A new Isa comparison site, including Innovative Finance Isas, has been launched directly to potential investors.
Apples for Oranges will allow customers to shop around for Isas and be able to see the different returns from stocks and shares, cash and innovative finance Isas in the same place.
"We have found that people do not understand the full extent of the options available in the market,” said James Dean, spokesman for Apples for Oranges.
"All types of Isas will still fall under the tax-free wrapper set out by the government, but when comparing a Cash Isa to an Innovative Finance Isa, you are really comparing apples to oranges, because they are so different."
Announced in the 2015 Summer Budget as a way to spark investment in small businesses, and launched in April 2016, the Innovative Finance Isa allows savers to invest in peer-to-peer lending arrangements without tax on the gains.
Figures last Autumn showed that investors had put just £17m into Innovative Finance Isas in their first year in existence, according to data from HM Revenue & Customs, significantly less than both stocks and shares Isas and cash Isas, which had £22bn and £39bn put into them respectively during 2016 to 2017.
Alan Chan, director and Chartered financial planner at IFS Wealth & Pensions in London, said he did not advise clients to use the Innovative Finance Isa.
He said: "It is certainly not safe. It is still relatively new, and there are some concerns surrounding liquidity and they are also not covered by the Financial Services Compensation Scheme if the underlying company goes bust
"For the same risk there are other investments that can possibly provide better returns over time, for example, through a stocks and shares Isa with mixed assets such as stocks and bonds."