Hemp, Marijuana, and Cannabis are terms often used interchangeably even though, there are separate definitions for all in place.
Further confusion is brought about when considering the chemicals: CBD and THC.
Cannabis refers to a group of plants containing 3 scientifically recognized species – Cannabis sativa, Cannabis indica, and Cannabis ruderalis. 
Within each species, there are different varieties of the plant. This is due to environmental changes (water, soil, land) between each location where the plants are grown and differences in the method of cultivation.
The differentiating factor between hemp and marijuana is very simple; it is just the total content of THC. 
Varieties of Cannabis sativa, Cannabis indica and Cannabis ruderalis with a total THC content of less than 0.3% are regarded as hemp.
Those with a THC content greater than 0.3% are defined as marijuana.
You might be wondering what THC is and why it is so important. THC is the psychoactive chemical constituent of Cannabis responsible for inducing the feeling of a ‘high’ upon smoking or ingesting marijuana.
The medicinal gains of Cannabis can be effectively harnessed through hemp. As hemp contains less than 0.3% of THC by weight, it lacks the intoxicating properties seen with marijuana.
Hemp is one of the strongest natural fibers on the planet. Mankind has been using it for many decades now as a building material.
More recently, hemp was discovered as a potent immunostimulant. The CBD chemical compound found in hemp can act as antioxidant, anti-microbial, anti-epilepsy and anti-cancer agents.
Furthermore, hemp has a very high nutritional value as it provides healthy fats as well as a range of different vitamins and minerals.
Hemp oil is extracted from hemp seeds and is added to cosmetic products, including: moisturisers, shampoos, and conditioners.
Before exploring the intrinsic physical, chemical and therapeutic properties of hemp and marijuana in further detail, let’s consider a brief overview of marijuana as well.
Table of Contents
- What is Marijuana?
- Hemp vs Marijuana
- Side Effects
What is Marijuana?
To reiterate, marijuana is defined as varieties of Cannabis with a total THC content greater than 0.3%. Mostly, C.sativa and C.indica varieties are exploited to produce marijuana. 
Marijuana generally, showcases a THC content in the range of 5 – 20%.  The intoxicating properties of THC are hugely amplified in marijuana as opposed to hemp.
Marijuana is the most widely used drug to create a pleasant feeling of a ‘high’ around the world. 
THC instills its psychostimulating effects by influencing the endocannabinoid brain signaling system. The chemical moiety can alter the sense of time, space and self.
Individuals under the influence of marijuana are likely to suffer from short term memory loss, impaired learning, and thinking.
With all these disadvantages in place, why is marijuana still the most popular drug around the world?
It is mainly due to its ability to provide changes in mood amongst users, which helps them relax, be friendlier and more social. 
Hemp vs Marijuana
Here we compare the physical and chemical properties of hemp and marijuana as well as their health benefits, drawbacks and side effects.
Hemp fibers are predominantly used in the textile industry. 
They provide high moisture absorbability, low heat loss from the body in cold climates, protection from UV radiation and some anti-bacterial properties.
Marijuana is made from the flowers of Cannabis sativa. Hemp products can be made from different parts of the plant.
For example: the fibers are used for textiles, paper and construction materials. The seeds are processed to make dietary hemp supplements and hemp oil.
Hemp and marijuana both impart their effects via the endocannabinoid system in humans. CBD does not bind to traditional endocannabinoid receptors: CB1 and CB2. 
Rather, most studies find CBD to influence the actions of anandamide – a cannabinoid signaling messenger in humans.
Marijuana induces a high by propagating dopamine release. 
THC can disrupt activity in the brain areas responsible for memory, pleasure, thinking, concentration and movement.
The Arizona Center for Integrative Medicine recommends hemp oil supplements to pregnant women for their daily omega-3 intake. 
Experimental analysis suggests there are more than 60 different cannabinoids (including CBD and THC) in both hemp and marijuana. 
Initial clinical evidence suggests that even small doses of CBD can improve alertness.  Marijuana imparts soothing and relaxing effects. It weakens alertness and reflexes.
CBD can weaken tumor aggressiveness and alleviate the unwanted side effects of conventional cancer therapies.
CBD treatment allowed 92% of breast cancer patients in a clinical trial to experience slowed tumor growth and impaired spread of cancerous cells from the primary site of infection to secondary sites. 
CBD can block oxygen and nutrient supply to tumors. Deprivation of oxygen eventually leads to death of cancer cells. 
