Patients at a Black Country hospital are to be given cannabis as part of a government-funded trial.
Some patients will receive cannabis-based medicines
The study, which is being run by the Medical Research Council, aims to find out if the drug really can help to relieve pain.
Walsall's Manor Hospital is one of 36 hospitals across the UK, and the only one in the West Midlands, taking part in the £500,000 study.
The Manor Hospital's chief executive, John Rostill, said he was proud that one of the Manor's anaesthetists, an expert in pain control, had signed the hospital up for the tests.
He said: "We're not talking about smoking joints.
"This is to try to work out the protocol to see whether this brings significant pain relief, and is one of the options that people can be given.
"I think people forget that this trust doesn't just meet lots of targets.
"It does participate in things that other people don't always feel they want to get involved in. It's cutting edge, and I'm very pleased."
Randomly-selected patients will be given one of four pills after undergoing surgery, two of which will be a form of cannabis.
They will receive a capsule containing standardised cannabis extract or a capsule containing tetrahydrocannabinol - the active ingredient in cannabis.
The remaining patients will receive either a standard pain-relieving drug or a dummy pill.
Researchers will ask the patients about their pain and general well-being at least once every hour while they are awake, over a six hour-period. The patients will be able to request additional pain relief at any time.
The researchers will then be able to compare the experiences of patients in each of the four groups and, it is hoped, determine whether the cannabis-based treatments are effective.
The trial is being headed by scientists at Imperial College London.