Scotland has led the world by becoming the first country to implement a minimum unit price for alcohol, Nicola Sturgeon has said.
The First Minister hailed the policy, designed to cut alcohol-related harm, as "bold and brave" as it was finally brought in across the country.
The minimum 50p per unit price, delayed for six years by a legal challenge led by the Scotch Whisky Association, has been welcomed by the medical professional and health campaigners as the biggest breakthrough in public health since the ban on smoking in public.
It is estimated the move could save around 392 lives in the first five years of its implementation in Scotland, where on average there are 22 alcohol-specific deaths every week and 697 hospital admissions.
The misuse of alcohol is thought to cost Scotland £3.6 billion each year, or £900 for every adult in the country.
Speaking on a visit to Edinburgh Royal Infirmary, Ms Sturgeon said: "Scotland is the first country in the world that is being bold enough and brave enough to implement minimum unit pricing.
"The eyes of the world will very much be on Scotland, not just today but as the benefits of this policy start to be seen and felt.
"Already we see countries across the British Isles - Wales and Ireland - looking to follow suit and I'm sure that as the benefits of this policy start to be seen we'll see other countries elsewhere doing exactly that.
"All of the evidence says that minimum unit pricing will reduce deaths from alcohol-related illnesses, reduce hospital admissions and generally reduce the damage that alcohol misuse does to our society.
"No one has ever said that minimum pricing on its own will resolve all of the problems we have with alcohol misuse but all of the experts who support this policy will also say that without this all of the other things we do will not have as much impact as we want them to."
The Scottish Government has faced calls to go further with policies to tackle the issue, including by increasing the minimum unit price and backing further curbs on the marketing or availability of alcohol.
Ms Sturgeon said the government remained "very open minded to policy ideas", adding: "We need to continue to look at how we do more.
"Within the powers of the Parliament its important that we continue to look at where further action can have a positive impact."
Scotland's chief medical officer Dr Catherine Calderwood said: "As a nation we drink 40% more than the low risk drinking guidelines of 14 units per week for men and women.
"Prior to the implementation of minimum unit pricing, those 14 units could be bought for just £2.52. This is absolutely unacceptable.
"That is where this new legislation comes in, and I am confident that over the first five years of its operation, minimum unit pricing will reduce the number of alcohol-specific deaths by hundreds, and hospital admissions by thousands."
Tory MSP Miles Briggs said his party would "await with interest" the impact of the policy.
He said: "The Scottish Conservatives supported the introduction of a sunset clause, so that if minimum pricing proves to be ineffective then it can be scrapped."
Labour's Anas Sarwar MSP welcomed the move but said a "comprehensive, fully-funded strategy to tackle problem drinking" was needed.
He said: "Labour has made the case for a Social Responsibility Levy to claw back the windfall supermarkets could make from minimum unit pricing. This cash could be reinvested in our NHS and in preventative public health programmes."
Green MSP Alison Johnstone and Scottish Liberal Democrat leader Willie Rennie said the government should consider increasing the 50p rate.
Ms Johnstone said: "We're still of the view that Holyrood must revisit the policy in two years' time and consider the possibility of increasing the 50p rate as part of Scotland's continued efforts to reduce the harm caused by alcohol."
Mr Rennie added: "While this legislation will help to discourage the misuse of alcohol, inflation eroded the value of the original minimum price during the years that this policy has been caught up in the courts."