A clinical trial with 48 leukemia patients found CBD reduced the likelihood of patients developing more severe forms of leukemia and lowered relapse rate. 
Hemp oil contains the antioxidant chemical: tocopherol. This compound protects from oxidative damage of DNA in colon cancer. 
The ideal 3:1 ratio of omega-6 to omega-3 fatty acids in hemp oil could reduce the risk of developing prostate cancer.
Prostate cancer is much more prevalent in the USA in comparison to Asia.
A typical Western diet was found to have a 46:1 omega-6 to omega-3 ratio whilst, Asian diets have a 3:1 ratio. 
However, further research is needed to identify the best dosage as 20 to 40 mg/kg can worsen vomiting. 
THC can enhance the production of human proteins, which are able to slow down tumour growth. 
THC stimulates self-automated death of cancer cells via specific cellular signalling pathways.  Seen in cell studies of melanoma, breast carcinoma, and prostate carcinoma.
Several studies highlight that the concentration of THC used must be carefully controlled otherwise it could produce pro-cancer effects.
One of the first clinical trials with glioblastoma cancer patients found THC to show some evidence of reducing tumour growth rate in all 9 individuals. 
When THC was co-administered with the conventional chemotherapy drug, Temozolomide, anti- tumour effects were strengthened. 
This was seen in mice models and no toxicity was produced.
Further clinical trials are needed to ensure marijuana is safe and effective for use by cancer patients.
THC capsules such as, Marinol, are commercially available to treat side effects of chemotherapy patients. 
Can Provide Pain Relief
THC takes only 20 to 30 seconds to reach the brain after being inhaled.  It can provide instant relief to individuals suffering from chronic pain.
A clinical trial found that as THC dosage was increased, cancer patients reported better pain relief. 
Sativex, an oral spray with 1:1 ratio of THC to CBD is available in the market to treat muscle stiffness and spasms in Multiple Sclerosis patients. 
Sativex was approved after multiple clinical trials produced results in favour of marijuana.
One example is a 1997 100-patient trial where every single patient reported that marijuana helped reduce muscle spasms and alleviate muscle pain. 
CBD provides neuroprotection and can reduce muscle spasms in patients. 
A 2017 clinical trial published in the prestigious New England Journal of Medicine found that the frequency of seizures plummeted from 13/month to 6/month in CBD-treated Dravet syndrome patients.
Similarly, CBD allowed a 50% reduction in seizures per month in a 171-patient Lennox-Gastaut clinical trial. 
CBD can reduce seizures by regulating hyperexcitability and calcium ion release in brain cells. 
A major milestone was achieved in June 2018 when hemp-derived CBD oral supplement, Epidiolex, was approved by the US FDA for reducing seizures in Dravet syndrome and Lennox-Gastaut syndrome. 
Since CBD has come into the spotlight, THC is less researched in the context of epilepsy. Additionally, most studies have found CBD to be more effective at reducing seizures than THC. 
A 2019 clinical trial published in The Permanente Journal found CBD oil supplements to reduce anxiety in 80% of the participants within just one month. 
Mostly, whole-plant marijuana has not shown anti-anxiety effects. Rather high doses of THC may increase risk of panic attacks. 
Hemp has not shown any significant potential in this illness.
Marijuana is mostly used by HIV and AIDS patients to increase appetite. In addition, marijuana can help with nausea, vomiting, sleep deprivation, pain, depression, and tiredness. 
Over the years, multiple clinical trials have ruled in favour of marijuana. As a result, THC capsules such as, Marinol, are commercially available for treating weight loss (anorexia) in AIDS patients. ,
Suitability for Neurodegenerative Diseases
Hemp-derived CBD can provide protection from radicals and reactive oxygen species, which accelerate brain damage. 
THC in marijuana leads to loss over movement control and distortion of time and space. Regular ingestion of THC can worsen short-term memory. 
Intoxicating effects of THC make it significantly less suitable for treating dementia-related diseases. 
Uniquely high arginine amino acid quantity improves blood flow and maintains normal blood pressure. 
The vast majority of research finds marijuana detrimental to heart health. Marijuana can raise resting heart rate, widen blood vessels and make the heart work abnormally faster. 
THC is a more robust anti-obesity agent than CBD. Rather than reducing food intake, THC increases how much energy is spent by the body. 
Hemp is a more superior source than the marijuana of essential fats i.e. those which the body cannot produce by itself.
