Cannabis creams and balms are sold for pain, itch and many skin problems. This article checks those claims against trials in people. It also covers whether a cream can make you intoxicated or fail a drug test, how accurate product labels are, and which ingredients cause skin allergy. It ends with a table of the evidence and five checks before you buy, make or recommend a product.
Two facts from Part 1 help with everything below. First, the skin’s outer layer of dead cells (the stratum corneum) is a strong barrier. Cannabinoids prefer oil so strongly that most of them stay in that dead layer instead of reaching living cells. Second, a “topical” product is designed to act in or just under the skin, with little or nothing reaching the blood. A “transdermal” product is designed to pass into the bloodstream, and it is defined by its delivery rate and blood-level data.
This is Part 2. Part 1: Cannabis on the Skin: What Topical Cannabidiol and Tetrahydrocannabinol Can and Cannot Do
1. Localised Pain and Inflammation
Pain relief is the most advertised use of cannabis topicals. Its evidence is among the weakest.
Joint pain. An open-label trial (one where participants knew what they were using) was published in Scientific Reports in 2024. Fifteen people completed it. They used a 4% transdermal cannabidiol (CBD) gel for four weeks. Pain fell by about two points on a ten-point scale, and grip strength improved.
Both gains disappeared during the washout, the period after people stopped using the gel. Expectation alone explains that pattern poorly. The authors listed the limits themselves: there was no placebo group, the sample was small and everyone knew what they were using. A 2022 randomised trial in the Journal of Hand Surgery studied arthritis at the base of the thumb (thumb basal joint arthritis). It also reported a benefit, in only 18 participants.
Nerve pain. Xu, Cullen, Tang and Fang published a randomised, placebo-controlled trial in Current Pharmaceutical Biotechnology in 2020. It included 29 people with peripheral neuropathy (nerve damage) in the legs and feet. Fifteen received a topical cannabidiol oil and 14 received a placebo, for four weeks. The cannabidiol group had significant reductions in intense pain and sharp pain. Cold and itchy sensations also fell.
Taken together, the results point in a good direction and side effects were mild. The samples are far too small to be sure. Other parts of the routine also lower pain scores on their own. These include the carrier oil, the massage of rubbing it in, and counterirritants, which are ingredients that create a cooling or warming feeling.
Translator’s note: Many balms sold in Thailand, including traditional herbal balms (ยาหม่อง), already contain counterirritants such as menthol or camphor. If a cannabis balm also contains them, you cannot tell which ingredient is easing the pain.
What to do: If you try a balm for joint or muscle pain, score your pain from 0 to 10 each day for two weeks. Write down whether you also massaged the area. This shows whether the effect lasts, and whether the massage alone explains it.
2. Itch
The scientific reasoning is strongest for itch. Itch travels along C-fibres, thin nerve fibres without a protective coating (unmyelinated). Their endings sit in the upper dermis and reach into the epidermis. That makes them the shallowest target in the skin. A molecule that penetrates poorly has its best chance of reaching them. Cannabinoid receptors sit on these fibres. They also sit on the mast cells and keratinocytes around them.
Palmitoylethanolamide is a fatty molecule that the body makes itself. It is related to the cannabinoid system but does not switch on cannabinoid receptors directly. Two early, uncontrolled studies tested palmitoylethanolamide creams:
- Ständer, Reinhardt and Luger, writing in Der Hautarzt in 2006, treated 22 patients with prurigo (itchy nodules) or chronic itch. Of the 22, 14 responded, and their itch fell by 86.4% on average.
- Szepietowski and colleagues, in 2005, used a similar cream in 21 haemodialysis patients with uraemic pruritus (itch caused by kidney failure). Itch cleared completely in 38% of them.
Then came a controlled trial. Viße, Blome, Phan, Augustin and Ständer published it in Acta Dermato-Venereologica. They randomly assigned 100 people with chronic itch from dry skin to one of two lotions. One group received a palmitoylethanolamide lotion. The other received the vehicle, which was the same lotion without palmitoylethanolamide. Itch improved a lot in both groups. The active group did slightly better (30.1% versus 24.2%), but the difference was not statistically significant.
This shows how the whole field tends to work. Studies without a comparison group report impressive numbers. Once a vehicle group is added, most of the effect turns out to come from the lotion base itself.
What to do: When a product claims to relieve itch, look for a trial that compared it with the same base without the active ingredient. If no such trial exists, expect most of the benefit to come from moisturising.
3. Intoxication and Drug Testing
An ordinary cream, balm or salve on intact skin does not make you intoxicated. A 2017 study in Forensic Science International put its conclusion in its title. Topical products containing tetrahydrocannabinol (THC) cannot cause a positive cannabinoid result in blood or urine.
There are three real exceptions.
