How long does THC oil last?

Patients who have just received their first cannabis oil prescription may wonder how long their medicine will last. This is a great question – let's delve in to understand just how effective a prescription will be after certain periods of time…

People with a diagnosed health condition and long-term medical diagnosis may take THC oils to treat specific symptoms, but not everyone administers them at the same rate. Each person's endocannabinoid system is different, which means that we all react at least slightly differently to the same dose size. Your tolerance to THC will be different from others, and this means working out exactly how long that bottle of THC oil will last can be a little tricky.

So how long does THC stay active once the bottle has been opened? Let's have a look at some ways THC can be extracted from the plant and how it can be prepared to understand this important question.

THC in focus

Delta 9 Tetrahydrocannabinol, more commonly referred to as THC, is the resinous, sticky substance that offers some of the possible medicinal qualities, and also the psychoactive effects that cannabis is well known for. THC is prescribed in the UK for a range of health issues, and this includes controlling pain, aiding in sleep, as well as increasing appetite. It's often taken by patients experiencing symptomatic issues relating to muscle spasticity, glaucoma, HIV/AIDs, and Crohn’s Disease.

THC is just one cannabinoid found in cannabis, although it is typically the most abundant (this is strain dependent, of course). During the growing process, the cannabis plant biosynthesises Cannabigerolic Acid (CBGA). CBGa is converted into Tetrahydrocannabinolic Acid (THCa) or Cannabidiolic Acid CBDA via a synthase process, depending on the plant's genetic coding. THCa decarboxylates (a process where the THCA molecule loses a CO2 molecular bond) resulting in THC. When THC is exposed to unfavourable conditions it turns into Cannabinol (CBN) which is slightly less psychoactive and analgesic, but studies are showing that it may offer a stronger sedative effect, with anecdotal evidence also pointing to it being more appetite-stimulating. THC converts into CBN when it is exposed to heat, pressure, or oxygen.

For some patients, cannabis can be most beneficial when taken in the form of an oil. Cannabis oil products can be carefully dosed and paired with a specific ratio of CBD to deliver a more tailored cannabis-based medicinal product (CBPM). This can then better meet the individual patient's needs… As of now, there are very few CBPMs that are authorised for administration for specific diagnosis with GW Pharmaceuticals sublingual spray Sativex for MS spasticity and Epidyolex sublingual tincture for Dravet’s Syndrome, a rare form of epilepsy being the only two available for prescription right now in the UK.

Getting started with THC oil

To make THC oil, the first step is to separate the active compounds from the plant material using an extraction process. There are a number of different extraction methods that can be used to achieve this. 

Supercritical CO2 extraction is a method that harnesses the power of high-pressure carbon dioxide gas and blasts it over the plant material that is packed into a chamber. This same method is used when extracting THC and other active compounds with hydrocarbons such as butane, which leaves a product known more commonly as BHO or Butane Hash Oil.

The difference between a hydrocarbon extraction (solvent extraction) and a CO2 extraction (solventless extraction) is that the solvent must be removed from the end product with BHO. Vacuum purging equipment is used to remove the solvent from the end product in order for it to be pure and meet safety standards. 

Stripping the plant material of all cannabinoids can also be attained by soaking it in a high or pure alcohol/ethanol solution. Once this process is complete, the solution needs to be filtered using a fine-micron screen to make sure no plant matter is left. The ethanol is then evaporated off, leaving the thick, sticky THC oil.

Cannabis trichomes can be mechanically separated using ice-cold water and bags with decreasing size micron mesh screens at the bottom. This product is usually known as bubble hash or ice water hash.

Once the extraction processes have taken place, the THC and other cannabinoids are in a concentrated form that is referred to as “full-spectrum”. It contains a mixture of most of the active compounds found in the original cannabis flower including cannabinoids, terpenes, flavonoids, esters, fats, waxes, and lipids. Ideally, the fewer fats, waxes, and lipids that are extracted the better – as these are considered pharmaceutically inactive compounds which weaken the purity of the oil. These can and will be removed from all medicinal cannabis oils before reaching the patient's hands. 

Storing THC oil for longevity

A concentrated full-spectrum oil can have a shelf life of two to three years. If stored in airtight and cold conditions this may extend the shelf life to over three years and if frozen, potentially longer. If the THC oil is not stored in cool conditions, or it is exposed to air, it will oxidise, losing some of the terpene profile and degrading the THC over time, weakening the potency. 

Full-spectrum, undiluted THC oil concentrates that are incorrectly stored will last between six months and a year, degrading at least somewhat rapidly month by month.

When a full-spectrum THC oil is diluted with a carrier oil and put into a tincture bottle or capsules, there are multiple factors that will have a beneficial result on the shelf life and longevity of the product. These factors revolve around the storage conditions of the cannabis-based medicinal product. Because the THC oil is suspended in a carrier oil, the shelf life of the carrier oil needs to be taken into consideration, as the THC will only last as long as the carrier oil remains unchanged.

Seed oils have the tendency to go rancid if they are not correctly stored. When seed oils turn, it has a detrimental effect on the quality of the product. The taste is compromised and becomes unpleasant, more bitter and slightly foul-tasting and smelling. Rancid oils can deplete the body of vitamin B and cause gastrointestinal issues. This does not necessarily mean that the THC has degraded, but seed oils that have gone off are no longer considered safe for administration. Storing your tinctures in a cool place and not allowing them to be exposed to heat is very important.

A tincture will have a shelf life of around one year if stored in ambient temperatures that do not exceed 21 degrees Celsius. If stored in cooler conditions, this could push the shelf life span up to 18 months.

The same rule applies to THC cannabis oil capsules if they are made using seed oils as the carrier. Store in a cool place and do not expose to heat. Keeping them in an airtight container in the fridge away from moisture will ensure the longest shelf life span for all CBPMs.

Don't let the stigma surrounding medical cannabis prevent you from getting a suitable treatment. Releaf provides tailored monthly packages, specialist consultations for medical cannabis, and a unique medical cannabis card for protection, all based on your medical cannabis prescription.