Protecting From Cell Damage
Hemp-derived CBD oil is a stronger antioxidant agent than both vitamin C and vitamin E.
Skin culture studies found hemp oil provided protection from both UVA and UVB rays. Although most sunrays are UVA, both have the capacity to induce skin cancer. 
THC can exert mild anti-oxidative effects in the brain. However, how useful these effects are in front of the intoxication from marijuana is questionable. 
The scientific research behind the anti-oxidant and anti-inflammatory effects of marijuana is conflicted. A cell culture study found THC to exert good anti-oxidative behaviour. 
On the other hand, a 2016 clinical trial found marijuana smokers to showcase increased levels of pro-inflammatory molecules in the body. As well as, weakened natural anti-oxidative mechanisms. 
The only hemp is suitable for this. CBD can counteract the release of cytokines – inflammation-inducing chemical compounds. 
A study done under Project CBD found CBD to suppress pro-inflammatory responses from T-helper cells. These responses are used to signal to other immune system cells that the body is under attack. 
Hemp oil imparts anti-inflammatory activity by increasing oxygenation and blood flow to the skin.
Skin and Hair Care
CBD, omega-3, omega-6 and vitamin E are the most important chemical constituents of Cannabis for providing skin and hair care.
Although marijuana varieties of Cannabis offer these compounds, they come at the expense of the intoxicating effects of marijuana.
With not a single doubt, it can be stated that hemp is much superior to marijuana for skin and hair care.
The antioxidants in hemp regulate oil build-up in acne and may boost skin rejuvenation in sunburns, dermatitis and lichen planus. 
Hemp oil protects from dry skin by controlling abnormal water loss. 
The omega-3, vitamin E and beta-carotene in hemp can deeply moisturize dry skin and help alleviate itching of the skin and scalp. 
In 2017, a hemp oil conditioner was patented on the basis of providing protection from alopecia. It can nourish hair from the roots and eliminate inflammation-causing microbes.
A very recent 2019 clinical trial published in the reputed Nature journal, found commercial hemp oil products to boost hair growth of participants within just 6 weeks. 
The products enhanced glossiness and smoothness of the hair whilst, reducing hair loss significantly.
Nowadays, hemp oil is listed alongside the traditional coconut and almond oils for hair benefits.
Hemp oil proteins could be used to build collagen. Collagen can improve the elasticity of hair so that, it feels lighter on the head and is more resistant to breakage. 
Vitamin E in hemp protects the cells providing color to the hair can and thus, greying can be prevented for longer. 
Unlikely to showcase any effects on the memory of an average individual consuming or topically applying hemp products.
Dravet Syndrome patients ingesting CBD suffered from side effects like: vomiting, diarrhea, fever, and fatigue.
Epidiolex can induce side effects like: sleepiness, insomnia, decreased appetite, diarrhea, fatigue, and mild liver injury.
CBD is non-toxic to humans even at doses up to 50 mg/kg. 
THC is needed to develop an addiction. The quantity of THC in hemp is insufficient to allow addiction.
Regular use can cause short term memory loss. Unable to think effectively i.e. individuals under the influence of marijuana are much more likely to be involved in vehicle accidents.
The possible side effects or Sativex include dizziness, drowsiness, constipation, diarrhea, fatigue, lack of concentration and dry mouth.
It is not advisable to drive cars or operate machines when you first start taking Sativex.
Individuals under the age of 18 are 7 times more likely to develop addictions than adults.
Although medicinal marijuana is being more approved around the world, it can increase cardiovascular risk, especially in individuals with pre-existing heart conditions.
Hemp and marijuana are varieties of the same group of plants – Cannabis.
The chemicals compounds found in Cannabis are more valuable when coming from hemp as they are not infected by the intoxicating agent, THC, which is found in marijuana.
Since CBD and hemp have been discovered, marijuana is less preferred for therapeutic use.
However, medicinal marijuana is still the more preferable option for treating chronic pain, specifically in multiple sclerosis patients. Marijuana can help alleviate symptoms of HIV and AIDS.
Hemp completely outweighs marijuana when it comes to cancer, epilepsy, cardiovascular health, skincare, hair care, and neurodegenerative diseases.
Hemp is a proven anti-oxidant and anti-inflammatory agent. Whilst, marijuana is unlikely to provide these desirable qualities.
The side effects of hemp are minimal and it’s highly unlikely to cause any toxic reactions.
The generous quantity of THC in marijuana means it must be tightly regulated when being prescribed to patients as it can significantly impair brain and heart health.