CBD and methotrexate: what I'd want to know as an RA patient who took both
I was on methotrexate earlier in my RA history, before I discovered CBD. I didn't navigate them together directly, so I can't speak from personal experience the way I can about prednisone. What I can tell you is what I researched carefully when building Reclaim, and what I'd want to know if I were in your position today.
Here's the mechanism. Methotrexate leaves the body mainly unchanged through the kidneys, with a small share converted in the liver by aldehyde oxidase, so the CYP enzymes CBD is known to inhibit aren't a meaningful route for clearing it. The overlap that matters is the liver itself. MTX is monitored with regular liver function tests because it can affect the liver, and CBD at high doses has raised liver enzymes in some people: in Watkins 2021, 7 of 16 healthy adults (44%) taking 1,500 mg/day had ALT above the normal range. That's far above typical wellness doses, but it's why your rheumatologist needs to know you're adding CBD, so your scheduled blood tests are read with that in mind.
Don't adjust MTX on your own. That's not a legal disclaimer, MTX is a drug with a narrow therapeutic window and the titration belongs with your rheumatologist.
What you need to know
- MTX is cleared mainly by the kidneys, not by the CYP enzymes CBD inhibits, so CBD isn't expected to push MTX levels up the way it can for CYP-cleared drugs.
- The shared concern is the liver: MTX can affect it, and high-dose CBD has raised liver enzymes in some people (Watkins 2021). No MTX-specific CBD trial exists, so treat this as something to monitor, not ignore.
- Your existing CBC and liver function monitoring (standard MTX protocol) is the right safety net, make sure your rheumatologist knows you're adding CBD so they're watching for the right things.
- Format matters: topical CBD has minimal systemic absorption and the lowest CYP impact. If you want to start cautiously, the NANO roll-on is the lowest-risk entry point.
- Start low, titrate slowly. MTX has a narrow therapeutic window, don't add high-dose CBD at the same time you're adjusting MTX.
What the science says
The liver-enzyme evidence
Watkins 2021 gave 16 healthy adults 1,500 mg/day of CBD for about 3.5 weeks in a phase I trial. Seven (44%) had peak ALT above the upper limit of normal, all beginning within 2–4 weeks of starting CBD. That dose is far higher than typical wellness use, but it's the clearest human data on CBD and the liver, and it's the reason liver monitoring is the right overlap to watch when MTX is in the picture.
CBD and CYP enzymes (general context)
CBD does inhibit several CYP enzymes. In Bansal 2023, a randomized crossover trial in 18 healthy adults, a single 640 mg CBD dose (with 20 mg THC) raised exposure to CYP2C19, CYP2C9 and CYP3A probe drugs by 207%, 77% and 56% respectively. Yamaori 2011 showed CBD inhibits CYP3A enzymes in vitro. That matters for drugs cleared by those enzymes; methotrexate isn't one of them.
The breadth
Stöllberger 2023 reviewed 403 CYP-substrate drugs and concluded CBD has pathway overlap with 67–68% of frequently prescribed medications. That's why interaction questions come up for almost any prescription. Methotrexate is a less typical case, because it isn't primarily a CYP-cleared drug.
MTX-specific evidence - the honest gap
There is no MTX-CBD interaction RCT. The closest published parallels are case reports of CBD interacting with other immunosuppressants - Cuñetti 2024 reported a pharmacokinetic drug interaction between CBD, cyclosporine and mycophenolate in a kidney transplant patient. Nachnani 2024's 31-report systematic review similarly catalogs tacrolimus, sirolimus, and warfarin interactions but no MTX-specific case.
What this adds up to
A CBD-driven rise in MTX levels isn't supported by how MTX is cleared. The overlap worth managing is the liver: both drugs can move liver enzymes, and CBD's effect on them varies from person to person. Your routine MTX blood tests are already built to catch that.
The mechanism
Methotrexate is eliminated mainly unchanged by the kidneys. A smaller share is converted in the liver to 7-hydroxy-methotrexate by aldehyde oxidase. Inside cells, MTX works through the folate pathway. CYP enzymes are not a meaningful clearance route.
CBD is broken down in the liver and inhibits several CYP enzymes, which is why it interacts with CYP-cleared drugs. Because MTX doesn't depend on those enzymes, the practical overlap is on the liver itself rather than on MTX clearance.
Because MTX leaves mainly through the kidneys, kidney function is what most affects your MTX levels, which is one reason your rheumatologist tracks it alongside liver tests. See the CYP450 mechanism explainer for the foundational pharmacology.
What this means for you
- Talk to your rheumatologist before starting CBD. Bring this page if helpful. The liver-monitoring framing helps the conversation move from "I don't know" to specifics.
- Folate monitoring. MTX therapy requires folate supplementation. CBD's effect on the folate pathway hasn't been studied; if you're already on folate, your rheumatologist may want to monitor levels more closely after CBD initiation.
