As sciatica is a type of nerve pain (specifically, radicular pain), neurology studies relating to cannabinoids are of great interest. In 2018, one study published in the American Academy of Neurology found that THC can reduce radicular pain. Researchers believe this is down to THC reducing the connection between areas of the brain that are usually heavily connected, thus disrupting pain processing pathway signals.
All participants were male (as hormonal fluctuations in the menstrual cycle may affect pain sensitivity) and had sciatica for at least six months. Six were given a placebo oil, while the remaining nine were given 15mg of THC oil under the tongue. Those who received THC oil reported a significant reduction in nerve pain compared to those given the placebo.
While several clinical studies suggest that cannabinoids significantly reduce neuropathic pain, most of these trials fail to meet the required standards of quality. A 2021 literature review of cannabis for pain concluded that evidence for its efficacy is limited. A Cochrane review of 21 clinical trials involving over 2,100 adult patients noted that most studies fail to provide firm conclusions and that more research is needed.
What causes sciatica, and why it behaves like nerve pain
Sciatica is caused by pressure or damage to the sciatic nerve, which runs from your lower back down your legs. Conditions such as a herniated disc, spinal stenosis, bone spurs and piriformis syndrome can also be causes, and pregnancy can also trigger sciatica.
The sciatic nerve is the largest nerve in the body, and when pressure is put on it, it sends signals to the brain. This can result in radiating pain through the hip, buttock and leg(s); numbness and tingling; and muscle weakness.
How might medical cannabis help sciatic nerve pain? (endocannabinoid system, nerve pain signalling, inflammation, sleep)
Although the efficacy of medical cannabis for sciatica pain is contested, with some patients finding it very helpful and some studies concluding it does not yield significant results, cannabinoid treatment can also be taken for many of the co-occurring symptoms.
The endocannabinoid system, which cannabinoids such as THC and CBD interact with, is the body's internal regulatory system, and it's thought to play a crucial role in the development of neuropathic pain. The ECS is made up of two types of receptors (CB1 and CB2), which can be found throughout the body. CB1 receptors are present in abundance in the central nervous system. THC activates these receptors and may modulate pain signalling in doing so.
Inflammation can also play a major role in sciatica by irritating and sensitising the sciatic nerve, and it's possible CBD could help with this. CBD is well-known for having anti-inflammatory properties, by interacting with receptors like TRPV1 and PPARγ to reduce pro-inflammatory cytokines.
Medical cannabis for sciatica can also help address sleep issues, which often arise as a result of the discomfort. Multiple studies have found that taking THC can decrease the time it takes to fall asleep and decrease wakings in the night, and there's another cannabinoid famed as a sleep aid too: CBN. This minor cannabinoid is present in some medical cannabis strains, and studies have found it may be helpful for improving overall sleep disturbance.
THC and CBD, what is the difference?
THC and CBD are different cannabinoids naturally occurring in the cannabis plant. Although they both interact with the endocannabinoid system and other targets in the body, they work in unique ways. CBD is non-intoxicating and best known for its anti-inflammatory and antioxidant properties, whereas THC activates receptors found primarily in the central nervous system, so it is often looked to as an alternative neuropathic pain treatment.
What forms is medical cannabis prescribed in?
Medical cannabis can be prescribed for sciatica in a variety of forms, including cannabis oil, THC vapes, dried cannabis flower and pastilles.
Where it sits alongside physiotherapy, painkillers and nerve pain medication
Although medical cannabis does interact with some medications, all prescribed cannabis is given under close clinical supervision. When you book your consultation with Releaf, your medical records are sent directly to your consultant, so they will be able to look at the medications you are currently taking and advise accordingly.
Is sciatica eligible for medical cannabis in the UK?
Sciatica patients may be eligible for medical cannabis treatment in the UK, although medical cannabis is not a frontline therapy. Patients must have tried two or more first-line treatments before they can be approved for medical cannabis.
Risks, side effects, and when to seek urgent medical help
If you have sciatica and experience loss of bladder or bowel control, numbness around the groin or inner thighs, or sudden weakness in both legs, it’s important you seek urgent medical assessment rather than a cannabis consultation.
Although medical cannabis is taken under clinical guidance, when taking the appropriate, recommended dose, side effects are possible. The most common side effects of medical cannabis include dizziness, dry mouth, fatigue and impaired co-ordination. Some people can experience symptoms of anxiety. Medical cannabis is not recommended for patients with a history of certain mental health conditions, and your consultant will be able to advise accordingly.
Find out more about how Releaf works, or complete our medical cannabis eligibility checker to see if you could be eligible.
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