There is not enough clinical research to show that hemp is safe either orally or topically for women who are pregnant or breastfeeding, so it is not recommended.
Hemp seeds can be:
Hemp seeds’ nutty flavor and versatility also make them a great substitute for the levels of protein, essential fatty acids, and other nutritional benefits found in meat and dairy products.
The fiber content in hemp seeds can cause digestive discomfort like bloating, nausea, or constipation in large amounts. Make sure to drink plenty of water when eating hemp seeds to help avoid gut problems.
Hemp seed shells can contain trace amounts of THC, the active psychoactive compound in marijuana. People with a previous dependence on cannabis may consider looking for an alternative.
Hemp seeds are a great source of magnesium, which helps regulate your heartbeat and is linked to the prevention of coronary heart disease. They also contain Linoleic acid, which one study found reduced participants’ cholesterol levels by 15% and may act to reduce blood pressure.
Nutrients: “Dietary Magnesium and Cardiovascular Disease: A Review with Emphasis in Epidemiological Studies.”
If you are importing whole hemp seeds (seeds with their outer coat on) you need an import or export licence under the Misuse of Drugs Regulations from Medicines Control.
You do not need a licence from Medicines Control if you are importing or exporting hulled, non-viable hemp seeds and hemp seed food products.
Importing or exporting hemp seeds and hemp seed food products
You need a general licence issued by Medicines Control under the Misuse of Drugs (Industrial Hemp) Regulations 2006, with cultivation listed as an activity:
To sell hulled hemp seeds and hemp seed food products:
Growing hemp to use the seeds as food products
Hulled hemp seeds are seeds with the outer coat or hull removed that are not able to germinate. A licence from Medicines Control is not required if your activities start with hulled non-viable hemp seeds.
The better knowledge of the biochemical and biomolecular features of the C. sativa L. species has made it possible to understand the genetics and biochemical mechanisms previously described, which are the basis of the cannabinoids’ synthesis and, in particular, of THC. Furthermore, thanks to the development of specific analysis techniques (e.g., gas chromatography or gas chromatography-mass spectrometry), it is now possible to resolutely and accurately quantify the THC content of C. sativa L. plants in order to distinguish between cvs with high and low THC contents. For these reasons, nowadays, the cultivation of industrial hemp has been reintroduced either in the US, Canada, and Europe. Canada was one of the first country to restore industrial hemp cultivation. Indeed, in 1994, it began to issue licenses for hemp as a research crop and then, in 1998, the cultivation of hemp varieties containing less than 0.3% THC of the dry weight of leaves and flowering parts was legalized, and it is currently permitted, provided that a license from the Office of Controlled Substances of Health Canada has been acquired. To date, Canada is the major hemp-producing and -exporting country, particularly of hemp-based foods, ingredients, and other related products . In the EU, the hemp cultivation reintroduction took place in 2013 with the EU regulation n. 1307/2013 that allowed the growth of C. sativa L. plants for industrial purposes only for those plants with low levels of THC. According to this regulation, the granting of payments under the Common Agricultural Policy (CAP) is conditional upon the use of certified seeds of specific hemp varieties, that is, C. sativa L. cvs with a THC content not exceeding 0.2% of the dry weight of leaves and flowering parts . Thus, the EU has adopted more stringent parameters compared to Canada, to ensure the safety of and to protect the health of citizens. Different genotypes of industrial hemp with a THC content < 0.2% have been selected and registered, and currently, there are about 70 allowed industrial hemp varieties listed in the European Plant Variety Database as agricultural species ( Table 1 ) [37,38]. Some of these cvs are dioecious as the C. sativa L. plant naturally occurs; other cvs are monoecious and are obtained by ancestral breeding . Often, but not always, the monoecious varieties are adopted for seed production since they give a higher yield of the product of interest, whereas the dioecious cvs are mainly adopted for fibre production. Moreover, the industrial hemp varieties listed in the EU plant variety database are constantly updated based on the results of the annual THC-content’s monitoring and on the possible request for the introduction of new cvs with a low THC amount.
