Smoking and vaporising
Smoking is by far the most popular method for using cannabis, particularly when used for recreational purposes, though does also have medical applications to it. The main appeal to smoking cannabis is the near instant effect felt from inhaling the activated cannabinoids.

Effects from smoking cannabis can be felt within seconds and this makes it very easy to accurately dose for desired effects. It also makes it especially useful when cannabis is used to relieve symptoms as relief is near immediate. Though smoking is not an efficient way to saturate the body with cannabinoids, which is often necessary when attempting to directly treat diseases like cancer and MS, it is by far superior as a fast acting reliever of various symptoms.
Vaporising is a more efficient method of consuming cannabis through the lungs and a more healthy method as it involves the vaporising of cannabinoids without the harmful hydrocarbons present in smoke. Also the combustion involved in smoking cannabis means that many of the cannabinoids are destroyed and lost whereas vaporising avoids combustion which means that none of the cannabinoids are destroyed and no harmful chemicals, found in smoke, are present in the inhaled vapour.
However, while destruction of cannabinoids is avoided when using vaporisers it is difficult to remove all cannabinoids from the plant material this way and THC, CBN and other cannabinoids often remain trapped in the plant material, which is often discarded after use. More expensive vaporisers are more efficient at stripping the cannabinoids from the plant material, and efficiency can be further increase by grinding cannabis prior to vaporising. In addition to this, better vaporisers often have more accurate adjustable temperatures which allow users to be more selective over which cannabinoids they prefer to consume, as different cannabinoids vaporise at different temperatures, as do the various terpenoids.
Both smoking and vaporising is essentially consuming cannabis through the lungs. As the cannabinoids are absorbed through the lungs they are instantly sent to the brain via the heart, bypassing all other organs. As a result of this fast delivery method to the brain the psychoactive effects of THC is felt within seconds and the therapeutic effects are felt very quickly. Pain relief, anti-nausea and anti-spasmodic effects are felt within seconds. The appetite stimulation may take a little longer, with some increase in hunger observed within 10 to 20 minutes and larger more intense hunger usually observed within an hour.
The heat involved in smoking or vaporising cannabis causes instant decarboxylation of the cannabinoids so decarboxylation of cannabis prior to smoking it is not necessary as all raw cannabinoids, like THCA, will convert to their neutral counterparts, like THC, immediately. In fact when used for smoking or vaporising many people prefer their cannabis to be raw as the heat involved in achieving full decarboxylation involves a loss of many of the terpenoids. Because of this raw cannabis, when smoked or vaporised, is considered to have more flavour to it than cannabis that has already gone through decarboxylation.
However, another consequence of this instant decarboxylation caused by smoking or vaporising cannabis is that you cannot consume the raw cannabinoid acids using these methods, as any cannabinoid acids present in the raw material will be instantly converted to their neutral counter parts from the heat involved.

