Despite a lack of research, many patients are turning to cannabis oil to treat serious illnesses including cancer.

When most people think about marijuana, they might picture someone smoking a joint or eating a brownie. However, cannabis concentrates — specifically cannabis oils — are becoming increasingly popular among patients who are looking for a way to ingest cannabis in extremely high doses.

And while scientists are still wary of the lack of evidence supporting its safety and effectiveness, a growing number of patients are turning to cannabis oil in an attempt to treat themselves.

1. Cannabis oil is a highly concentrated form of cannabis

Cannabis oil is an extract made by mixing cannabis flowers with a solvent such as ethanol, naphtha, petroleum, or butane. The extraction process removes the plant matter and leaves behind a sticky, oily substance that contains a high concentration of active compounds.

Cannabis oil is mainly taken orally as a medicine for various conditions. When taken alone, the oil is usually administered to the patient using an oral syringe or dropper. However, cannabis oil can also be taken along with food or made into edibles.

“The big trend right now is ingesting it,” says Dr. Arno Hazekamp, a researcher with Dutch-based medical cannabis company Bedrocan BV who in 2013 conducted one of the only studies ever published on homemade preparations of cannabis oil.

Since cannabis oils contain a high concentration of cannabinoids – such as THC and CBD – most patients only require a small amount. Taking a small dose of oil provides the same effects as smoking or vaporizing a large quantity of marijuana flowers.

While the most potent strains of marijuana contain around 20% THC, highly purified cannabis oils can contain up to 80% pure THC, says Dr. Hazekamp.

But when it comes to purchasing cannabis oil, it’s difficult to know what you’re actually getting since many are labeled incorrectly, he warns.

“Whatever is on the label, you don’t really know if you can trust it,” says Dr. Hazekamp. He adds that products available for sale in the U.S. often contain different cannabinoid concentrations than what is labeled, and sometimes may not contain any THC or CBD at all.

2. There are many different types of cannabis oil

A common mistake that many people make is assuming that cannabis oil is just a single product. In fact, the term cannabis oil is commonly used to refer to a variety of different products.

“There’s no one thing that’s called cannabis oil,” explains Dr. Hazekamp, adding that scientists have a hard time studying the effects of cannabis oil due to the many different recipes that people use to make the product.

However, all cannabis oils seem to fall under two main categories: high-THC oils and high-CBD oils.

Cannabis oils that contain high levels of THC are perhaps the most recognized among medical patients. These oils include Full Extract Cannabis Oil (FECO) and the famous Rick Simpson oil (RSO). While THC oils can be found in many dispensaries, patients often choose to make their own at home by following various recipes that are available online.

There are also a number of high-THC oils that are used for recreational purposes. For example, Butane hash oil (BHO), shatter and wax are common names for oil-based marijuana extracts consumed in a process known as dabbing.

Finally, there are a variety of CBD-rich oils that do not contain any THC and thus do not have psychoactive properties. Like THC oils, CBD oils are typically taken orally by medicinal users, and have gained significant popularity as a treatment for epilepsy in children.

3. Patients are using cannabis oil to treat a variety of medical conditions

Cannabis oil has gained popularity in recent years due to the wide range of medical conditions that many claim it can treat.

While scientific proof is lacking, there are many reports of patients using cannabis oil to effectively manage conditions such as chronic pain, Crohn’s disease, asthma, arthritis, heart disease, multiple sclerosis, diabetes and, most notably, cancer.

Still, the lack of medical research on cannabis overall leaves Dr. Hazekamp — and many other scientists like him — skeptical of these claims.

“With cannabis, there’s different strains, there’s different administration forms, there’s different oils,” says Dr. Hazekamp. He adds that pharmaceutical research, on the contrary, is usually conducted using a specific active ingredient in a specific dose.

“The problem with all cannabis research is that there’s no coordinated effort.”

Compared to dried marijuana, the effects of cannabis oil are similar but amplified due to the higher concentrations of cannabinoids.

For inexperienced cannabis oil users, the high can be overwhelming, especially when taken in large doses.

CBD oil is also believed to have many medical uses ranging from the treatment of epilepsy and schizophrenia to anxiety and depression. A scientific review of 25 studies found that CBD did not have any significant side effects, regardless of dosage or administration method.

4. The popularity of cannabis oil began with Rick Simpson

While cannabis oil is now widely recognized, the oil first started to gain attention when a man named Rick Simpson claimed to have cured his own cancer in 2003 with a homemade recipe.

According to his website, Rick Simpson was diagnosed with metastatic skin cancer and decided to apply his own oil-based cannabis extract directly to the lesions of his skin. After only four days, the lesions disappeared and eventually his skin cancer was gone.

Since then, Simpson has been educating others on how to make and use cannabis oil through his website, which includes a step-by-step guide on producing the oil at home.

A documentary on Rick Simpson’s story called “Run From The Cure” was released in 2008 and helped garner much attention and support for cannabis oil as a cancer cure.

Since starting his advocacy on cannabis oil, Simpson claims to have helped over 5,000 patients treat various illnesses and diseases such as cancer, depression, arthritis, diabetes and more.

5. It’s not clear whether cannabis oil cures cancer

The evidence that cannabis oil can cure cancer is controversial and largely anecdotal. However, there is some research that seems to provide support for patients’ success stories.

In 2009, researchers found that THC had significant anticancer effects on human brain cancer cells. Furthermore, a 2013 report published in the Cancer Management and Research journal concluded that there is a “distinct possibility” that cannabinoids may be a part of future cancer treatment.

In 2015, the National Cancer Institute (NCI) updated its FAQs page to include several studies that show cannabis could be an effective cancer treatment.

But Dr. Hazekamp notes that while early-stage studies have shown that cannabinoids may have an effect on cancer cells, that doesn’t mean that it works the same way in humans.

“What science says is that some cannabinoids do have an effect on cancer cells, but it’s very unclear if that also happens in real humans,” explains Dr. Hazekamp.

“If you don’t put your cannabinoids directly on cancer cells in a petri dish, but you actually ingest it, does it reach the cancer, does it do anything there, is the concentration high enough? It’s not clear how the translation is from cells to animals to people.”

According to Dr. Hazekamp, the only research in humans comes from one small study conducted by researchers in Spain.

The study, published in 2006, involved nine patients with advanced glioblastoma multiforme, a terminal form of brain cancer with no cure. The patients were split into two groups and were given either a placebo or THC injected directly into the brain.

“In a one year period, everybody died but the people that had the cannabis treatment lived 4 weeks longer on average,” Dr. Hazekamp summarizes.

“That is the proof we have in people right now. So if anybody says cannabis can cure cancer and its scientifically proven, then this is the best proof in real humans that they have.”

On the other hand, while Dr. Hazekamp believes that researchers are many years away from providing evidence that cannabis oil can cure cancer, there still seems to be some merit in prescribing it for cancer patients.

“Cannabis definitely does work for things like appetite, sleep, pain, nausea, vomiting, mood and anxiety. So there’s a lot of things that are pretty well proven for cannabinoids,” says Dr. Hazekamp.

“So I think most physicians are pretty convinced that it’s useful for treating symptoms — but actually curing cancer, that’s a whole other level.”