We’ve all suffered from the occasional spontaneous headache. If you’ve experienced migraines before, you’ll know they’re a step up from normal headaches – they cause nauseating pain, blind spots in your vision and pain that can last for hours.

Cluster headaches go beyond even the debilitating pain of migraines. Clinically a different type of headache altogether, they are characterised by severe, excruciating pain focused on one side of the head. An episode can last several hours and can reoccur within a short time period, even several times within the same day. Around one in 500 people suffer from cluster headaches, and some report that their headaches are more painful than childbirth.

Because clinicians don’t understand what causes cluster headaches, treating them is difficult. Current treatments are expensive, unpleasant or impractical – such as inhaling from an oxygen tank or frequent injections. Many medicines, especially preventative ones, cause unpleasant side effects including heart problems and gum disease. An estimated 10-20% of sufferers can’t find relief from any typical treatments. But psychedelic drugs may be able to finally provide relief for those unfortunate few.

New evidence suggests that classic psychedelics such as LSD and psilocybin could treat cluster headaches more effectively than any current medications. A group of researchers surveyed nearly 500 sufferers of cluster headache, asking them about their typical medication habits. The survey showed that psilocybin is as effective as the leading treatments at aborting cluster headaches after they’d already begun – but more remarkably, both psilocybin and LSD were more effective than any other medication at preventing cluster headaches. No serious side effects were reported from the use of either of these psychedelics, used on average about once every few weeks (much less frequently than typical medication).

LSD and psilocybin are more effective at preventing cluster headaches than other treatments. BOL and LSA are molecules with similar structures to the classic psychedelics. Adapted from Schindler et al (2015).

This study adds to a growing list of evidence that psychedelics could be used to treat a huge range of conditions. It’s a clear breach of human rights to withhold potential treatment from suffering people. Researchers should be able to study psychedelic drugs without restriction, in the hope of finding new therapies.

Denying access to psychedelics is at best religious persecution, and at worst withholding treatment from suffering people. It will soon be impossible for policymakers to continue to ignore the mounting pile of evidence – the legalisation of psychedelics is inevitable.

If you suffer from cluster headaches and would like to learn more about alternative treatments, visit Clusterbusters.org