Are low-dose cannabis oils safe and effective for MS symptoms? | Research

The takeaway

A prospective study of 28 MS patients found that low-dose medical cannabis oils (mean 4 mg THC, 7 mg CBD daily) were safe and well-tolerated, with significant reductions in pain, spasticity, and sleep disturbances over four weeks without impairing cognitive or physical function.

MS patients considering medical cannabis, neurologists exploring low-dose cannabis treatment options, and anyone interested in the safety profile of medical cannabis oils.

Pain: 7 to 4; Spasticity: 6 to 2.5

What the researchers found

Pain decreased from median NRS 7 to 4 (p=0.01), spasticity from 6 to 2.5 (p=0.01), and sleep disturbances from 7 to 3 (p<0.001). Most common adverse events were mild dry mouth, drowsiness, dizziness, and nausea. Two patients discontinued due to excessive dreaming and drowsiness. No impairment in disability (EDSS), ambulation, dexterity, or processing speed.

Why it matters

The low doses used (mean 4 mg THC) are much lower than typical recreational or even medical cannabis use. Demonstrating safety and efficacy at these doses could make medical cannabis more accessible to patients and clinicians who are concerned about side effects and impairment.

The numbers in context

28 patients; mean THC dose 4 mg, CBD dose 7 mg; mostly once-daily evening; pain NRS 7 to 4 (p=0.01); spasticity 6 to 2.5 (p=0.01); sleep 7 to 3 (p<0.001); 2 discontinuations; 3 SAEs unrelated to treatment; no cognitive/physical impairment

How the study worked

Prospective observational safety study of 28 MS patients treated with medical cannabis oils (THC-rich, CBD-rich, and THC+CBD combined). Four-week titration period with assessments at baseline and 4 weeks including EDSS, T25FWT, 9-HPT, SDMT, blood tests, and plasma cannabinoid levels. Daily NRS ratings for symptoms.

What this study cannot tell us

Small sample (28 patients). No control group; improvements could reflect placebo effect. Short follow-up (4 weeks). Open-label design means patients knew they were receiving cannabis.

How to read the evidence

Prospective safety study with validated outcome measures, but small sample, no control group, and short follow-up.

When this study was published

Published in 2021; low-dose cannabis oil research in MS is still in early stages.

The bigger picture

The "start low, go slow" approach with cannabis oils is increasingly recommended but rarely studied prospectively. This study provides evidence that even very low doses can meaningfully reduce MS symptoms without the cognitive and motor side effects that concern patients and clinicians.

Questions still open

Would a randomized, placebo-controlled trial confirm these findings? Are the benefits sustained beyond 4 weeks? Which cannabis oil formulation (THC-rich, CBD-rich, or combined) is most effective for which MS symptoms?

Common questions

How much cannabis oil do you need for MS?

This study found meaningful symptom relief at very low doses: an average of just 4 mg THC and 7 mg CBD daily, usually taken as a single evening dose. This is much lower than typical recreational doses.

Does cannabis oil affect thinking or walking in MS?

At these low doses, no impairment was detected in disability scores, walking speed, hand dexterity, or processing speed over the 4-week study period.

Read the original research

Safety and efficacy of low-dose medical cannabis oils in multiple sclerosis.

Multiple sclerosis and related disorders, 48, 102708

View on PubMed ↗Publisher’s paper ↗

Citation

S, Gustavsen; Hb, Søndergaard; K, Linnet; R, Thomsen; Bs, Rasmussen; Ps, Sorensen; F, Sellebjerg; Ab, Oturai. (2021). Safety and efficacy of low-dose medical cannabis oils in multiple sclerosis.. Multiple sclerosis and related disorders, 48, 102708. https://doi.org/10.1016/j.msard.2020.102708