Do cannabinoids from topicals enter the bloodstream?

Lorena Cupcake, voted “best budtender in Chicago” in 2019, has answered hundreds of questions from cannabis shoppers and patients during their time as a budtender. And now they’re turning that experience into a monthly advice column, Ask a Budtender. Got a question for Cupcake? Submit your questions to askabudtender@weedmaps.com.  

Dear Cupcake,

Do you know if cannabinoid-infused topicals, such as Papa & Barkley’s topical, go into your bloodstream? I’m asking for my sister who works for the government. She has a lot of physical aches and they want her to do surgery but she would rather experiment with different products.

— Concerned Sister

Dear Concerned Sister,

Before I answer your question, I want to cover a few points I hope we all agree with. Drug testing for cannabis and other drugs is wildly inaccurate, based on false premises and applied inequitably among members of the workforce. Rather than accurately weeding out unfit workers, drug testing is just another means of hyper-surveillance and hiring discrimination used against the working class.

With popular track star Sha’Carri Richardson recently suspended from competition in advance of the Tokyo Olympics after testing positive for cannabis use, there’s been an increase in conversation calling out drug testing as yet another racist relic of the war on drugs.

While I’m not convinced of the real-world utility of testing anyone for cannabis, I can understand the trepidation when it comes to potentially failing a random drug test. While everyone’s body metabolizes and eliminates THC at different rates, someone who smokes multiple times a day may have their drug use detected on a urine screening up to one month after putting down the pipe. While the actual time elapsed before a clean screen may be much shorter, that uncertainty can make it impossible for those subject to random drug testing to use cannabis without worrying they’ll lose their livelihoods.

Can cannabis topicals show up on drug tests?

I have good news for those of you who only use topicals, via Dr. Bonnie Goldstein. She’s the Medical Director of Canna-Centers, a California-based medical practice, and was kind enough to answer my questions. “Topical preparations have minimal penetration through the layers of the skin, therefore effects are limited to the local area where it is applied,” she explained.

That means that the cannabinoids in topicals don’t reach the bloodstream, much less the liver, and their metabolites won’t show up on any type of drug test: urine, saliva, even hair or blood. There’s no reason to forgo topical THC or CBD with even the most stringent drug-testing policies in place.

“Both compounds have been shown to have anti-inflammatory, pain-relieving, and anti-itch properties when applied to the skin,” Dr. Goldstein said. “So many people may benefit from topical cannabis, including those with arthritis, post-injury pain, neuropathy, muscle spasms, and those with rashes such as eczema or psoriasis.”

What’s the difference between topical and transdermal cannabis products?

To truly answer this question, we also need to discuss transdermal products, which often appear right alongside topicals in the form of gels, compounds or — most often — drug-delivery patches. To explain how transdermal products interact with our body, I spoke to Dr. Rachel Knox, who advances insight into the endocannabinoid system along with her family of doctors. According to the cannabinoid medicine specialist, “Transcutaneous — or transdermal — cannabinoid products, such as a patch, are designed to deliver cannabinoids deeper into the skin where they can enter the systemic circulation and reach more distant tissue targets.”

These products contain chemical penetration enhancers, ingredients that weaken the skin’s barrier to allow cannabinoids and terpenes to pass through the epidermis, or outermost layer of skin, into the blood-vessel rich dermis. Depending on what sort of patch you select, THC, CBD and/or CBN will circulate through your bloodstream, just like if you popped a gummy or hit a vape pen. 

Unfortunately, that means they could potentially show up on a drug test. “Regardless of the mechanism through which THC was consumed (e.g., through smoking, edibles, or transdermal patch), THC and its metabolites will behave the same once absorbed into the circulatory system,” Dr. Knox said.

While they’re not a good idea for anyone undergoing random drug testing, I recommended transdermal patches to many people during my time as a budtender. It’s an invaluable resource for those who need consistent, long-lasting pain relief to supplement or replace opioid painkillers. Patches are frequently used by cancer patients undergoing radiation or chemotherapy, who may not have the ability to tolerate edibles or inhalation. Along with RSO, it’s a potential alternative to edibles for folks with severe food allergies.

Tips for using topicals and transdermals

If you don’t want a nasty surprise on your next drug screening, it’s vital to know the difference between topical and transdermal products. While they sometimes appear in similar packaging, or in the same section on dispensary menus, they’re meant to serve different purposes.

Before applying any product to your skin, Dr. Knox recommends hopping in the shower for a scrub. “Exfoliation can do a number of things to likely improve product absorption,” she said, such as removing dry and dead skin, unclogging pores, removing chemical agents that may prevent or diminish absorption, and improving blood circulation throughout and under the skin.”

After drying off, topical lotions or balms can be applied directly to the affected area, like an arthritic ankle or a strained bicep. While cannabinoids won’t reach the bloodstream and get you high, they’ll decrease inflammation and pain in that localized area. Don’t allow pets to lick your skin while wearing any product containing THC, as it can be dangerous to many animals.

While some topicals are in neutral carrier lotions, many combine THC and CBD with potent pain-killing ingredients like menthol and borneol to create a tingly effect similar to Tiger Balm or Icy Hot. If you have a preference, pay close attention to product descriptions, or ask your budtender for guidance. 

Transdermal products appear most often as gels, sometimes contained in an easy-to-dose applicator pen, or as patches, similar to a nicotine or birth control patch. If you don’t want to use the whole dosage of a transdermal patch at once, they can generally be cut into halves, quarters or even smaller pieces. 

Since the active ingredients need to penetrate the skin barrier to reach blood vessels, all transdermal formulations work best when applied to a flat area with pronounced, surface-level veins. The inside of the wrist and top of the foot are the two most popular locations.

Dr. Goldstein of Canna-Centers reminded me to watch out for the chemical penetration enhancers that allow the cannabinoids in transdermal products to penetrate deeper into tissue. “Patients should always check the ingredients on these products to make sure that they are not allergic to these chemicals, and to also make sure that they are safe for their particular condition.”

In addition, don’t forget that that innocent-looking transdermal will actually get you high. I’ve tried a patch myself, and despite having a high tolerance, I noticed intoxicating effects within twenty minutes. 

“I only recommend transdermal products to patients who have had some experience with cannabis,” Dr. Goldstein told me. “It is important to know how you react to THC, CBD, or other cannabinoids before applying a transdermal product.”

Featured image by Gina Coleman/Weedmaps

Need advice on how to incorporate cannabis into your lifestyle? Write Cupcake at askabudtender@weedmaps.com