The anti-wrinkle drug Botox could soon be offered to patients with chronic migraines by the NHS in England and Wales, according to the medicines watchdog.
It is thought 700,000 people in the UK have chronic migraine.
Final draft guidelines by the National Institute for Health and Clinical Excellence (NICE) recommend Botox when other drugs have failed.
The Migraine Trust said it welcomed the decision.
Migraines are extreme headaches that often come with nausea and being very sensitive to light or sound. To have chronic migraines, a patient must have headaches on at least 15 days a month, eight of which have to be migraines.NHS funding?
Botox was approved as a treatment for chronic migraine in the UK in 2010, and NICE is now considering whether the NHS should fund it.
In February, it said there was insufficient evidence and asked the manufacturer, Allergan, to provide more proof.
Now it believes that Botox should be used in some patients.
Prof Carole Longson, the director of the health technology evaluation centre at NICE, said: "Chronic migraines are extremely debilitating and can significantly affect a person's quality of life.
"We are pleased that the committee has been able to recommend Botox as a preventative therapy for those adults whose headaches have not improved despite trying at least three other medications and whose headaches are not caused by medication overuse."
The final guidelines are expected in June.
NICE estimated the cost to the NHS would be £349.40 for every 12-week cycle of treatment.'Safe and effective'
Exactly how the neurotoxin prevents migraines is unknown. It may work by blocking pain signals or relaxing muscles.
Wendy Thomas, the chief executive of The Migraine Trust, welcomed the recommendation by NICE.
She said: "Chronic migraine is a disabling condition and in many cases ruins people's lives.
"For patients who suffer from this condition, Botox may offer a safe and effective preventative treatment option to help them manage their migraine and improve their quality of life."
Dr Fayyaz Ahmed, chair of British Association for the Study of Headache, said: "The headache experts with first-hand experience in treating chronic migraine know how debilitating the condition can be for some patients, and Botox can be a life changing treatment.
"We are pleased that NICE has recommended Botox for those who have failed to respond to first-line treatments."