Speaking at an IPPR policy think tank event, the First Minister suggested the actions of the Conservatives appear at odds with their promises to strengthen protections as a result of the UK's departure from the EU.
Concerns have been raised the Tories will fail to honour those pledges as they press ahead with Boris Johnson's Brexit deal at Westminster.
Earlier, she said Scotland is redefining what it means to be a successful nation by focusing on the well-being of its people as well as economic growth.
She told the Wellbeing Economy Alliance event in Edinburgh, that the "goal and objective of all economic policy should be collective well-being".
Ms Sturgeon added: "This broader approach is at the very heart of our economic strategy, which gives equal importance to tackling inequality as economic competitiveness."
Later, at the IPPR event at the National Museum of Scotland, she accused the UK Government of undermining "so much of what we're trying to achieve" with its approach to Brexit.
She said: "When we look at the changes that were made to the EU Withdrawal Agreement during the negotiations last October, for trading goods the old Theresa May Political Declaration said that the UK's relationship with the EU should be as close as possible - that reference has gone.
"In addition, references to compatible regulatory approaches, full alignment with EU rules and pledges on environmental and workers' rights have all been weakened or removed.
"So although we've heard promises that Brexit won't lead to lower standards, I think the actions so far appear to point to a different direction of travel, which is a move away from EU standards."
The First Minister added: "I think that approach leaves wide open the prospect of doing one thing that would harm Scotland, weakening our social and environmental protections, in order to do another thing which will harm Scotland, weakening our trade ties with Europe.
"The Scottish Government will do everything we can to oppose that direction of travel."