Cancer Research UK’s Dryathlon campaign has raised almost £5m so far.
More than 50,000 people, known as dryathletes, signed up to take part in the fundraising campaign, compared with 35,000 that took part in the inaugural event last year, which raised £4m.
It asks people to get sponsored to give up alcohol for the month of January and donate the money they would have spent to the charity.
A spokeswoman for CRUK said the campaign’s JustGiving pages close at the end of February and an updated fundraising total would be available then.
Alcohol Concern reported that the number of people who took part in its Dry January campaign almost quadrupled this year.
The charity said that more than 17,300 people signed up to take part in the campaign this year, compared with 4,350 in 2013.
It said that fundraising was an optional part of the campaign but the main aim was to raise awareness of drinking and the health problems associated with alcohol.
A spokeswoman said fundraising money was still coming in and she would not share the total raised so far.