- CBC + LFT monitoring. Standard MTX monitoring (CBC and liver function tests every 8–12 weeks per ACR guidelines) becomes especially important when CBD is added. CBD can elevate liver enzymes at high doses (Watkins 2021), and MTX can also affect the liver, so this is the overlap worth watching.
- Format choice. Oral CBD passes through the liver first, and the liver-enzyme signal comes from high oral doses. Topical CBD (the Reclaim NANO roll-on) has minimal systemic absorption. Transdermal patches (the 50mg patches) deliver CBD systemically but bypass first-pass. If you choose to combine, your rheumatologist may prefer the lower-systemic-exposure format.
- Dose conservatism. If you and your rheumatologist agree to try CBD, start at the low end (10–25mg) and titrate slowly. See our titration protocol for the ramp.
- Don't change MTX without your rheumatologist. Reclaim does not recommend stopping or reducing MTX based on CBD use.
- Other autoimmune-stack interactions. If you also take a biologic, prednisone, or hydroxychloroquine, see the per-medication pages for each.
Methotrexate brand names
| Brand name | Generic | Form |
|---|---|---|
| Rheumatrex | Methotrexate | Oral tablet |
| Trexall | Methotrexate | Oral tablet |
| Otrexup | Methotrexate | Subcutaneous auto-injector |
| Rasuvo | Methotrexate | Subcutaneous injection |
Subcutaneous MTX (Otrexup, Rasuvo) bypasses first-pass metabolism somewhat, which slightly changes the metabolic profile. This page applies to both routes; either way MTX is cleared mainly by the kidneys and the liver-monitoring point stands.
Frequently asked questions
Can I take CBD if I'm on methotrexate?
Yes, with your rheumatologist in the loop. MTX is cleared mainly by the kidneys, not by the CYP enzymes CBD inhibits, so CBD isn't expected to raise MTX levels. The overlap is the liver: MTX can affect it, and high-dose CBD has raised liver enzymes in some people (Watkins 2021). The practical implication is that your existing monitoring (CBC, liver function) matters, not that you can't use CBD. Tell your rheumatologist and keep your scheduled blood tests.
Is the topical roll-on or transdermal patch safer with methotrexate than the oil?
Possibly — at least from a liver-exposure perspective. Oral CBD passes through the liver first, and the liver-enzyme signal in studies comes from high oral doses. Topical CBD has minimal systemic absorption. Transdermal patches deliver CBD systemically but at lower peak concentrations than oral. If your rheumatologist supports a CBD trial, the lower-systemic-exposure formats keep the load on your liver lower.
What about CBD and MTX side effects? Can it help with the nausea?
No clinical trial exists for this specifically, but CBD has well-documented antiemetic mechanisms and many people report GI relief. The honest answer: it may help, and it's worth discussing. But if MTX side effects are severe, the first conversation is with your rheumatologist, dose, timing, route, and folate are levers they control. CBD is a parallel track, not a substitute for that conversation.
I take MTX once a week. Does the timing of CBD relative to MTX matter?
No study has looked at CBD timing around weekly MTX, and because MTX is cleared mainly by the kidneys rather than by the enzymes CBD affects, there's no established reason to space them apart. What matters more: tell your rheumatologist what CBD you take and how much, and keep your scheduled blood tests so any change in liver enzymes is caught early.
Will my rheumatologist know about this?
Maybe, maybe not. A 2018 Arthritis Foundation survey found 58% of patients who told their doctor about CBD use did not get the safety, dosing, or interaction information they were looking for. Many rheumatologists are under-informed because CBD-Rx interaction research is recent. Bring this page to your appointment. The liver-monitoring framing helps the conversation move from "I'd avoid it" to "let's discuss your monitoring."
References
- Bansal S et al. (2023). Evaluation of Cytochrome P450-Mediated Cannabinoid-Drug Interactions in Healthy Adult Participants. PMID 37313955
- Watkins PB et al. (2021). Cannabidiol and Abnormal Liver Chemistries in Healthy Adults: Results of a Phase I Clinical Trial. Clin Pharmacol Ther. PMID 33022751
- Stöllberger C, Finsterer J. (2023). Interactions between cannabidiol and commonly used prescription drugs. PMID 37541924
- Yamaori S et al. (2011). Potent inhibition of human cytochrome P450 3A isoforms by cannabidiol. Life Sci. PMID 21356216
- Cuñetti L et al. (2024). Drug-Drug Interaction Between Cannabidiol, Cyclosporine, and Mycophenolate Mofetil: A Case Report. PMID 38212169
- Nachnani R et al. (2024). Cannabidiol-prescription drug interactions: a systematic review. PMID 38868665
Related reading
Some related pages are still being written.