As more of the medicinal activity of cannabis is being revealed ingestion is fast becoming a more widely used method of consumption. Eating or drinking cannabis is a better way of saturating the body with the necessary doses for actually treating a specific condition or disease for long term benefits.
Though eating heated cannabis will provide similar symptom relief, along with the high, associated with smoking or vaporising, it does take much longer for the effects to be felt. This makes specific dosing very difficult for many patients.
The psychoactive effects of THC are felt almost instantly when smoked or vaporised yet eating cannabis will usually not create psychoactive effects for anywhere between 40 minutes and 2 hours. The exact time it takes to feel the effects of ingested cannabis varies depending on a variety of factors, including whether it is taken with food and the fat content of the food.
Since the revelation of many of the medicinal properties of cannabis the most popular form to ingest cannabis is in the form of cannabis oil. Though mixing cannabis into edibles like cakes and cookies has long been popular.
When ingesting cannabis, decarboxylation becomes an important factor. Cannabis in its raw form is mostly cannabinoid acids as opposed to the neutral/”activated” cannabinoids. In its raw form the cannabinoid acid precursor to THC is THCA. THCA does not have psychoactive effects so can be consumed in very large doses without the user feeling the high associated with THC. Raw cannabis also tends to have a larger quantity of terpenoids, many of which are lost when cannabis is cooked for decarboxylation.
Some medical conditions do respond favourably to raw cannabinoids like THCA and CBDA, as well as the naturally present terpenoids. However the vast majority of the established therapeutic properties associated with cannabis are involving the neutral cannabinoids, so to utilise those properties it is essential that cannabis meant for ingestion is properly cooked to achieve full decarboxylation, converting all the cannabinoid acids like THCA, CBDA and CBCA to their neutral counterparts, THC, CBD and CBC.
There is debate over whether raw is medicinally better or whether cooked is, or if a partial decarboxylation is preferred which would provide a combination of raw cannabinoid acids, neutral cannabinoids and most of the naturally present terpenes. Though for the purposes of precise doing the utilisation of both raw and cooked cannabis would be better suited to making a fully raw and a fully cooked extract and simply taking both, as a partial decarboxylation is hard to gage without access to lab testing facilities to confirm exact ratios of neutral and acidic cannabinoids.
Proponents of raw cannabis point to the loss of nutrients, terpenes and cannabinoid acids during the cooking process and claim that the potential of raw cannabis is heightened further by the lack of psychoactive effects which allows the user to consume much larger quantities. There is also a belief that cannabinoid acids are medicinally superior to neutral cannabinoids on a one to one basis, however this is not supported by the evidence and in the case of THCA and THC actually runs contrary to the available evidence that strongly suggests that THC is far more medicinally active and potent than THCA, especially when fighting things like cancer.
Proponents of cooked cannabis point to the abundance of evidence for the “activated” cannabinoids which vastly dwarfs the comparatively modest amount of evidence supporting the therapeutic value of raw cannabinoid acids.
While the inferior quantity and quality of evidence supporting the medicinal activity of raw cannabinoid acids does not necessarily prove it to be an inferior medicine, as many raw proponents will point out that the lack of evidence is paralleled with a lack of research, there are legitimate reasons for considering raw cannabis to be less potent as a medicine than properly cooked cannabis, especially when treating things like cancer. For example, the cancer killing properties of THC primarily involve the activation of the two main cannabinoid receptors CB1 and CB2. In addition to being unable to pass the blood brain barrier in its raw acidic form, THCA cannot activate either the CB1 or the CB2 receptor. As a result of this raw THCA is unable to kill cancer cells through this pathway and any anti-cancer effect it does exert would have to be through other pathways. Many of the established therapeutic effects of THC are through the activation of CB1 and CB2 receptors. As THCA cannot activate these receptors it cannot be assumed to exert the same medicinal properties. There is no doubt that THCA does have its own therapeutic effects, as do the other acidic cannabinoids like CBDA, CBGA and CBCA, which are exerted through other pathways but many of its medicinal properties are less established and less understood than those of THC, CBD, CBC etc.
Raw Cannabinoid acids, like THCA and CBDA, do modulate the Endo Cannabinoid System and the immune system through other pathways, affinity with COX-1 and COX-2, TRP channels like TRPM8 and TRPA1 from CBDA and THCA and observed effects on GPR55 from CBDA and CBGA are all examples of this, and many therapeutic effects have been established, including neuroprotective and anti-inflammatory effects.
There is a widely held belief that raw THCA does have its own anti-cancer effects which utilises other pathways independent of CB1 and CB2, which could potentially make THCA a useful supplement for treating cancer and even keep alive the hope that it may be utilised as a standalone treatment for some types of cancer when better understood.
However at this time the perceived potency of raw THCA as a cancer fighting substance is nowhere near the potency of THC and it appears that raw THCA would be far less effective, if effective at all, as THC clearly is for treating cancer.
There is currently a similar disparity between raw CBDA and CBD. While CBDA does have some established properties, including some established anti-cancer effects, its proven medicinal properties are not as abundant, established or perceivably potent as CBD. This is currently the case when comparing all cannabinoids with their raw acidic precursors. Across the board it is the neutral cannabinoids like THC, CBD, CBC, CBG and CBN which have far greater and more established therapeutic effects than their acidic precursors, like THCA, CBDA, CBCA, CBGA, and CBNA. Raw proponents may claim that this is merely a result of the greater attention given to the neutral cannabinoids, and while this is technically true such an argument can be countered by pointing out that the reason the neutral cannabinoids have been given more attention is because the preliminary research has demonstrated greater medicinal promise than that of the raw cannabinoid acids. Though it could also be noted that another factor in the disparity is the fact that cannabinoid acids are newer in discovery and as many testing involved heat that causes decarboxylation it was often the neutral cannabinoids that were tested rather than the raw cannabinoid acids.
It cannot be ruled out that raw cannabinoid acids may be proven to have greater value for some conditions than the neutral cannabinoids, but based on the current evidence it is the neutral cannabinoids which are therapeutically superior for virtually all conditions, with the possible exception of some inflammation related disorders. Already anecdotal evidence is building that raw THCA may be superior to THC for treating epilepsy and even some reports from patients who claim it do be more effective than CBD. However a distinct lack of clinical research into this keeps such claims purely in the realms of anecdotal evidence, and even anecdotally this claim lacks sufficient evidence to be deemed an established fact.

