeroallergen has long been realized in agricultural regions. For example, in Nebraska, peak season pollen counts show Cannabis comprising 36% of the total airborne burden, and additionally correlating with a skin-test positive allergic symptom surge during mid to late August [23].

In light of this increase in Cannabis aeroallergen, we may also begin to see an increase in Cannabis-fruit/vegetable syndrome. As with other forms of food-pollen or oral allergy syndrome, Cannabis-fruit/vegetable syndrome is thought to occur due to structural homology and antigenic similarities between nsLTPs in C. sativa and those in cherry, tangerine, peach, tomato, hazelnut, latex, and tobacco (Fig. 1b), resulting in cross-sensitivity and reaction to consumption of these products [7, 9, 19]. However, unlike birch pollen-related food-pollen syndrome, Cannabis-fruit/vegetable syndrome may cause more severe symptoms (including anaphylaxis to previously tolerated fruit). Sensitization is bidirectional; i.e. sensitization to an nsLTP in fruits can cause subsequent sensitization to Cannabis [7, 19, 20]. Thus, a variety of exposure routes exist for C. sativa sensitization, and these sensitizations may be primary or cross-reactive.

Diagnosis of C. sativa allergy: an evolving practice

Clinical history is the cornerstone of diagnosing Cannabis hypersensitivity. As with any other allergic presentation, a complete history will include a detailed review of the presenting suspected reaction (Table 2). The history should also include a thorough review of atopic history, medical history, medications, social history including recreational and occupational exposures, and family history including atopy and asthma. With respect to diagnostic testing, the “gold standard” allergen challenge may not be appropriate in Cannabis allergy. Although Canadian law would permit access to and use of the substance unlike many regions, there is dispute regarding expected reaction phenotypes, particularly regarding varied and paradoxical lower airway response [20]. Thus, Cannabis graded challenge is not yet a viable, routine diagnostic option. Epicutaneous testing is currently not standardized for C. sativa. Skin testing described in current literature is heterogenous and requires the suspension of marijuana buds, leaves, and/or flowers to be produced and administered by the allergist [20]. In vitro assays of serum specific IgE (sIgE), cytometric basophil activation (BAT), and basophil histamine release using crude extracts, purified components and recombinantly expressed allergens have shown promising results, but remain commercially unavailable [20, 21, 24, 25].

The isolation of specific Cannabis antigens will facilitate standardized skin prick and serum IgE testing. Recently, Decuyper et al compared specific IgE (sIgE) testing to hemp, sIgE to a recombinant Can s 3 (rCan s 3) protein, BAT to the same rCan s 3, and skin prick testing with a Can s 3 antigen-rich extract in diagnosing Cannabis allergy [20]. The Can s 3 extract, which is not commercially available, was prepared for study using methods previously described for isolating nsLTPs from tomato, with total protein quantification using Micro BCA Protein Assay [20, 24, 26]. The results of the comparison suggested that Can s 3 is the superior antigen for testing, and that skin prick and sIgE testing are effective and practical, with respective sensitivities of 72% and 81% and specificities of 63% and 87% [20]. While promising, the authors address the clear issue of lack of commercial availability of these extracts. They suggest that, with current clinical limitations, a sIgE to hemp (which is currently available from Thermo Fisher) may be appropriate for diagnosis as only 18% of Cannabis sensitized individuals have negative IgE to hemp. However, it would still be ideal that a commercially available Can s 3 extract become available.

Treatment of C. sativa allergy

The only proven, currently available treatment for Cannabis allergy is avoidance. However, when avoidance is impossible, treatment of C. sativa allergy is identical to that of other allergens: based on the index reaction to the substance. Treatment with antihistamines, intranasal corticosteroid sprays, and ophthalmic antihistamine drops can provide symptom relief [9]. All individuals with anaphylactic allergies should carry auto-injectable epinephrine. Treatment for Cannabis-fruit-vegetable syndrome is also dependent on avoidance.

Promising but limited case reports suggest future directions for the treatment of Cannabis allergy. For example, Engler et al. described an occupationally exposed individual with anaphylaxis to Cannabis who was successfully treated for with Omalizumab therapy [27]. Kumar et al. successfully implemented a perennial subcutaneous immunotherapy schedule that reduced a patient’s symptoms of allergic rhinitis and asthma during Cannabis pollen season [28]. This was delivered as subcutaneous, twice-weekly doses starting with 1:5000 weight/volume of diluted antigen, beginning at 0.1 mL and increasing by 0.1 mL per injection to a target maintenance dose of 1 mL of 1: 50 antigen concentration per month for 1 year [28].

Hopefully, in light of the rise of C. sativa use and agriculture, desensitization protocols will become available for sensitive patients as demand increases. Nonetheless, avoidance and traditional methods of managing allergic reactions continue to be the basis of treatment for Cannabis allergy.


