Cannabis gets asked to do two different jobs in ALS. The first is symptom relief: the stiffness, the cramps, the drooling, the pain, the lost appetite and the bad nights that come with a disease that takes motor neurons one at a time. The second is slowing the disease itself. The evidence for those two jobs sits at opposite ends of the shelf.
Here is where we land. For spasticity, a THC and CBD product is a reasonable thing to raise with the ALS clinic, because the European Academy of Neurology's 2024 guideline lists cannabinoids alongside baclofen, tizanidine and gabapentin, on the strength of one 59-patient trial. For cramps, the one THC trial came up empty. For slowing ALS, no human trial has shown it, and the one placebo-controlled trial built to test it has never published a result. A gummy marketed to slow ALS is selling a mouse study.
Does cannabis help ALS symptoms?
For spasticity, modestly, in one trial. CANALS, a 2019 Italian trial of the THC and CBD spray nabiximols, improved muscle tone scores over six weeks against placebo. For cramps, a THC trial found nothing. For drooling, appetite, pain and sleep, the evidence is patient surveys, and the ALS guidelines treat those symptoms with other drugs.
The agenda was set in 2001, when Carter and Rosen, writing from the University of Washington's rehabilitation medicine department, argued in a review that marijuana should be considered in ALS where it is legal, listing pain relief, muscle relaxation, bronchodilation, saliva reduction, appetite and sleep. That paper had no patients in it. The first survey came three years later from Carter's group in Seattle: of 131 people with ALS who answered, 13 had used cannabis in the past year, and they rated it moderately effective for appetite loss, depression, pain, spasticity and drooling, and useless for speech and swallowing. Thirteen respondents is a focus group with ambitions.
A French survey in 2023 found more users and the same pattern. Of 129 respondents, 28 (21.7%) used cannabis for ALS symptoms, mostly CBD oil and herbal cannabis, and reported benefit for rigidity, cramps, sleep, pain and mood. Eight reported minor side effects, dry mouth among them.
What did the nabiximols trial find for ALS spasticity?
A small benefit on the clinician's own scale. In CANALS, 59 patients at four Italian motor neuron disease centres took nabiximols or placebo for six weeks. Modified Ashworth scores improved by 0.11 on the drug and worsened by 0.16 on placebo, no one withdrew from the blinded phase, and there were no serious adverse effects.
Every participant stayed on a stable antispasticity drug, so the spray was tested as an add-on. Patients titrated themselves over the first 14 days to a ceiling of 12 sprays in 24 hours, each spray carrying 2.7mg THC and 2.5mg CBD, which puts the ceiling at 32.4mg THC a day.
The Ashworth result is the odd part. In multiple sclerosis, cannabinoids spent twenty years mostly failing that same scale while passing the patient's own rating, a story told on our MS spasticity page. In ALS it passed the clinician's scale on the first try, with 59 people. The authors called it proof of concept and asked for larger trials, and seven years on, no larger trial has appeared in the indexed literature. The EAN panel still made the call: consider cannabinoids, baclofen, tizanidine or gabapentin for stiffness and increased tone, a weak recommendation.
A gummy is swallowed, so it follows edible timing, with onset 30 minutes to 2 hours after eating and the main effects lasting 4 to 8 hours, per our edible timing guide.
Does THC help ALS muscle cramps?
No trial says so. Weber and colleagues gave 27 people with ALS and moderate to severe daily cramps 5mg of oral THC twice a day or placebo, two weeks each, in a Swiss crossover. Among the 22 with complete data, THC did no better than placebo on cramp intensity, cramp count, sleep, appetite or mood.
That is still the only trial anywhere that made ALS cramps its primary endpoint, according to the 2012 Cochrane review, which looked at 20 studies and 4,789 participants and found no intervention with a demonstrated benefit. The 2024 EAN guideline lists sodium channel blockers (ranolazine, quinine sulfate, mexiletine, carbamazepine), gabapentin, pregabalin and baclofen for cramps. Cannabinoids appear one paragraph later, under spasticity, and nowhere in the cramps list.
Can cannabis slow ALS progression?
Nobody has shown it in people. The disease-slowing case rests on mice carrying a human SOD1 mutation, in which THC delayed motor decline and extended survival. No human trial has shown that cannabis slows ALS, and the one placebo-controlled trial designed to test it has not published a result.
Raman and colleagues reported the THC result in 2004: given at the onset of tremors, it delayed motor impairment and prolonged survival in SOD1 G93A mice. A year later Weydt's group pumped CBN under the skin of the same mouse strain and delayed symptom onset by more than two weeks, with survival unchanged. When an Australian team pooled seven mouse survival studies in 2019, the gain came to 3.84 days, with a confidence interval running from 0.35 to 7.32 days and a risk of bias the authors rated moderate to high.