Regardless of whether it is raw cannabis that you wish to consume or cooked cannabis it is vital that decarboxylation is well understood. Smoking and vaporising causes full and an instant decarboxylation so consumption of raw cannabinoid acids is not an option for smokers and vaporisers. However when ingesting cannabis the amount of decarboxylation is essential as no decarboxylation occurs within the body. When it comes to cannabinoids what you ingest is what you get.

Ingesting raw cannabinoid acids is done through either juicing fresh plant material or extracting oils using cold extraction methods, like BHO (Butane Honey Oil). While rapid decarboxylation requires high temperatures (110c to 130c for full decarboxylation within an hour) gradual decarboxylation can occur in dry material or extracts at room temperature. So it is recommended to avoid any heat in preparing raw cannabis juices or oils and to store these preparations in the fridge or freezer.
Ingesting activated cannabinoids is done through cooking cannabis. Many oil making methods like RSO (Rick Simpson Oil) will involve some partial decarboxylation from the heat involved in boiling off the solvents, however additional cooking is often required to complete full decarboxylation. Similar care is needed when attempting to achieve full decarboxylation for edibles, like cakes, cookies and cannabutter (cannabis butter) as the cooking times and temperatures involved in making many cannabis edibles may only be sufficient for a partial decarboxylation.
While exact decarboxylation times and temperatures do vary depending on other factors (prior decarboxylation achieved through drying of plant material, quantity, quality and what form the cannabis is in, dry plant material will decarb quicker than oil while wet plant material will take much longer for decarboxylation to be achieved) the optimum decarboxylation time and temperature is usually considered to be between 110 and 130 degrees Celsius for between 30 minutes and an hour.
Decarboxylation of cannabis meant for ingestion is important for maximising THC content, along with other “activated” cannabinoids like CBD, CBC etc. While maximum THC content is primarily a concern for recreational users looking to maximise the high they get from the minimum amount of cannabis it is also potentially vital for therapeutic effects, especially when treating cancer as THC is by far the most potent cancer killing cannabinoid, based on current data.
The primary difference between eating cooked cannabis and smoking or vaporising cannabis is the time taken to feel the effects, with smoking and vaporising providing relief within seconds while eating can take between 40 minutes and 2 hours. However there are other differences worth noting. Because consumption through the lungs sends cannabinoids directly to the brain in a more direct manner it often requires a smaller amount to feel psychoactive effects. However the intensity and duration of the psychoactive effects is limited through inhalation as the brain has various mechanisms for limiting the psychoactive effects and the duration of the high will not exceed 4 hours when cannabis has been consumed in this way.
When eating cannabis, because of the less direct pathway to the brain, which also accounts for the greater amount of time required to feel the high effect of the THC, more is usually required to feel the minimum high effect. While a couple of puffs of a cannabis joint while give most users a noticeable psychoactive effect the same quantity of THC ingested will likely not give users any noticeable effect (even if full decarboxylation is achieved) as much of the THC will not make it as far as the brain as it is absorbed into the body along the way. Also tolerance can be built up quicker and easier with regular ingestion and as a result even more is required to feel the high effects.
However ingesting cannabis can result in longer lasting and more intense effects if you consume sufficient amounts. There are two main reasons for this. One reason is that while smoking provides an instant delivery of THC to the brain, eating it results in a more gradual drip feeding of THC to the brain which can spread out over a longer period of time. Another factor is that much of the delta 9 THC from the plant is converted by the liver into another kind of THC called 11 hydroxy THC which is considered to be about 4 times more potent and more psychoactive. A factor common among more novice users of cannabis, when eating it, is over consumption of cannabis. When people smoke or vaporise cannabis they feel effects immediately so can simply stop smoking or vaporising when desired effects are achieved. But because eating cannabis does not give instant effects many people will consume more than they need to, unaware that they are consuming more than needed.
As a result when the high effect does hit them they have already consumed more cannabis and can do nothing to stop the THC that they have already consumed going to their brain. This, combined with the more potent 11 hydroxy THC produced by the liver, results in a more intense high which can last for many hours, even days and can be a scary experience for novice users. There is no physical danger from consuming too much THC and those who eat too much are advised to sleep it off if possible or consume coffee and black pepper to attempt to mediate the effects of the THC. But nonetheless, over consumption of cannabis through ingestion can create undesired effects so caution is advised, despite the lack of toxicity.