The legalization and accessibility of Cannabis sativa in Canada has created a renewed interest in the health implications of its use, including allergic and immunologic consequences. This brief review has highlighted the diversity of sensitization routes and reactions to the plant, emphasizing the heterogenous presentation of Cannabis allergy. In addition, this article has underscored the fledgling nature of available testing and treatment options for C. sativa allergy. There have been recent, exciting advancements in isolation of culprit allergens and clinical testing, although these are not yet applicable to general office use. At the moment, there are existing practical suggestions for diagnosing and treating C. sativa allergy, which will hopefully evolve in the coming years as Can s 3 preparations and immunotherapy schedules mature and become commercially available. However, currently, a detailed allergy history with adjunct hemp sIgE testing are the cornerstones of diagnosis, and avoidance (in combination with standard symptomatic treatment) is the mainstay of treatment.

How much cbd oil should i take for allergies

A breakdown of common terpenes found in cannabis and their therapeutic effects

The Takeaway

Many people who suffer from seasonal allergies and hay fever are looking to cannabis and CBD as a more natural approach to easing their symptoms. Anecdotally and clinically, the evidence seems convincing that it may indeed play a positive role for those who suffer from troublesome symptoms. While cannabis cannot offer a magic wand for relief, there may be products available that can provide a pathway to a more bearable allergy season. Our state-certified medical cannabis consultants are the best resource for identifying what products may be most helpful.

How much cbd oil should i take for allergies

CBD Oil 101:

  • CBD — stands for Cannabidiol, it comes from the Cannabis (hemp) plant.
  • Where does it work in our bodies? Our bodies have something called the Endocannabinoid System (ECS), just like we have a nervous system and circulatory system. The ESC is full of neurotransmitters and receptors designed to utilize CBD, and is integral for the regulation of many body functions. These include but are not limited to; appetite and nausea, pain reception, neuroprotection, muscle movements, stress, memory, sleep, and homeostasis.
  • Is it legal? YES! You do not need a special card or prescription.
  • Will it get me high?* Nope. Federal regulations require industrial hemp to contain less than .3 percent THC, which is what produces psychotropic effects.
  • Will my body recognize and know how to use CBDs? Yes, we all have built-in receptors, like the CB1 and CB2 receptors that are always ready for Cannabinoids to do work: it is a square peg, square hole scenario.
  • I have a lot of pain/ anxiety, so I should take the higher potency, right? Not quite: those receptors mentioned above are only ready for a little CBD at the beginning, and gradually increase their ability to incorporate CBD into our system. Why not take high amounts? See below.
  • *What happens if I take too much CBD? Overwhelming your receptors can lead to something called reuptake inhibition which can lead to a spacy feeling, and in some cases of people prone to anxiety, this can increase anxiousness.
  • Contraindications: are you on any medications where you aren’t supposed to drink grapefruit juice? Then it is possible that higher doses of CBD could interact with your medication as well. Some medications are passed out of your body by a liver enzyme called CYP450 (also CYP2D6), and CBD oil, like grapefruit juice and several other herbs and foods, takes up some of that same enzyme so that the medications may not as effectively be passed out. You should ask your healthcare provider about any medications you are currently taking, and how they would be affected by CBD.
  • Allergies: Please note that Cannabis is in the same family as Nettle. If you are allergic to nettle, hops, or any herb in that family, please consider the possibility that CBD would be unsuitable for you. Persons with Tree Nut Allergies should know that many CBD formulas contain MCT/coconut oil. Please read ingredients carefully.

Other Things That Are Great for the Endocannabinoid System

While CBD is helpful for many individuals, there are base-line nutrients that can improve results of CBD as well as maintain overall good health.

Omegas: increasing your omega intake can improve the effect of your purchased CBD product, as well as improve your body’s own production of endocannabinoids. Your body uses its stores of fatty acids to rapidly create lipid-soluble compounds like CBD, so the more omegas you have stored in your cells, the better your body can respond to stimuli, like stress and exercise.

Magnesium: This vital nutrient is something that your entire body relies on for nutrient assimilation, cardiovascular health, cellular energy, stress reduction, the production of essential hormones like serotonin, and gene expression. Statistics reveal that close to 80% of Americans do not get enough magnesium daily.

  • “CBD Oil by Plus CBD Oil™ The Market Leader for CBD Sales.” PlusCBD Oil, CV Sciences,
  • “Endocannabinoid System.” Wikipedia, Wikimedia Foundation, 10 Feb. 2018,
  • “Myths and Truths About Minerals.” Heather Dane , 13 Oct. 2018,
  • Donvito, Giulia, et al. “The Endogenous Cannabinoid System: A Budding Source of Targets for Treating Inflammatory and Neuropathic Pain.” Neuropsychopharmacology, vol. 43, no. 1, 2017, pp. 52–79., doi:10.1038/npp.2017.204.
  • Hicks, John. Medicinal Power of Cannabis: Using a Natural Herb to Heal Arthritis, Nausea, Pain, and Other Ailments. Skyhorse Publishing, 2015.
  • “Omega3 Innovations.” Omega3 Innovations ,
  • Project CBD: Medical Marijuana & Cannabinoid Science. (n.d.). Retrieved from

** Please Note: When CBD oil is consumed on a regular basis, some NYS drug tests may test positive for THC. Though is it uncommon, it is important to understand that there can be a crossover of the recognition on tests.

This information is not intended to diagnose, treat, cure, or prevent any illness or medical condition. Everyone should consult with a health care professional before starting a new supplement, and embark on their own research path to practice appropriate self-health-care.