• Muscle stiffness (spasticity): Strong. A THC/CBD mouth spray (nabiximols, Sativex) is approved for this in Canada and much of Europe, though not by the FDA. In patients whose spasticity had not responded to standard drugs, the odds of a meaningful response were more than twice as high on the spray as on placebo.
• Central nerve pain: Moderate. Oral THC products give modest relief.
• Bladder control and sleep: Limited. A 2026 analysis found early signs of benefit.
• Tremor: Not established.
• Slowing MS: Not established.

Compared with standard treatment: Used as an add-on to baclofen or tizanidine, not instead of MS disease-modifying therapy.

Good to know: Many programs try it for about 4 weeks and continue only if stiffness clearly improves.

What to ask for: A balanced 1:1 THC:CBD product by mouth spray or under the tongue, closest to nabiximols. Taking several small doses through the day matches how the trials were run.