The sanctions have not worked, and in some instances have spectacularly backfired. From Ted Snider at antiwar.com:
In February 2022, when Russia invaded Ukraine, the US orchestrated a perhaps unprecedented sanctions clampdown on Russia. A month later, US Treasury Secretary Janet Yellen declared with certainty that “the Russian economy will be devastated as a consequence of what we’ve already done.”
She was wrong. The sanctions on Russia have failed to achieve their primary goal: they have not forced Russia to end its war with Ukraine. They have even failed to achieve the means to that goal: they have not devastated the Russian economy.
Yellen boasted that “We have isolated Russia financially. The ruble has been in a free fall. The Russian stock market is closed. Russia has been effectively shut out of the international financial system.” Not one of those boasts turned out to be true.
It should not be surprising that the sanctions on Russia failed either to force a regime change or a change in the regime’s plans. Years of US led sanctions have not brought about their desired effects in Cuba, Venezuela, North Korea, Iran, Syria or Russia.
Sanctions can have undesired consequences, though. In addition to frequently harming the civilian population more than the government, they can even rally the population behind that government. Sanctions can hurt the people the US is trying to help and help the government the US is trying to hurt. That has been true in the past in Russia. In The Putin Paradox, Richard Sakwa observes that, though past sanctions were meant “to shape Russian policy” or lead to “regime change,” they “tended only to reinforce solidarity around the Kremlin” while they “rallied the country behind Putin.” That seems also to be true today.