Skinny Mediterranean, Skinny Indian and Skinny Aromatic are the most popular tonic products based on sales, according to the online retailer.
“We believe this is unprecedented for a brand to take all three of the top positions at one time,” said Steve Wilkinson, a founding director of Skinny Tonic.
“Skinny Ginger is also doing extremely well in its own category, currently the third best selling ginger ale.”
Wilkinson added the cucumber tonic would have been in the top 10 but it went sold out two weeks ago, and should be back available shortly.
Privately-owned Skinny Tonic was founded in 2014 by former Domino’s Pizza franchisee Ian Minton who, as a Type-1 diabetic, wanted to mix his gin with a sugar-free tonic.
The firm Skinny Tonic raised £1.565mln in a three-time oversubscribed placing through Seedrs in January.