Hemp-derived Delta-9-THC is federally legal THC that has been extracted from the hemp plant. Because the 2018 Farm Bill legalized hemp at the federal level, defining hemp as any part of Cannabis sativa that contains a delta-9 THC concentration of no more than 0.3% on a dry weight basis, hemp-derived products and hemp extract are legal, provided they conform to the 0.3% THC limit.

For example, a tincture can have THC in it and sold nationally (check your State's current hemp regulations) if the THC comes from hemp and is no more than 0.3% THC by volume. The extraction process is highly technical, but the THC derived from hemp is still euphoric just like cannabis-derived THC.