Another method ideal for medicinal use, this method is preferred by people who need to saturate their body with cannabinoids but struggle with the psychoactive effects of the THC through ingestion. It is still possible to get high through this method but suppositories put the THC directly into the blood stream without going through the liver, so the conversion to 11 hydroxy THC is avoided. THC administered through suppositories also passes through more of the body before reaching the brain than if smoked or vaporised and is considered ideal for treating cancers that are close to that area, like prostate cancer for example, and is perhaps surprisingly effective against lung cancer. A popular method is to mix cannabis oil with coconut oil or coco butter, though it can be be administered on its own in suppositories. Because of the lower psychoactive effects and the efficiency in which cannabinoids are absorbed, allowing for larger doses to be administered, suppositories are becoming a more popular method for those who wish to utilise the therapeutic benefits of THC with out too much of the psychoactive effects. This is especially useful for many cancer patients who need to saturate their bodies with large and regular doses of activated cannabinoids.

Topical applications
This method is pretty much only applicable for medicinal use as getting high through topical applications is unlikely. Cancers that are visible, like skin cancers or tumours that have either broken through the skin or have caused visible lumps through the skin are best treated with topical applications, though internal administration like ingestion and suppositories is still recommended in addition to topical applications.
When it comes to topical applications both raw and cooked cannabis oils have demonstrated efficacy and many patients have reported success treating cancers and various other insults and skin conditions, like burns, warts, eczema and various rashes. Generally speaking decarboxylation is recommended for oils used for topical applications, partially because they are considered to be more effective, partially because raw oils tend to be less oily in consistency, often hardening to the point that smearing it is impossible without warming it slightly and partially because the advantage of a lack of psychoactive effects from raw extracts is irrelevant as topical applications are unlikely to result in any high effect being felt even when oil is psychoactive to ingest.
To make oils easier to apply cannabis oil is often mixed with another oil like coconut oil or butter, olive oil or hemp seed oil. A slight heating of the oils is often advised to help the cannabis oil bind to and mix with the other oils, though cold infusions are possible.

Ingestion, inhalation, suppositories and topical applications are the main ways to consume cannabis. And without medical assistance these are the only feasible ways to consume cannabis. Purified extracts and isolated compounds can be injected directly into the blood stream by a doctor and pure THC has been injected directly into cancerous tumours in experimental situations as a method of administering the maximum THC to the tumour with minimum THC available to cause psychoactive effects. However intravenous use of cannabis is not something that can be utilised without medical supervision and administration and injection of cannabis oil, no matter how well made, should not be attempted under any circumstances.
Cannabinoids in cannabis are remarkably non-toxic and while too much THC can lead to undesirable psychoactive effects there is not any risk of physical damage or harm from cannabis and a fatal overdose of cannabis, raw or cooked, is considered physically impossible. However consuming too much THC can cause undesirable effects and is particularly likely when eating it due to the long delay in the onset of the psychoactive effects. So when consuming edibles caution is recommended simply for the purpose of avoiding unpleasant effects.
When it comes to medicinal use, the means of administration are important and often multiple methods well be employed to maximise efficacy. As with other important factors like decarboxylation, dosing, strain selection and form, the method of administration of cannabis medicines can be important for making the most of this medicine.