That same team then built the human test. EMERALD, at Gold Coast University Hospital, planned to give 30 people with ALS, symptoms for under two years, a high-CBD, low-THC extract or placebo for six months and measure decline on the ALS functional rating scale and breathing capacity. Its ClinicalTrials.gov record lists 17 enrolled, a last update in April 2023, a status of unknown and no results. A 2025 review in Muscle and Nerve, co-written by Carter and Weydt, still ends by calling for trials of cannabinoids as a disease-modifying therapy, which is where the 2001 review ended too.
Is CBD good for ALS?
There is no published human trial of CBD in ALS to say so. The only one registered with that aim, EMERALD, enrolled 17 of a planned 30 and has posted no results. What the CBD label does document is an interaction that touches ALS medicines, through a liver enzyme called CYP1A2.
The Epidiolex label calls CBD a weak CYP1A2 inhibitor and names tizanidine, one of the EAN's spasticity drugs, as a substrate whose levels can rise. In the label's caffeine study, 750mg of CBD twice a day nearly doubled caffeine exposure (area under the curve up 95%). The riluzole label lists riluzole as a CYP1A2 substrate and warns that CYP1A2 inhibitors can increase its side effects. Both drugs also carry liver warnings: riluzole needs liver enzyme tests before and during treatment, and Epidiolex can cause dose-related rises in the same enzymes. That 1,500mg a day is far above any retail gummy, and no study has tested a gummy with riluzole. The clinic still needs to know.
What about drooling, appetite, pain and sleep?
Here the cannabis case is mostly patient report. Survey respondents describe less drooling, better appetite and less pain, and a few report a dry mouth. The ALS guidelines treat drooling first with anticholinergic drugs and botulinum toxin, and their pain advice starts with finding the cause.
The EAN puts anticholinergics (amitriptyline, atropine, glycopyrrolate, oxybutynin, scopolamine) first for drooling, and the AAN's 2009 practice parameter backed botulinum toxin B for drooling that resists other treatment. The EAN also tells clinicians to warn patients that sugary and acidic drinks, milk and juice can stimulate saliva, which is an unflattering footnote for the fruit-flavoured cannabis soda. Nerve pain gets its own treatment path, covered on our neuropathic pain page.
The appetite case for THC in older adults is thinner than its reputation (see our appetite loss page). The EAN's insomnia review found no trials at all, so its sleep advice is consensus.
Is a gummy safe if swallowing has changed?
That question belongs to a speech and language therapist. The EAN guideline sends swallowing difficulty to the dietitian, speech therapist and occupational therapist for advice on food consistency, fluid consistency and choking risk. A gummy is a chewy solid and a cannabis drink is a thin liquid, and either one can be the wrong texture.
The guideline also asks clinicians choosing any muscle treatment to check whether the person has trouble swallowing medicine. Riluzole itself comes in more than one shape for that reason: alongside the tablet there is a thickened oral suspension (Tiglutik, FDA-approved in 2018), and there was an oral film (Exservan, approved in 2019, now listed as discontinued). The dispensary shelf offers gummies. No source we found addresses cannabis products given through a feeding tube, so this page has nothing to say about it.
Which drugs change the course of ALS?
Riluzole, for everyone, and tofersen, for the small group with SOD1 mutations. In the Cochrane pooled analysis, riluzole extended median survival from 11.8 to 14.8 months. Tofersen won FDA accelerated approval on April 25, 2023, on a blood marker of nerve damage. Relyvrio, approved in 2022, was pulled from the market in April 2024.
The EAN tells clinicians to offer lifelong riluzole at diagnosis, 50mg twice a day. It does not recommend edaravone outside a trial, though the FDA approved it intravenously in 2017 and as an oral suspension in 2022. Tofersen's phase 3 trial, VALOR, missed its primary functional endpoint at 28 weeks (a 1.2-point difference, P = 0.97), and its label ties the accelerated approval to falling plasma neurofilament light chain, with continued approval contingent on confirmatory trials. The EAN still offers it first-line in progressive SOD1-ALS.
Relyvrio is the cautionary one. Amylyx announced on April 4, 2024 that it would withdraw the drug after its phase 3 PHOENIX trial, and it stopped taking new patients that day. A licensed drug lost its market when its confirmatory trial came back. Any cannabis product claiming to slow ALS is making that same claim with no trial at all.
What if I already use cannabis for ALS symptoms?
Tell the ALS clinic team, keep the riluzole, and keep the clinic plan. The riluzole label asks for liver tests before and during treatment, CBD carries its own liver-enzyme warning, and CBD slows the enzyme that clears both riluzole and tizanidine. The team can only watch for those if it knows.
The AAN's 2009 parameter recommends considering referral to a multidisciplinary ALS clinic to prolong survival (Level B), and that team is who should hear about the gummy. Sedation is the other thing to raise. The Epidiolex label warns that CBD adds to the sleepiness from other CNS depressants, and baclofen and gabapentin are both on the EAN spasticity list. In CANALS, patients increased the dose gradually over two weeks while their existing antispasticity drugs stayed fixed, which is the closest thing to a protocol the ALS trial literature offers.