2.3. Legislation of C. sativa L.
Finally, another three literature works about the hempseed oil dietary supplementation in humans have been performed on patients affected by MS [147,148,149]. As described in the previous subsection (Section 4.1), the same authors have used an MS mouse model in order to understand the molecular mechanisms underlying the beneficial effects of the co-supplementation of hempseed oil and evening primrose oil on this neurodegenerative, immune-mediated pathology [141,142]. In previous works performed on humans, these authors observed that the co-supplementation of hempseed oil and evening primrose oil in a 9:1 ratio, used alone, or in association to a Hot-natured diet, was able to ameliorate the inflammatory status of MS patients, thus exerting a beneficial effect on this pathological condition. In particular, the authors explained that MS is a Th1-mediated autoimmune disease, which therefore, is characterized by an unbalance Th1/Th2 immune responses and high levels of pro-inflammatory IL-6, IFN-γ and IL-17 cytokines. This latter cytokine is produced by the Th17 cells which, hence, are involved in the development of the pathology, together with Th1 cells [147,148]. A Hot-natured diet is characterized by the consumption of foods with low cholesterol, hydrogenated, trans, and saturated FAs; a plenty of fruits and vegetables, nuts and seeds without additives, olive and grapes oils as the main oils of the diet, fish and seafood, and unrefined carbohydrates and dairy products with honey; contrarily, it excludes the consumption of sugar and refined carbohydrates, alcohol, and smoke. It has been shown that the consumption of the Hot-natured diet is related to a deviation of the immune system toward the Th2 responses. In addition, both hempseed oil and evening primrose oil possess anti-inflammatory features, related to the high PUFAs content and the perfectly balanced n-6/n-3 PUFAs ratio of the former and to the about 9% of GLA content of the latter. Based on all this evidence, Rezapour-Firouzi and co-workers in their studies [147,148] decided to adopt the hot-natured diet co-supplemented with 18–21 g of hempseed oil and evening primrose oil in a 9:1 ratio, as a potential useful dietary intervention for the treatment and attenuation of MS. The authors found that both types of dietary intervention (i.e., the Hot-natured co-supplemented with hempseed oil and evening primrose oil, and the co-supplementation of hempseed oil and evening primrose oil alone) for 6 months have exerted an effective anti-inflammatory action, leading to a significant increase in the IL-4 cytokine level on MS patients and to an improvements of the degree of the Th2/Th1 ratio, the expanded disability status scale (EDSS), and the relapse rate, which are all indexes of the disease severity, and thus performed a beneficial action in the patients, without exhibiting any side effects [147,148,149]. However, only the Hot-diet associated with the hempseed and evening primrose oils co-supplementation resulted in having also the ability to significantly decreased the level of the pro-inflammatory IFN-γ and IL-17 cytokines. Indeed, contrarily, the hempseed oil and evening primrose oil co-supplementation alone showed a decreased trend in the level of these cytokines, which though, was not statistically significant, at least after 6 months of the treatment . In a later report, the same authors  also demonstrated that both Hot-natured diet co-supplemented with hempseed and evening primrose oils and the co-supplementation of hempseed and evening primrose oils alone were able to improve the liver function in the MS patients, which generally showed a serious liver injury also as a consequence of the drug treatment, but the former dietary intervention was more efficient than the latter.
The high intrinsic genetic variability rate of C. sativa L. has been further accentuated by the long history of its domestication. Indeed, the different intended uses of the C. sativa L. cultivation’s products have led over the years, to an artificial phenotypic selection of specific features of the domesticated plants, useful for increasing the yield and/or the quality of the commercial interest’s cultivation products . The direct consequence of this selection was the unaware artificial creation of the C. sativa L. varieties, each with specific genotypic and phenotypic features, which at first, induced the taxonomists and botanists to erroneously recognize two or three different species of C. sativa L., embracing a polytypic concept of the Cannabis genus . To further complicate the taxonomic classification of the Cannabis genus, there has been also the fact that C. sativa L. is a crop which tends to exist in “crop-weed complexes”, that is complexes of domesticated forms in cultivation and related ruderal (weedy) forms growing outside of cultivation, developing morphological characteristics also very different from those of the domestic progenitor, as a consequence of adaptation to the wild environment . However, it must be considered that, despite the high genetic variability of C. sativa L., the varieties that genotypically and phenotypically differ, are interfertile. Therefore, taking into account the Darwinian definition of biological species, “a group of organisms that can reproduce with one another in nature and produce fertile offspring”, C. sativa L. varieties cannot be consider as different species of the Cannabis genus. For this reason, to date, the polytypic concept has been definitely given up and replaced by the monotypic one. According to this, a single species of Cannabis genus exists, namely C. sativa L., which includes several varieties or cultivars (cvs) that genotypically and phenotypically differ, but they all are interfertile and therefore, they belong to the same species [29,30].