There's some positive evidence.
by Kelly Rush
Reviewer Binoj Joseph Matthew, MD, MHA– August 29, 2019
Skincare products have hit the market recently with claims of treating everything from acne to psoriasis, or just contributing to that healthy glow.
Research shows the psychoactive cannabinoid in marijuana, THC, does have anti-inflammatory properties that could benefit the skin when applied topically, and has shown promise as a potential treatment for conditions such as psoriasis.
But, at this point in the game, it may be still too early to say conclusively that marijuana skin creams and products work, but there is some positive evidence.
THC and Itchy Skin
One research team, from the University of Colorado Anschutz Medical Campus, pored over the available literature on cannabinoids and skin diseases.
“Perhaps the most promising role of cannabinoids is in the treatment of itch,” said the study’s senior author Dr. Robert Dellavalle in a press release.
In one of the studies the team reviewed, eight of 21 patients who applied a cannabinoid cream twice a day for three weeks completely eliminated itching.
The team also found evidence that THC reduced swelling and inflammation in mice.
A drug called dronabinol, made from synthetic THC has also shown some promise when it comes to chronic itchy skin, according to a 2018 review looking at cannabinoids’ role in dermatology.
The FDA already approved dronabinol for some conditions, including weight loss and nausea and vomiting associated with cancer chemotherapy. Still, the evidence in this case was slim, the review noted.
CBD and the Skin
Of course, THC isn’t the only cannabinoid researchers are scoping out as a potential skin treatment. CBD, the other common non-psychoactive compound in marijuana, is cited often as a potential therapy for inflammatory skin disorders.
One such study, published in 2019, involved 20 patients with either psoriasis or atopic dermatitis and some who had scars from the disorders. The patients applied a CBD-rich ointment to skin areas twice a day for three months.
Results showed that the ointment significantly improved the skin, while no allergic reactions were reported. The research team concluded that CBD ointment, without any THC, could be an effective alternative medication for these conditions and could improve patients’ quality of life.
Considering the well-known anti-inflammatory properties in cannabis’ most common compounds, it is not surprising the drug has potential for treating eczema, as well as symptoms of pruritis (itching) and some other common skin problems.
In fact, one of the founders of American Dermatology, Dr. Henry Granger Piffard, reported 50 years before cannabis was outlawed, and while penning the first textbook of dermatology stated,
“ A pill of cannabis indica at bedtime has at my hands sometimes afforded relief to the Intolerable itching of eczema.”
Unfortunately, cannabis’ legal status has prevented a lot in terms of medical research. Until we have more long-term, high-quality clinical trials, we can’t say whether THC or cannabis topicals will become your go-to skin therapy of the future.
The Endocannabinoid System in Your Skin
We’ve known about the body’s endocannabinoid system for some time and the role it plays in regulating the central nervous system and immune functions. The cannabinoids in marijuana, including THC, mimic natural endocannabinoids the body produces which are involved in everything from pain and memory regulation to how well we sleep.
Scientists previously thought cannabinoid receptors existed only in the brain and nerves, but later discovered they were dispersed throughout the whole body, including in the skin.
Over the last two decades, researchers have confirmed that cannabinoid receptor signaling is involved in a lot more than we realized when it comes to the skin, including skin regrowth. Problems with the system could result in diseases ranging from:
- Hair growth issues
- Keratin disease
On the positive side, THC shows promise in reducing allergic skin inflammation; on the other hand, we know that abusing synthetic cannabinoids like K2, which contain high levels of THC, can result in premature skin aging, hair loss and acne, which suggests cannabinoids can have a harmful influence on skin biology, according to a 2017 study.
One 2018 review cautioned that although medical marijuana has the potential to treat a number of skin conditions, including acne, much of the research on the subject is pre-clinical, meaning we have a lack of high-quality, controlled trials that evaluate the effects of marijuana’s compounds, including THC and CBD, on the skin.
Skin’s Function in the Body
The skin is the body’s heaviest and largest organ and makes up about one-seventh of our body weight. It’s not only a protective barrier, keeping out germs and toxic substances and regulating temperature, it acts like a cellar where the body stores important supplies such as water, fat and metabolic products.
A lot of skin problems, including eczema and psoriasis, involve inflammation, which can be triggered by a wide variety of causes. Some types of inflammation are triggered or worsened by allergies.
In the case of eczema, also known as atopic dermatitis, the skin barrier is thought to have a “leakiness” problem where it dries out and inflammation is triggered by environmental factors. The condition is also linked to hay fever, asthma and food allergies, according to the American Academy of Allergy, Asthma and Immunology.
When topically applied, THC can reduce allergic flares by decreasing the role that keratinocytes play in triggering inflammation. Keratinocytes are skin cells that make up more than 90 percent of the cells in the epidermis. These cells also play a role in psoriasis, a condition where the body’s immune system goes haywire and white blood cells attack the body’s skin cells.
The attack causes the body to make extra cells, which pile up on the skin’s surface, according to the American Academy of Dermatology.
A 2007 study looking at cannabinoids and the skin found that THC could be a potential treatment for psoriasis as well.