Research study · Pharmaceuticals · 2026
Results of an Exploratory Crossover Pharmacokinetic Study Evaluating a Natural Hemp Extract-Based Cosmetic Product: Comparison of Topical and Oral Routes of Administration
Verified on PubMed Oxford CEBM Level 1B: Randomized Controlled Trial
A 2026 pharmacokinetic study in Pharmaceuticals tested thc in pharmacokinetics. The results were clear for the mouth route and very limited for the skin route. This study shows that swallowing this particular cosmetic hemp oil delivered measurable cannabidiol into the blood, while rubbing it on the skin delivered very little, and that some people's urine.
In plain language
Study overview
Twenty healthy adults took a hemp-derived oil product that contains a substance called cannabidiol, either by mouth or rubbed onto the skin, at different times. Blood was drawn over the following day to see how much of the substance entered the body by each route.
Findings
The results were clear for the mouth route and very limited for the skin route. When people swallowed the oil, the cannabidiol showed up in their blood, but when it was applied to the skin, very little got into the bloodstream. Some people who swallowed the product also tested positive on a home urine drug test for marijuana, even though no THC (the intoxicating part of marijuana) was found in their blood, and the researchers do not know why.
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The deeper readScientific analysis
Background: Hemp extracts are used topically as cosmetic products and may be ingested as dietary supplements. Some users report positive carboxy delta-9-tetrahydrocannabinol (COOH-THC) urinary tests following their use. This study evaluated systemic exposure to natural hemp extract-based cosmetic (NHEC) bioactive molecules following a single dose of oral or topical application and assessed urine THC positivity. Methods: Twenty healthy adults (18–50 years, males and females) of a randomized, open-label, single-dose, crossover study received the NHEC orally or topically with a 15-day washout period. Plasma samples were analyzed for cannabidiol (CBD), tetrahydrocannabinol (THC), and their metabolites using a validated liquid chromatography-tandem mass spectrometry method. Pharmacokinetic parameters were calculated by non-compartmental analysis. Urine samples were tested for COOH-THC using commercial test strips. Results: All analytes, except CBD and 7-hydroxy cannabidiol (7-OH-CBD), were below the limit of quantification. Oral NHEC administration resulted in a faster Tmax (3 h vs. 24 h) and a higher AUC 0–24 (281 vs. 19 h·ng/mL) for CBD compared to topical administration. Urine was positive for COOH-THC in 38% of participants receiving an oral dose. Conclusions: A single oral dose resulted in detectable plasma CBD and 7-OH-CBD, whereas topical administration produced low and frequently BLQ CBD concentrations with 7-OH-CBD and THC-related analytes not quantifiable. Urine COOH-THC tests were positive only in participants after oral use of an NHEC but not with topical use. Given the absence of THC in the product and the lack of CBD-to-THC conversion in humans, the cause of urine positivity remains unclear.
The paper
Citation
Jain M, Hudson R, Tarrell A, Green DJ, Clifford JJ, Watt K, et al. Results of an Exploratory Crossover Pharmacokinetic Study Evaluating a Natural Hemp Extract-Based Cosmetic Product: Comparison of Topical and Oral Routes of Administration. Pharmaceuticals (2026). PubMed 41754772 · DOI
Limitations the authors noted
Urine not tested for THC before dosing (no baseline). Small sample (n=20, 18 completers), exploratory, not powered for confirmatory inference. Topical Tmax near end of sampling window; terminal parameters (AUC0–inf, T1/2, CL/F) unreliable and not estimable for topical route. Absolute bioavailability based on historical IV data from different studies, not an IV arm in the same protocol. Single dose only; no fasting-versus-fed or repeated-dose assessment. Industry sponsor (Young Living Essential Oils) funded the study.
In practice
Why this matters
This study shows that swallowing this particular cosmetic hemp oil delivered measurable cannabidiol into the blood, while rubbing it on the skin delivered very little, and that some people's urine tested positive on a marijuana screen without any THC in their blood. It does not establish how these results would apply to other doses, other products, other people, or longer use, and the group was small and followed for only one day. Clinicians should treat the unexplained urine results as an open question rather than proof of anything.
Frequently asked questions
Clinical Questions & Answers
What were the primary clinical findings in this clinical evaluation of cannabinoids?
The results were clear for the mouth route and very limited for the skin route. When people swallowed the oil, the cannabidiol showed up in their blood, but when it was applied to the skin, very little got into the bloodstream. Some people who swallowed the product also tested positive on a home urine drug test for marijuana, even though no THC (the intoxicating part of marijuana) was found in their blood, and the researchers do not know why.
What study limitations or clinical safeguards should patients keep in mind?
Urine not tested for THC before dosing (no baseline). Small sample (n=20, 18 completers), exploratory, not powered for confirmatory inference. Topical Tmax near end of sampling window; terminal parameters (AUC0–inf, T1/2, CL/F) unreliable and not estimable for topical route.
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Reviewed by Dr. Caplan on October 17, 2026.
This page is general education about a published study. It is not medical advice and does not create a doctor-patient relationship. For care specific to you, book a consultation.
