Free prescriptions for long-term cancer patients have now been introduced in England after similar moves in Scotland and Wales.
Although the change will not come into effect until April, patients who are being treated for cancer or its effects can apply now.
All medicines will be covered, including drugs not related to the actual disease, and a five-year certificate exempting patients from charges may be renewed as many times as necessary.
It will save £100 a year in prescription charges for the 150,000 existing cancer patients. Applications must be countersigned by the patient's GP, hospital doctor or service doctor.
Campaigners hope that other chronic conditions will be exempted in the future, which might eventually include five million people suffering from long-term conditions.
The Chief Executive of Macmillan Cancer Support, Ciaran Devane, said: "This was absolutely the right thing to do. Cancer not only threatens your life, but can also make you poor. Free prescriptions will transform the lives of thousands of people living with cancer who were struggling to pay for drugs.".
Meanwhile, the president of the Royal College of Physicians, Professor Ian Gilmore, is studying mechanisms that might be used to usher in a full exemption.
"I am a cancer patient. Last year while having chemo I got a pre-paid presciption as at each visit I came away with five items of medication. I more than got my money's worth. But now I am pleased for others and hope all chronic conditions will soon be covered too." - Joy Wallis, Portsmouth
"I suffer from asthma and chronic osteo-arthritis involving numerous joints. When will these conditions be exempt from prescription charges I have to pay £100 for a prepayment prescription as I am under 60 years of age. This £100 could be used towards my heating costs." - Gillian Halliday, Lincolnshire