- True transdermal products do cross into the blood. In the 2024 hand osteoarthritis trial, cannabidiol and its breakdown products turned up in every participant’s urine. That is not the same as failing a cannabis test. Standard drug screens look for THC-COOH, the breakdown product of tetrahydrocannabinol, not for cannabidiol. A transdermal product that also contains tetrahydrocannabinol is a different matter.
- Mucous membranes have no stratum corneum. Putting a product in the mouth, vagina or rectum skips the barrier completely.
- Damaged skin has a weak barrier. Broken or inflamed skin lets more through. The people who treat the largest areas often have damaged skin, so they are the ones most exposed.
Translator’s note: If your employer runs urine drug tests, or you drive or operate machinery for work, treat any absorbing product that may contain tetrahydrocannabinol as a risk.
What to do: If you face drug testing, use only products with a batch-matched laboratory report showing tetrahydrocannabinol below the detection limit. Do not put cannabis products on broken skin or mucous membranes. This keeps you away from the three routes that do let tetrahydrocannabinol into the body.
4. What Is Actually in the Jar
Label accuracy
The most rigorous data comes from Spindle and colleagues, published in JAMA Network Open in 2022. Researchers led by Johns Hopkins University analysed 105 hemp-derived topical products bought online and in shops. They looked at the products that stated a cannabidiol amount:
- 18% were overlabelled: they contained more than 10% less cannabidiol than advertised.
- 58% were underlabelled: they contained more cannabidiol than the label stated.
- Only 24% were accurate, within 10% of the label.
Tetrahydrocannabinol was found in 35% of all products. Of those, 11% were labelled tetrahydrocannabinol-free. Another 51% did not mention tetrahydrocannabinol at all.
Hemp seed oil is not cannabidiol
The most common buyer’s mistake comes from the ingredient list. Hemp seed oil appears on cosmetic labels as Cannabis sativa seed oil. It is pressed from the seed and is a good moisturiser. It contains essentially no cannabinoids. This is because cannabinoids form in the resin glands (glandular trichomes) of the flower, not in the seed. Any trace in seed oil is left over from processing.
Cannabidiol extract comes from the parts of the plant above ground. It is a different and more expensive ingredient. A jar can show cannabis leaves and be sold as a cannabis cream while containing nothing but seed oil.
| What you see on the label | What it means | What to check |
|---|---|---|
| Cannabis sativa seed oil | A seed-based moisturiser with no meaningful cannabinoids | Whether a cannabinoid is listed separately |
| Hemp extract, full-spectrum | A vague term; it may not contain cannabidiol | A milligram amount and a laboratory report |
| “500 mg” with no other detail | The total in the whole container, not a concentration | 500 mg in a 500 g jar is only 0.1% |
| “Tetrahydrocannabinol-free” | A claim, not a measurement | The detection limit in the laboratory report |
Reading a certificate of analysis
A certificate of analysis is a laboratory report on one production batch. A useful one meets all of these points:
- it names an independent laboratory, not the brand;
- its batch number matches the product in your hand;
- it is dated;
- it gives a full cannabinoid panel with measured values and detection limits;
- it covers heavy metals, pesticides, solvent residues and microbes.
A report that is undated, has no batch number or was issued by the seller looks like data but proves nothing.
Translator’s note: Cannabis flower in Thailand is a controlled herb under the Notification of the Ministry of Public Health Re: Controlled Herbs (Cannabis), B.E. 2568, in force since 26 June 2025. Advertising flower and selling it online are prohibited. Extracts containing more than 0.2% THC may be licensed only to three kinds of holder: Thai juristic persons that are not “foreign” under the Foreign Business Act B.E. 2542, state agencies, and the Thai Red Cross Society. This comes from the Ministerial Regulation on Cannabis or Hemp Extracts B.E. 2569, in force since 26 April 2026.
Translator’s note: For skin products sold in Thailand, check the label for a Thai FDA (อย.) number. The Thai labelling topic explains what a cannabis product label must show. To find a Thai laboratory that can test a cream or oil, ask other members in the B2B Services: Laboratories section. Ask each laboratory whether its method covers creams and oils, not only dried flower.
What to do: Read the ingredient list before the front of the jar. If it lists only Cannabis sativa seed oil, you are buying a moisturiser. If it claims cannabidiol, ask for a dated, batch-matched certificate from an independent laboratory. This tells you what you are actually paying for.
5. Irritation, Allergy and Patch Testing
In the trials above, cannabinoid creams were generally well tolerated. Most reactions come from the other ingredients in the jar, mainly fragrance terpenes. Limonene and linalool are common in botanical products and in cannabis-derived material itself. In air, both oxidise into hydroperoxides, which cause skin allergy far more readily.
Patch-test studies show this is not rare. Among people tested for suspected contact dermatitis (allergic skin rash), the share who reacted to these hydroperoxides ranged from a few percent to more than 10%, depending on the study. A product that was fine when new can therefore cause a reaction months later.
