Karpyuk was the chairman of the Rivne cell of the Ukrainian National Assembly. In 1992, he participated in the Transnistria War on the side of Transnistria and in the War in Abkhazia, in 1993, he fought on the side of Georgia. He took part in the Ukrainian parliamentary elections of 1998 and 2002 for UNA-UNSO, but the party did not go to the Verkhovna Rada both times.[4]
In 2001-2002, there was a split within the UNA-UNSO. At the congress in November 2001, Mykola Karpyuk was elected as the new chairman of the UNA-UNSO.[5] In 2000-2001, he took part in the action “Ukraine without Kuchma”, because of which he was arrested and sentenced to 4.5 years in prison.[6] In 2004 he was released from prison. During the Euromaidan Karpyuk joined the organization Right Sector and became a leading figure within the organization.[7]
Karpyuk was kidnapped on the Russian-Ukrainian border in 2014 and arrested, according to his family.[8] After his arrest, Mykola Karpyuk, along with another Ukrainian detainee in Russia, Stanislav Klykh, was charged with participation in hostilities during the First Chechen War on the side of the Chechen Republic of Ichkeria, attempted murder, and killings of servicemen of the armed forces of Russia in 1994-1995. The charges were based on the testimony of Alexander Malofeev, who was sentenced to 24.5 years of imprisonment, who allegedly was a member of the Viking detachment. Klykh and Karpyuk themselves denied visiting Chechnya.[9]
Amnesty International has called the trial against Karpyuk and Klykh unfair.[10] Karpuk and Klykh were denied access to lawyers, and alleged that they were tortured while imprisoned.[11] In 2018, Lyudmyla Denisova, the Commissioner for Human Rights in Ukraine, was denied visiting access to Karpyuk and fellow political prisoner Oleg Sentsov.[12]
Mykola Karpyuk was released with swap between Russia and Ukraine, 35 prisoners to 35, on September 7, 2019.[13] When the plane with 35 freed Ukrainians landed in Kyiv, they were met by president Volodymyr Zelensky and relatives.[14]