Sanofi's highly-anticipated diet pill Acomplia (rimonabant) was formally launched on June 28th in Britain with the announcement that the diet drug can be purchased starting today for just over $100 per month by patients who obtain a prescription from a general practitoner.

The revolutionary weight-loss drug, which still has not been approved for sale in the United States, was given official European Union marketing approval last week.

However, millions of people in Britain who receive their medical care and medicines through the National Health Service are not expected to be able to obtain Acomplia for many months.

Britain's Primary Care Trusts -- the local NHS entities that provide guidance to general practitioners and pharmacists -- are not expected to make Acomplia widely available until it is approved by the independent National Institute for Health and Clinical Excellence, a process that may take a couple of years.

The National Institute for Health and Clinical Excellence (NICE) advises Primary Care Trusts on which treatments are cost-effective, significantly delaying the availability of new drugs to many in Britain.

The United Kingdom is the first place in the world where Acomplia is being launched with roll outs expected later this year in Denmark, Ireland, Germany, Finland and Norway.

At the announced U.K. price of 55.20 pounds for a four-week supply, a 20 mg Acomplia pill -- which needs to be taken each day before breakfast -- is selling for approximately $3.55.

Within hours of the launch announcement in London, at least one online Canadian pharmacy was advertising a four-week supply of the diet pills for $165.

At least in theory, British doctors are only supposed to prescribe Acomplia to obese people (BMI over 30) or overweight people with other risk factors such as diabetes.

"We believe the right patient for Acomplia is overweight with type two diabetes or low levels of good cholesterol (HDL) or high levels of bad blood fats," a Sanofi spokesperson said. "It will benefit these people the most because it will also provide improvement above and beyond weight loss alone."