For any new skin product on sensitive skin, the standard practice is to try a small area first. A suspected allergy is confirmed by formal patch testing. Both are matters for a clinician, not a forum.
Extra caution applies in these cases:
- broken or weeping skin;
- a known allergy to fragrance or plants;
- an active skin infection;
- children;
- pregnancy and breastfeeding;
- workplace drug testing;
- eczema or psoriasis that is under prescribed treatment.
The last case carries the biggest risk. Replacing effective treatment with an unproven cream does more harm than the cream itself.
Translator’s note: Rooms in Thailand often sit at 30–35 °C. Heat generally speeds up oxidation. Keep jars tightly closed, out of the sun and in the coolest place available. Write the opening date on the lid. Choose a size you will finish soon.
What to do: Stop using a product that starts to sting or smells different from when you opened it. Show the jar to a doctor if a rash appears. This catches an oxidised-fragrance allergy before it spreads.
6. The Evidence at a Glance
| Topic | Best type of evidence | Size | What it shows |
|---|---|---|---|
| Acne, laboratory | Cultured oil-gland cells and skin in a dish | Oláh 2014 | A reason to test only |
| Acne, in people | Randomised, vehicle-controlled | 368 patients | Main target not met |
| Psoriasis, laboratory | Cultured keratinocytes | Wilkinson 2007 | A reason to test only |
| Psoriasis, in people | Randomised, split-body | 51 | Favourable trend |
| Eczema, palmitoylethanolamide | Randomised, controlled | 72 enrolled | Modest but real benefit |
| Eczema, cannabidiol | Uncontrolled study | 20 (5 with eczema) | Too early to judge |
| Itch, controlled trial | Randomised, vehicle-controlled | 100 | No significant difference |
| Joint and nerve pain | Small randomised and open-label trials | 15 and 29 | Too small to be sure |
7. Five Checks Before You Buy, Make or Recommend a Product
- Does the label state the cannabinoid amount in milligrams and give the container size? You need both numbers to work out the real concentration.
- Is there a dated, batch-matched certificate of analysis from an independent laboratory? It is the only proof of what is in the jar, including tetrahydrocannabinol.
- Does the ingredient list name an actual cannabinoid, or only Cannabis sativa seed oil? This tells you whether it is a cannabinoid product or a moisturiser.
- If it says “transdermal”, is there delivery-rate or blood-level data? Without it, treat the product as an ordinary topical.
- Has the skin or joint problem been discussed with a clinician? Standard treatments have far stronger evidence, and stopping them causes the most harm.
Share Your Experience
If you have used a cannabis skin product for a skin or joint problem, post your experience below with the full ingredient list. Include three details: what was actually in it, whether a batch-matched certificate of analysis existed, and whether any effect lasted longer than two weeks. Personal reports are not medical evidence. Honest reports are still more useful than another round of product claims, including reports where nothing happened.
References
- Open-label trial of a 4% transdermal cannabidiol gel in hand osteoarthritis (15 completers). Scientific Reports, 2024.
- Randomised trial in thumb basal joint arthritis. Journal of Hand Surgery, 2022.
- Xu, Cullen, Tang, Fang. Topical cannabidiol oil in lower-limb peripheral neuropathy. Current Pharmaceutical Biotechnology, 2020.
- Ständer, Reinhardt, Luger. Palmitoylethanolamide cream in prurigo and chronic pruritus. Der Hautarzt, 2006.
- Szepietowski and colleagues. Palmitoylethanolamide cream in uraemic pruritus, 2005.
- Viße, Blome, Phan, Augustin, Ständer. Palmitoylethanolamide lotion versus vehicle in chronic pruritus from dry skin. Acta Dermato-Venereologica, 2017.
- Study concluding that topical tetrahydrocannabinol products cannot cause a positive cannabinoid finding in blood or urine. Forensic Science International, 2017.
- Spindle and colleagues. Label accuracy of 105 hemp-derived topical products. JAMA Network Open, 2022.
- Consecutive patch-test studies of limonene and linalool hydroperoxides (for example, a series of 821 patients and a Danish series of 6,719 patients).
- Studies in the evidence table also covered in Part 1: Oláh and colleagues, Journal of Clinical Investigation, 2014; Botanix Pharmaceuticals, BTX 1503 Phase 2 results, October 2019; Wilkinson and Williamson, Journal of Dermatological Science, 2007; Puaratanaarunkon, Sittisaksomjai and colleagues, 2022; Rao, Moussa, Erickson, Briskey, Skin Pharmacology and Physiology, 2024; Palmieri and colleagues, 2019.
This article is part of the Asiannabis Community educational series on medical cannabis. It is general information, not medical advice. Treatment decisions belong with a licensed practitioner. Content is for educational purposes within jurisdictions where medical cannabis is legally permitted.